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Rationalization methods in computer aided fabrication: A critical review
Abstract
Rationalization is widely recognized as an important design strategy in contemporary architectural projects, especially in projects with complex geometries, built using digital fabrication processes. However, an up to date review of the rationalization strategies used in these projects, their place in the design sequence and their relation to digital fabrication processes has not been conducted. The purpose of this review is to identify the rationalization strategies used in architectural projects in the practice and the academia.
This paper presents the results of a systematic review of over 500 papers describing rationalization and digital fabrication in contemporary architecture. Using the data gathered in the review, we show that the capabilities of the fabrication machinery used are the most frequently encountered rationalization constraint in realized architectural projects. Additionally, we describe a new taxonomy for rationalization strategies, which incorporates functional information with the temporal information described by traditional classifications. Using this taxonomy, we identify trends within the industry and the academia and point to the growing popularity of parametric co-rationalization approaches. We conclude by discussing promising rationalization approaches for future research.
... Hence, assemblies are widely used in our daily lives that most of our consumer products, industry machines, and architectural structures are in the form of assemblies. Modeling assemblies, particularly for those representing freeform surfaces, is a complex process, because it requires balancing multiple objectives [Austern, Capeluto, and Grobman, 2018]. These include ensuring geometric compatibility among assembly parts, maintaining structural integrity and stability, and achieving the desired aesthetic or functional properties. ...
... To model assemblies with discrete equivalence classes, a straightforward approach is to model assemblies with a set of pre-defined template elements, a process known as prerationalization [Austern, Capeluto, and Grobman, 2018]. Existing works develop computational approach to approximate given freefrom surfaces with Lego bricks [Testuz, Schwartzburg, and Pauly, 2013;Luo et al., 2015], a set of pre-defined triangles [Liu et al., 2021] or a Zometool construction set Zimmer and Kobbelt, 2014] containing nine struts of different lengths and one universal joints. ...
... Instead of directly reusing the polygons, other works aim to reuse molds that are used to fabricate curved panel elements [Eigensatz et al., 2010] or triangle-based point-folding elements [Zimmer et al., 2012], in which elements of the same shape are fabricated with molding and then cut into different sizes and forms for making the architectural surface. The above works optimize specific discrete equivalence classes for different input surfaces, a process known as post-rationalization [Austern, Capeluto, and Grobman, 2018]. In contrast, Liu et al. [Liu et al., 2021] addressed the pre-rationalization problem of modeling various input surfaces using predefined discrete equivalence classes of triangles by developing a fabrication-error-driven remeshing algorithm. ...
An assembly comprises parts joined together to achieve a specific form or functionality. Compared to monolithic objects, assemblies have many benefits in terms of fabrication, transportation, and adaptability. Parts of assemblies are always geometrically simple to fabricate with digital techniques, can be efficiently packed for transportation, and offer adaptability through flexible replacement or modification. Hence, assemblies are widely used in our daily lives that most of our consumer products, industry machines, and architectural structures are assemblies.
This thesis focuses on the computational design of complex assemblies with discrete equivalence classes, where the assembly parts are inversely computed instead of being pre-defined, a process known as post-rationalization. Parts falling into the same discrete equivalence class should have exactly the same shape. A discrete equivalence class, known as a template element, can take various forms, such as shells, rods, nodes, or tiles, depending on the type of assemblies. An assembly with discrete equivalence classes is formed by assembling the instances of each template element together. These assemblies have clear advantages of reducing the fabrication cost and simplifying the physical construction due to the reuse of template elements.
In this thesis, we propose computational approaches to model different types of complex assemblies with discrete equivalence classes, aiming to maximize the reusability of template elements.
We first introduce two error-driven mesh optimization approaches to model masonry shell structures with a small set of template shell elements and wireframe meshes with a small set of template node and rod elements, respectively, where gaps and overlaps are minimized yet exist. To preserve the perfect contacts between instance elements, we adopt domain decomposition approaches to produce assemblies without gaps and overlaps, known as {\em tilings}. We propose a domain decomposition approach to create K-hedral tiling of 2D finite domains with the minimized number K of prototiles, called inverse tiling. We observe that directly generalizing our inverse tiling approach to 3D finite domains is not practical in terms of fabrication since either assemblability or structural stability cannot be ensured. To address these challenges, we present another domain decomposition approach to model high-level interlocking puzzles (i.e. a kind of 3D tilings) that require multiple moves to take out the first subassembly to avoid falling apart easily. We validate our computational approaches by fabricating a series of physical prototypes, demonstrating that our approaches have great potential to be applied for various assembly design problems ranging from small-scale such as puzzles and pixelized art to large-scale such as architectural rationalization.
... A third barrier emerges when it becomes necessary to use multiple tools that hardly interoperate with each other, increasing the propensity for information loss and error accumulation [12]. A last critical barrier is the time and effort needed to address manufacturing and cost-related constraints [13], especially when dealing with unconventional design solutions. All these obstacles make the integration of performance and manufacturing-related design variables incompatible with project deadlines and resources, hindering the development of more ambitious facade designs whose performance goes beyond minimum regulatory requirements. ...
... To make the construction of free-form shapes and complex facade patterns possible, architects have been increasingly adopting geometric optimization techniques [102] in their design practice. These strategies allow architects to gain more insight and control over their designs [40], facilitating the latter's gradual adaptation until reaching the desired feasibility [13]. Popular examples of geometric optimization strategies for architectural design include design rationalization and surface paneling. ...
... Design rationalization is an example of a geometric optimization strategy that focuses on subtly adjusting the building elements that are expensive to produce until meeting the established economic and construction requirements and without compromising the design's aesthetics [92,103]. Based on the literature [13,40,[104][105][106], design rationalization can vary in terms of temporal application in the design process, i.e., before, during, or after the design development process, and target of the rationalization process, i.e., the building elements to which it is applied, e.g., frames, facade panels, wall tiles, and shading devices. Fig. 6 presents some architectural examples resulting from the application of rationalization strategies at different design stages. ...
Buildings are a critical element of civilization, within which we spend over around 70% of our lifetime, but also one of the main contributors to the greenhouse effect. It is therefore important to ensure their design guarantees good indoor conditions, while minimizing the environmental footprint. Among the different building elements, the facade is one that most influences these two requisites and thus its design requires, in addition to the traditional aesthetic and functional requirements, the integration of performance criteria from early design stages. However, there are still some barriers to this integration, such as the limited flexibility of design tools, the need for multiple analysis and optimization tools, and their high computational cost. Recent computational design approaches, such as Algorithmic Design (AD), have been facilitating the combination of creative processes with the search for better performing and more sustainable design solutions. However, these approaches require programming skills, which most architects do not have. To maximize its potential for architectural design, efforts should be made to reduce the complexity of AD and approximate it to the architects’ design practice. We address this by proposing an AD methodology and algorithmic framework for facade design that encompasses its different stages, from conceptual design to manufacturing, and requirements, such as aesthetics, environmental performance, comfort, and costs, among others, while supporting the variability and diversity typical of architectural design problems. By combining the framework’s ready-to-use algorithms, multiple design scenarios can be considered, and various design requirements addressed, helping to achieve the goals established by both the 2030 Agenda and Industry 4.0.
... A key subject in this field is the use of parametric tools that can combine design, optimization, and fabrication of nonstandard geometry through variables, principles, and constraints [2,3]. These systems are often driven by various performance-based criteria ranging between material properties, structural behaviour, geometric optimization, or fabrication constraints [4]. As designers are tasked with developing optimal solutions for various structural, formal, or geometric problems, the development of computational workflows that can automate design and manufacture is becoming an area of growing interest [5]. ...
... Contemporary studies on form-finding design research present novel digital workflows where multiple parametric tools are integrated for the computational analysis and further design development of structures [4,5,15]. Fenu et al. revisited Musmeci and Nervi's historical structures, particularly concrete shell bridges to develop form-finding strategies combining particle-spring system and TNA implementing both vertical and horizontal forces to analyse structural behaviour under seismic loads [28]. ...
... A physical component of form-finding research is its applicability to materiality and the determination of digital fabrication tools and processes for the manufacture of parametric forms [6,8]. These often require developable surface strategies that can be manufactured out of planar elements or three-dimensional modular production, the former offering a cheaper solution, while the latter requiring custom formwork [4]. A surface-based strategy combining parametric, mathematical, and physical investigation into the characteristics of origami structures shows the advantage of rule-based principles using scissor units for deployment strategies [29]. ...
This article describes a parametric design and fabrication workflow influenced by Frei Otto’s form-finding experiments on soap films. The research investigates minimal surface geometry by combining physical and digital experiments in a computational framework. Operating on mesh topology, various parametric design tools and plug-ins in Rhinoceros/Grasshopper are presented to discuss the translation of minimal surfaces to flat strips suitable for planar fabrication using flexible materials. These tools are tested on a case study to show the automated design and manufacture of double-curved surfaces as double-layered strips running in perpendicular directions that can be affixed at point connections for structural stability. The development of the parametric workflow, material constraints, and stripped fabrication of layers are discussed.
... Originally, the profession of architecture involved both tasks and, thus design decisions were highly dependent on the construction viability of the solutions [330]. It was the architect who made the relationship between design, structure, and materiality, as it is visible in ancient iconic buildings such as Egyptian pyramids, Greek temples, and Gothic cathedrals [331]. The separation of architecture and construction occurred during the Renaissance period, when architects started to differentiate themselves from master builders and craftsmen [330] by focusing more on the ideation and design development processes rather than on solving construction issues [332]. ...
... In the last decades, the design freedom allowed by most CD technologies has been motivating the design of more complex freeform shapes [69], as well as the creation of intricate facade design patterns. Unfortunately, their production is often challenging and expensive and, in many cases, the complexity achieved can be hardly conceived through traditional construction methods [331,335]. ...
... As a result, architects have to spend a lot of time and effort in solving manufacturing and economic issues [331] and it is often the case that their creative intent is neglected in favor to these. ...
Architecture has always explored the latest technological advances in terms of design representation and production. Nowadays, Algorithmic Design (AD) approaches play a critical role in the conception and production of architectural solutions, overcoming many of the practice’s limitations in solving more complex design problems, such as those of facade design. Nevertheless, AD is a complex design approach that requires programming skills and deviates from the visual nature of architecture. This research addresses this problem by focusing on the field of facade design, proposing a methodology and framework that reduces the complexity of AD in solving complex facade design problems.
To that end, the thesis examines recurrent problems and strategies in facade design, identifying the existing design patterns, formulating their underlying principles, and organizing them in a categorical way. To generalize the proposal and facilitate its application in different design practices and briefs, the thesis adopts a mathematical approach and organizes the formulated principles in a modular way. Since the aim is to support design-to-fabrication AD workflows, it is important to ensure the adaptability of the proposal to the context-specificity and variability of architectural practice, as well as to the various methods and tools used.
To assess the proposal’s validity and accuracy, the mathematical methodology is implemented in the algorithmic framework DrAFT 2.0 and is used to reproduce an existing set of building facades. Then, to evaluate the proposal’s applicability and usefulness for architectural practice, the framework is applied in a set of application studies involving architects with different AD skills and responding to various design intents and problems. After reflecting on the research findings, the thesis concludes that the proposal simplifies AD, increasing the flexibility and efficiency of facade design processes and thus the design space considered. It also demonstrates how the proposal enhances creative and critical thinking processes, increasing the likelihood of achieving better solutions.
... Another critical change was enabling the automation of manufacturing processes, making it possible to materialize the design freedom allowed by CD tools accurately and with acceptable time and effort. The emergence of Digital Fabrication (DF) tools made the production of unique building elements more accessible, partially solving the lack of flexibility of traditional construction methods [2]. As a result, the architectural production of the last decades also changed, especially regarding the design of building facades, motivating the development of unique building shapes and geometric patterns that simultaneously respond to multiple requirements. ...
... The architect had a central role in the entire process, not only establishing the relationship between design, structure, and materiality, but also managing the available materials and construction techniques and their associated costs. This is visible in ancient iconic buildings such as Egyptian pyramids, Greek temples, and Gothic cathedrals [2]. The separation of architecture and construction occurred during the Renaissance period, where architects started to differentiate themselves from master builders and craftsmen [14,15]. ...
... Unfortunately, the design freedom allowed by CD tools is often constrained by the lack of flexibility of most construction methods [2]. Although the available DF strategies are gradually changing this reality, they still present limitations that hinder their widespread use [16]. ...
Two main concerns drive the architectural practice: the design and the construction of buildings. This makes the creative practice highly dependent on construction viability, most design decisions having to consider, among others, the available materials and construction techniques and the associated manufacturing costs. Nevertheless, the desire to conceive complex geometries has always been present in architecture, often leading to innovative solutions and structures that go beyond what had been done to date. The emergence of computational design in the last decades has further accentuated this ambition by providing architects with unprecedented design freedom. The realization of such shapes, however, is not as easy as its 3D modeling due to limitations in the available manufacturing strategies. In this paper, we address this problem with Algorithm Design (AD), a design approach based on algorithms, presenting a design workflow that benefits from its (1) geometric freedom in developing facade design solutions and (2) expressiveness in converting and detailing the obtained solutions for manufacturing. We evaluate our proposal with an algorithmically developed prototype of a geometrically complex facade. The aim is to illustrate its potential in exploring design alternatives that consider multiple design criteria, while automatically detailing them for construction and producing the corresponding technical documentation. We also intend to demonstrate the importance of the proposal’s flexibility in considering different construction schemes that, in turn, result in different aesthetic outcomes and manufacturing needs.KeywordsAlgorithmic designFacade designDesign-to-FabricationDesign workflow
... This critical step in digital fabrication techniques for intricate geometries addresses fabrication and material constraints. Geometry rationalisation, after two decades of exploration, has been further categorised into five specific methods within the general framework of pre-, co-and post-rationalisation by Austern, et al. [15]. Pre-rationalisation includes fabrication-driven design, guided by a specific fabrication technique, and fabrication-aware form-finding, using algorithms for feasible designs. ...
... In addition, parametric co-rationalisation provides continuous design feedback as the geometric design and prototyping fabrication are conducted interactively. Austern et al.'s [15] classifications, this paper investigates the appropriate timing and methods for integrating designers' considerations into these processes (Fig. 1). ...
This paper explores the integration challenges of advanced parametric modelling techniques and architectural-scale concrete façade fabrication technologies. Despite concrete's versatility and durability, which make it a preferred material for parametric façade designs, a nuanced comprehensive understanding of balancing its geometric variability and viability is absent. This review investigates the interplay among digital geometric design and fabrication techniques, shedding light on design strategies regarding fabrication constraints and the limitations of current design approaches. By categorising design methods in concrete façade design and production, it underscores the importance of fabrication-informed para-metric design strategies. The paper reviews recent research on geometry types and related design approaches. It concludes by highlighting the strength and potentials of balancing geometric variability and viability in the parametric context, which has implications for the future design and construction of concrete architectural elements.
... However, some of these shapes have proven to be difficult and expensive to realize, even using state-of-the-art digital fabrication processes. 5 Among the many types of free-form surfaces, developable surfaces are increasingly adopted in contemporary architecture. This mainly relies on their resource-efficient and digital fabrication-oriented properties 6 ; that is, their components (panels) can be manufactured via computer-numerical-controlled (CNC) fabrication processes with the minimal material loss. ...
... The intersection angles φ ij are invariant from their initial values during Ricci flow. Step 0: From the given initial geometry of a discrete surface, compute the member lengths l ij using Equation (5), and estimate the circle radii r i using Equation (8). Scale the radii r i for all nodes as in Equation (9) by the coefficient α obtained from Equation (12), and compute the intersection angles φ ij by Equation (13). ...
This paper presents an approach for the design of discrete architectural surfaces that are globally developable; that is, having zero Gaussian curvature at every interior node. This kind of architectural surface is particularly suitable for fast fabrication at a low cost, since their curved geometry can be developed into a plane. This highly non‐linear design problem is broken down into two sub‐problems: (1) find the member lengths of a triangular mesh that lead to zero Gaussian curvature, by employing the discrete surface Ricci flow developed in the field of discrete differential geometry; (2) realize the final geometry by solving an optimization problem, subject to the constraints on member lengths as well as the given boundary. It is demonstrated by the numerical examples that both of these two sub‐problems can be solved with small computational costs and sufficient accuracy. In addition, the Ricci flow algorithm has an attractive feature—the final design is conformal to the initial one. Conformality could result in higher structural performance, because the shape of each panel is kept as close as possible to its initial design, suppressing possible distortion of the panels. This paper further presents an improved circle packing scheme implemented in the discrete surface Ricci flow to achieve better conformality, while keeping its simplicity in algorithm implementation as in the existing Thurston's scheme .
... However, free-form surfaces are typically complex due to the inherent double curvature, which often poses great difficulty for real-world construction. Therefore, in the last decade, significant effort has been focused on the problem of architectural rationalization, i.e., making the construction of complex surfaces feasible and affordable [4][5][6][7][8]. ...
... 3. Calculate the distance from each face to the updated centroid. 4. Check if the current group number reaches the target value. ...
Free-form structures are highly valued for their aesthetic appeal in architecture, but they typically comprise panels of many different shapes, which can pose great challenges for building construction. In this study, we aim to address this issue by proposing a novel clustering–optimization method to reduce the number of different 𝑛-gonal faces in free-form surface approximations. The method partitions the faces into several groups of similar shapes through clustering and transforms the ones within each group toward congruent forms through optimization. By utilizing this approach, the number of geometrically different panels can be reduced while also satisfying a user-specified error threshold. The potential practical application of this method is demonstrated by redesigning the façade of a real architectural project to achieve cost-effective solutions.
... The rationalization of non-standard architecture is well established in practice and is still an active research topic in academia. Practical restrictions results from the machining tool capabilities, which are more difficult to express as geometrical constraints (Austern et al. 2018). These limitations are rarely included in the early stages of design or in scholarly studies dealing with fabrication-aware design, resulting in a gap between design workflow and production. ...
... Conversely, with ROD being mainly focused on industrialization and mass production, few works on architectural geometry have been integrated into this workflow. Therefore, finding a compromise between a ROD approach and advanced geometrical principles for construction rationalization is still a vastly open research route, as pointed out by Austern et al. (2018). ...
This article investigates the application of a multi-robotic platform to the fabrication of complex “free-form” timber structures. A concept of “smart factory”, with a 13-DOF robotic cell combining robotic mobility with fixed workstations, is proposed. A computational workflow was implemented to allow for fast iterations during the early design stage. The robotic cell design and design workflow are implemented in practical experiments conducted in the framework of intensive workshops. A productivity assessment is performed on a 50 m2 pavilion pre-fabricated with the proposed robotic cell.
... The initial architectural sketch almost always undergoes rationalization to reach constructability, particularly when the building will be manufactured (for example, the design of the Sydney Opera House). Austern et al. (2018) find that rationalization for efficient manufacturing is done in only 35 per cent of the studied projects before the design development project stage. They proposed a taxonomy for rationalization strategies, which include the following: fabrication constraints, material constraints, construction constraints and design constraints. ...
... The various design scenarios and fabrication processes are heavily dependent on the type of CNC machine and also on the material (as shown in Table 3 in Austern et al., 2018). Automated fabrication creates a strong potential for product individualization when the model is directly connected to the manufacturing machine. ...
... Several review articles have investigated 3D printing in construction. Currently, wood, steel, polymers, and concrete are the most commonly used materials in 3D-printed projects [30]. Polymers are the least common among them, and their use in the construction of structural components is limited due to their high production costs and low rigidity [31]. ...
... Polymers are the least common among them, and their use in the construction of structural components is limited due to their high production costs and low rigidity [31]. Concrete and cement-based materials have been progressively used in digital production techniques in the past 5-10 years, in addition to wood and steel [30]. Bedarf et al. [32] reviewed the area of foam 3D printing in construction and determined an outline of relevant developments. ...
3-dimensional (3D) printing technology, a core technology of Industry 4.0, is increasingly being applied in the construction industry. Scientific research and deployment of this technology in the building industry have both significantly contributed to its widespread use. The aim of this research is to evaluate the material used in 3D printing technologies in the construction sector to understand its development and future research in the industry and scientific community. The evaluation included 74 research publications from the Web of Science database and 25 building applications from the construction sector. The VOSviewer and Bibliometrix package for R software were used to visualize the results of the bibliometric analysis graphically. The literature was examined and it was found that cement-based materials, polymer, concrete, recycled or waste materials, and new material mixtures are being investigated, with concrete receiving the most attention. The 25 3D-printed constructions were predominantly houses (76%), and these construction printing materials primarily used concrete (88%). 3D printing material design mixes must provide rheological properties such as printability, extrudability, and manufacturability. The properties of materials used in 3D printing, such as fire resistance, durability, thermal properties, and acoustics, are examined in very few studies. However, further research should characterize and improve the material properties associated with 3D printing buildings.
... In order to understand the choice and implementation of the method for multi-functional optimization the properties of the RSM have to be introduced [39]. This method represents a group of mathematical and statistical techniques that define the relationships between the response (result that we are looking for) and independent variables (input parameters that influence the result). ...
... For the method to succeed, it is necessary to determine optimal settings (ranges of values) and input parameters that can result in a maximum (or minimum) response over a certain region of interest, R [39]. The better the choice of input parameters of the model, the greater the chance to determine the value of the optimum [40]. ...
Although they are very efficient structures, concrete shells have lost popularity due to the complexity of the traditional construction process using cast-in-place concrete. A key concept to overcome the labor-intensive formwork in situ is the segmentation of the shells into prefabricated parts. In order to avoid individual formworks during prefabrication as well, the authors rely on extrusion-based 3D printing of strain-hardening cement-based composite (SHCC). The goal is a highly automated, scalable, and adaptable flow-prefabrication of modules controlled by a holistic digital design process. Such the creation of modular free-form shell structures can be accelerated significantly, resulting in structures comparable with gridshells. Starting with the problem statement and the elaboration of the technology used, the main contribution of this research is the development of geometrical methods for modularization based on given production conditions. The challenge lies in the free-form geometry discretization with respect to the structural analysis and within the defined constraints such as planar quads, no edge torsion, and minimal material consumption. Methods of discrete differential geometry for circular PQ (planar quad) mesh generation are combined with Response Surface Methodology (RSM) for multi-objective optimization of the global parameterized shape. The results were illustrated in a study case where the geometrical and structural production parameters of starting and final shell are compared.
... Rationalization has been widely used since architects started designing complex, double curved geometries around the turn of the millennium (Fischer, 2012;Pottmann et al., 2015). A recent review of rationalization methods in current architectural projects indicated that the computational optimization of a geometry to better suit a fabrication technique is a widely used rationalization method, especially for free form geometry (Austern et al., 2018). The use of optimization for rationalizing geometry is described in the back-ground section of this paper. ...
... In this type of rationalization process, the initial design is arrived at without taking specific fabrication constraints into consideration. Later, an optimization algorithm is used to explore the design space and change the geometry to better fit a fabrication technique (Austern et al., 2018). An example of this type of process is shown by Vaudeville et al. (2013), who describe how the glazing of the Foundation Louis Vuitton was optimized to suit the fabrication constraints of the rolling and bending techniques used to form them. Similarly Schiftner et al. (2013) describe how the facade panels of the Eiffel pavilions were optimized according to the glazing fabrication constraints. ...
... The function of the segmentation algorithm goes bottom-up which means that the initial goal is not to approach arbitrary starting shape idea, which is usually done when starting with already defined design that can be in a form of NURBS surface [22]. The goal is to find the right approach within formulated design idea for printa-ble modules with enough freedom in designing shape, with the intention to create better rationalization strategies used in design sequence and their relation to digital fabrication processes [23]. This is achieved by using curves as an input parameter, generating discretized surface, then comparing the resulted PQ mesh system with Rhino/Grasshopper modelling. ...
... In order for the method to be the most successful, it is necessary to determine the optimum settings (ranges of values) and input parameters so that they can result in a maximum (or minimum) response over a certain region of interest, R [23]. The better is the representation of the input parameters of the model; the bigger chance is to determine the value of the optimum [24]. ...
Shell-like, double curved and thus above-average performance structures, are usually produced monolithically on site. For industrial advancement, however, they must be divided into transportable modules which can be assembled on the construction site (design for assembly). Models are lattice shells made of steel and glass, in which predominantly flat sub-surfaces (modules) are used. Therefore, the main question is: Which modularizations are suitable for flow production with mineral building materials? In this paper designed free-form surface is going to be discretized as PQ circular mesh system, suitable modules for 3D concrete printing. Moreover, the multi-criteria optimization is done with Response Surface Methodology (RSM) in order to get optimal final shape. The goal is to start from the arbitrary shape, that can be generated from two curves, with possible two-way division into modules and compare it with the resulted discretized PQ circular mesh system, realized with new algorithm. The comparison can be defined through two main criteria: geometrical and structural.
... These structures are truss-like constructions composed of interlocking lightweight elements arranged in specific geometric patterns, typically used to span large areas with minimal supporting columns. Space structures are particularly favored in architectural applications due to their excellent structural performance and esthetic appeal, especially in free-form configurations [2][3][4][5]. Despite extensive research on specific aspects of double-layer grids, the literature lacks comprehensive comparisons that evaluate the structural performance of these grids across various constitutive units, structural depths, and cross-section diameters. ...
This paper investigates the structural performance of flat double-layer grids with various constitutive units, addressing a notable gap in the literature on diverse geometries. Six common types of flat double-layer grids are selected to provide a comprehensive comparison to understand their structural performance. Parametric models are built using Rhino and Grasshopper plugins. Single- and multi-objective optimization processes are conducted on the considered models to evaluate structural mass and maximum deflection. The number of constitutive units, the structural depth, and the cross-section diameter of the members are selected as design variables. The analysis reveals that the semi-octahedron upon square-grid configuration excels in minimizing structural mass and deflection. Furthermore, models lacking a full pyramid form exhibit higher deflections. Sensitivity analyses disclose the critical influence of the design variables, particularly highlighting the sensitivity of structural mass to the number of constitutive units and cross-section diameter. These findings offer valuable insights and practical design considerations for optimizing double-layer grid space structures.
... These surfaces, however, are inherently complex due to the double curvature, which often poses great difficulty for real-world construction. To address this, significant effort has been focused on the problem of architectural rationalization, aiming to make the construction of complex surfaces feasible and affordable [2,3]. ...
Free-form surfaces are increasingly used in architectural designs for their striking aesthetic appeal. While they can be assembled from prefabricated simple polygonal panels, this process is typically challenging and costly due to the need for many different panel shapes. To address this, we present an innovative design method that can approximate free-form surfaces using a single type of regular (or near-regular) triangle. The method starts with an initial triangle and gradually 'grows' new ones until the target surface is entirely covered. During the growth process, the method strategically assigns the locally optimal valence to each vertex to accommodate the surface curvature. Vertex positions are dynamically updated to keep triangles as equilateral as possible and aligned with the target surface, through an efficient localized optimization process. Tested on multiple numerical examples, the method can solve both complex organic shapes and architectural surfaces with open boundaries. The resulting mesh features seamlessly connected, near-regular triangles and smooth patterns with a small number of singularities. Via best-fit matching, each triangle can be replaced by a standard regular triangle (or the mean shape) to generate exactly congruent panels with small gaps, potentially enabling realistic manufacturing and assembly.
... Finally, in post-rationalization, information about the structure, materials, fabrication setup, and construction sequence gets involved to create a new informative digital model. The complexity of this process is to preserve the design intent ( Fig. 4) Austern et al. (2018). ...
... O estudo iniciou com uma revisão sistemática, a partir de palavras-chave pesquisadas em um repositório da área, organizando as informações em categorias para gerar um subtrato novo (Austern et al., 2018). Desse modo, foram selecionados artigos publicados por autores atuantes na América do Sul, nos dois congressos de maior inserção de suas publicações na área, o SIGraDi e o eCAADe, entre 2000 e 2021. ...
The main objective of this article is to grasp how technologies, techniques, and concepts related to Digital Fabrication were applied by South American players, in academic production from 2000 to 2021, through pedagogical activities, design projects, manufacturing processes, prototypes, and artifacts. We conducted a systematic review of publications from SIGraDi and eCAADe conferences, by authors active in South America during the period, identified from the CumInCAD database using the following terms: digital fabrication, digital manufacturing, digital fabrication, digital fabrication, rapid prototyping, CAD/CAM, robot* and 3d print*. 260 articles met the final criteria for inclusion, organized from the combination of 10 categories. The results show the dissemination of information about digital fabrication in many countries, focused on different trends of research and innovation, allowing us to understand the evolution of technological appropriation, thus offering an in-depth overview of our situation over the past 20 years.
... Despite their aesthetic appeal, the inherent complexity of these curved surfaces poses significant construction challenges, often leading to high construction costs [2], especially due to specialized labour and materials [3]. One cost-effective solution is to employ discrete 'curved surface approximations'-a technique that rationalizes target curved surfaces using many simple, planar or non-planar (slightly curved), polygonal panels [4], as seen in numerous iconic buildings [5]. However, studies on construction cost and time reveal that free-form buildings, including curved surface approximations, usually exceed their budgets significantly due to the use of disposable moulds for producing required panels [6]. ...
Curved surfaces may be approximated using polygonal panels to simplify complex architectural designs, yet their constructions can be expensive due to single-use moulds producing unique panels. To reduce costs, strategies like planarizing and reducing the number of different panels have been suggested, which are
increasingly achievable with advancing digital fabrication technologies. However, current subtractive and additive manufacturing techniques face challenges in producing complex 3D shapes and large volumes, respectively. Combining these two techniques has been attempted, mainly with small 3D-printed nodes, leaving the direct realization of curved surface approximations unexplored. This paper extends the thick-panel origami theory to introduce planar-thick panels and 3D-printed gap fillers for cost-effective constructions. It presents a
computational workflow to transform meshes into non-intersecting panels while preserving edge connectivity and frame-like gap fillers with minimized volumes. Physical prototypes demonstrate significant cost savings compared to direct 3D printing. All prototypes are accurate within a 10 mm material thickness due to the guidance of the gap fillers. The finite element analysis shows that structural performance is greatly influenced
by the material properties, especially of panels, due to their relatively larger volume. Numerical examples are also presented using the 𝑘-means clustering-optimization method to reduce the number of different panels.
... Other contributions include variables of different nature in the objective function or in the constraints, such as aesthetics and buildability. In the last decades, a significant effort has been spent on rationalizing free-form structures to achieve feasible construction with reduced manufacturing costs [31][32][33][34] eventually modifying the connectivity [35]. Other papers propose optimization methods to achieve developable surfaces [36,37] or meshes composed of planar elements [38][39][40], including repeated elements [41] or meshes with no torsion on the nodes [42]. ...
... The segmentation of complex geometries has been widely researched [18]. A common application is the segmentation of timber [19][20][21][22][23], masonry [24], or steel shells [25] into flat polygonal shapes that can be prefabricated and assembled on site. ...
Modular floor slabs must be subdivided into prefabricable, transportable segments. This slab segmentation process conventionally uses a rectangular pattern, particularly for timber buildings. Regular segmentation patterns and strict column grids are ideal for rectangular building shapes, but restrict timber buildings to only some architectural uses, and are unideal for urban infill. Unfortunately, planning and constructing multi-storey wood buildings without a strict grid is still challenging. There is therefore a conflict between the desired column placement and the constraints imposed by building systems. This article investigates novel methods for segmenting timber floors supported by irregular column layouts. It proposes six different segmentation methods that are informed through Co-Design by structural, material waste, and transportation requirements. Co-Design allows for the direct integration and automated feedback of such diverse criteria into the early building design phase. These methods are based on three well-known computational approaches: Single-Objective Optimisation, Parametric Modelling, and Agent-Based Modelling. They could also be applied to other non-timber prefabricated floor systems. The segmentation methods are demonstrated on two example floor slabs with irregular column layouts, one with a rectilinear and the other with an irregular outline. The methods are compared using quantitative proxies for cost, fabrication time, architectural adaptability, and assembly complexity. More benchmark testing is needed, but initial results showed that the most efficient segmentations cannot adapt to irregular layouts, emphasising the need for a more adaptable approach to modular timber construction.
... Previous related work investigates design knowledge [Woodbury, 2010;Oxman, 2017] and pedagogical aspects of parametric design [Bacinoglu & Alacam, 2014], and the role of visual programming and scripting languages [Aish & Hanna, 2017;Celani & Vaz, 2012]. We reference further related work on digital workflows [Wortmann & Tunçer, 2017], design for manufacture and assembly [Austern, 2018], and multi-criteria design [Imbert, et al., 2012]. ...
... Instead of directly reusing the polygons, other works aim to reuse molds that are used to fabricate curved panel elements [Eigensatz et al. 2010] or triangle-based point-folding elements [Zimmer et al. 2012], in which elements of the same shape are fabricated with molding and then cut into di erent sizes and forms for making the architectural surface. The above works optimize speci c discrete equivalence classes for di erent input surfaces, a process known as post-rationalization [Austern et al. 2018]. In contrast, Liu et al. [2021] addressed the pre-rationalization problem of modeling various input surfaces using prede ned discrete equivalence classes of triangles by developing a fabrication-error-driven remeshing algorithm. ...
This paper proposes a method to model masonry shell structures where the shell elements fall into a set of discrete equivalence classes. Such shell structure can reduce the fabrication cost and simplify the physical construction due to reuse of a few template shell elements. Given a freeform surface, our goal is to generate a small set of template shell elements that can be reused to produce a seamless and buildable structure that closely resembles the surface. The major technical challenge in this process is balancing the desire for high reusability of template elements with the need for a seamless and buildable final structure. To address the challenge, we define three error metrics to measure the seamlessness and buildability of shell structures made from discrete equivalence classes and develop a hierarchical cluster-and-optimize approach to generate a small set of template elements that produce a structure closely approximating the surface with low error metrics. We demonstrate the feasibility of our approach on various freeform surfaces and geometric patterns, and validate buildability of our results with four physical prototypes. Code and data of this paper are at https://github.com/Linsanity81/TileableShell.
... A detailed description of manufactured structures is important because their shapes do not conform to known forms as defined by biological evolution or previous use. Such structures can assume a much broader range of forms targeting, for example, the ease of deployment, reusability, adaptability, space-filling capacity, or other useful attributes [40,41]. Computer-aided design can optimise such structures automatically but needs explicit criteria and comparative methods for implementation. ...
The need to support life in degraded landscapes is a pressing challenge of our time. Models from ecology, computing, architecture, and engineering can support the design and construction of habitat features in contexts where human intervention is necessary and urgent. For example, anthropogenic change is causing many arboreal habitats to disappear due to diminishing populations of large old trees. Current management approaches can provide artificial replacements in the shape of poles for perching and boxes for nesting. However, their large-scale long-term impacts are rarely assessed and often unclear. Along with benefits, these structures can result in ecological traps, waste, and pollution. Although computer-aided design and fabrication can provide more sophisticated solutions, limited understanding of tree structures and their use by arboreal wildlife constrain the formulation of clear goals for engineering. In response, this research examines long-term implications at a restoration site that already features a variety of living and manufactured habitat structures. To do so, we build a computational simulation that uses high-fidelity lidar scans of trees in combination with field observations of bird interactions with branches. This simulation models landscape-scale dynamics of habitat supply over hundreds of years. It can account for many types of structures, including trees, snags, and utility poles, irrespective of the processes that led to their availability. We use this understanding of integrated supply to generate quantitative comparisons of design strategies that can inform design decisions in application to arboreal habitats and other modified ecosystems.
... However, free-form structures, characterized by their complex doublycurved geometries, are often extremely difficult and costly to realize in reality. Therefore, in the last decade, significant effort has been focused on rationalizing free-form structures to achieve feasible construction with reduced manufacturing costs [2][3][4]. ...
Space frame structures are increasingly adopted in contemporary free-form architectural designs due to their elegant appearance and excellent structural performance. However, a space frame structure in a doubly-curved form typically comprises nodes of different shapes. This often requires extensive node customization, hence incurring high manufacturing costs. In this study, we propose a new clustering-optimization framework to reduce the number of different nodes in space frame structures. In clustering, nodes are divided into different groups, with similar shapes grouped together, using an enhanced-means clustering technique. In optimization, nodes within the same group are transformed towards congruence while closely approximating the target surface. Together, by interleaving clustering and optimization, our method can minimize the node shape variety under a user-defined error threshold. The effectiveness of the method is validated through a variety of numerical examples. The potential practical application of our method is demonstrated by redesigning a complex, free-form architectural project.
... A comprehensive review on rationalization (Austern, Capeluto, and Grobman 2018a) demonstrated that one of the main problems caused by relying on fabricators to rationalize projects is that the typical bid procedure introduces them relatively late. At this stage, the design has been finalized and tendered (Celento 2010) making it difficult to effect significant changes in the building geometry as various other systems have already been designed (MacLeamy 2004). ...
This paper presents a framework for an analysis method and computational tool, which evaluates the fabrication parameters of complex geometries. The suggested method predicts the feasibility, material use, and machining time required for fabricating the moulds for these geometries. It achieves this by interrogating geometric properties instead of the traditional machining simulations. Using the algorithms developed in this research, the method can provide real time evaluation of computer-controlled mould fabrication techniques such as cutting and assembling sheet materials, multi-axis milling of volumetric material, and robotic hot wire cutting. In the paper, we describe the mathematical basis of the suggested method. We demonstrate how the method provides real-time visual feedback for designers and allows them to adjust their design according to fabrication constraints in the early design stages. Using architectural case studies, we show how the analysis results provide precise cost estimates and help minimize fabrication resources in manual or automatic fabrication optimization processes.
... The ability to generate practically any imaginable form with ease on the computer screen, with digital design tools and advanced visualisation capacities, has led to the ongoing rising challenge of its materialisation as built structures. For over two decades, the realisation of complex and curved geometries has represented a major ongoing challenge for architects and builders alike (Kolarevic [1]) (Austern et al. [2]). The large scale of the architectural object and the extensive reliance on moulds in the construction process, accentuate the barriers and limitations raised by issues of cost and sustainability (Hickert [3]). ...
In recent years, architects and engineers are seeking for alternative formation processes, as part of a general effort towards a more sustainable materialisation of complex geometries. Form and structure are developed based on the generative power of material, which is no longer regarded as passive or ideally inert and stress free. A parallel revolution in the way in which solids are described and manipulated in the field of non-linear physics, has led to new understanding of spontaneous material formations.
Learning from nature, the theory of incompatible sheets was developed to describe the emergence of form and motion from intrinsic material properties through stress induced processes. Geometrical incompatibilities are prescribed in the material, making a flat ‘Frustrated Material’ that spontaneously configures itself into a predictable complex 3D shape. So far, realisations of self-shaping by material incompatibility were reduced in scale limited to delicate lab-materials. In this research we develop new
frustrated materials in flexible membranes, ceramics and FRP, that can relate to an architectural scale.
We demonstrate the application of principles of incompatible sheets in three frustrated materials, and show how 2D material construction self-shapes into complex shapes, opening new morphological horizons for future architectural formation processes.
... With the developing use of VR, this gap seems to be lessening. c) Measurement of the variable of space geometry -is lacking (Nanda, Pati, & McCurry, 2009), as parametric design is comparatively new, and most of the literature emphasizes parametric design in studies associated with the quantification of geometry in architectural applications related to new technologies of construction (Austern, Capeluto, & Grobman, 2018;Weizmann, Amir, & Grobman, 2016). 3. The possibility of using the results in an architectural design process Ilozor and King (1998) point out that aesthetics is given little or no attention in building project evaluation. ...
In this paper, a multidisciplinary approach to examining the connection between visual perception, human emotions and architectural space is presented. It details a study in which emotional reactions to architectural space geometry are empirically measured and quantified. Using various sensors, including EEG (Electroencephalography), GSR (Galvanic Skin Response), and eye-tracking (ET), we collected data from 112 individuals experiencing virtual environments (VEs), characterized by a variance of geometric manipulations. Diffusion map algorithms, as well as other statistical methods were used to analyze the data. Findings suggest that criteria of protrusion, curvature, scale and proportion of space influence the user's emotional state. Indices of ET, GSR, electrical brain activity, as well as dwelling duration and self-report liking ranks, show both “negative” and “positive” interest changes.
Impact statement
This research examined the connection between the properties of space and human emotions by means of empiric measurements of emotional affect, generated by changes in the geometry of space, related to the criteria of protrusion, curvature, scale and proportion. Results demonstrated that changing the geometric properties of architectural space is significantly associated with a significant effect on human emotions. This indicates that emotional responses generated by architectural spaces can be empirically measured and quantified. Implications for residential, education, and rehabilitation settings are evidenced.
... Modularization and post-rationalization of freeform surfaces is a common task in architecture and engineering. 41 While surface-based approaches have proven to be a feasible input for the segmentation of freeform geometries into planar elements of constant cross-section, 42 they are unable to address the problem of translating the volume they describe into space-filling solid modules. Figure 8 shows three basic approaches on how to decompose any kind of solid geometry into smaller elements. ...
The pursuit for more load‐adapted, individualized, and at the same time precise building geometries is driving innovation in digital fabrication with concrete towards greater formal freedom and higher degrees of prefabrication. This paper reviews the opportunities of using 3D‐Printed formwork in the context of pre‐fabricated concrete construction. It identifies the geometric specificities future planning tools need to address in order to incorporate the steps of modularization and fabrication into automatized planning processes from design to production. By reviewing the state‐of‐the‐art fabrication methods for non‐standard concrete geometries, we highlight possible applications and challenges for additive formwork and introduce a volumetric modeling approach to modularize surface and mesh‐based 3d design models into solid segments that can form the basis for further formwork planning.
... The control algorithm is based on the Grasshopper platform, a parametric design tool widely used in digital fabrication [29]. Grasshopper is a highly versatile platform that can integrate manual and automatic design strategies in different stages. ...
Extrusion-based 3D concrete printing (3DCP) is one of the most widely used methods for the digital fabrication of concrete material. For variable thickness components, inner cavity or internal toolpath can occur when using constant-width filament. Printing with variable-width filament is a possible solution to reduce the inner toolpath and enhance the integrity of the components. However, the conventional open-loop control method requires pre-calibration of materials and extrusion equipment and relies on the fine control of the material properties and the stability of the pump system. This paper presents a variable-width 3DCP method using real-time toolpath planning and extrusion control (RTPEC). In this paper, the material requirement, extrusion system, and real-time control algorithm are discussed. A controlled experiment is performed to verify the feasibility of the algorithms and the real-time control system. The printing accuracy in the horizontal and vertical directions is analyzed by 3D scanning. The result shows better horizontal accuracy and surface quality by using the RTPEC method. The result is well within the tolerance of the building scale component and demonstrates the potential applications in 3D concrete printing of building scale components.
Parametric architecture has played a vital role in architectural design in recent times. Research on early form-finding of architectural forms represents a notable area of study. Despite the significance of energy performance, digital fabrication, and aesthetics as design objectives, there is a lack of a comprehensive framework that integrates them in the form-finding process. To address this gap, this research conducts a systematic review of previous studies on form-finding and optimization of architectural forms, focusing on the three aforementioned objectives. Then, based on the analysis of the selected studies, the research proposes a multi-objective optimization framework for form-finding of architectural parametric forms, considering energy performance, digital fabrication, and aesthetics. The framework comprises five phases: form generation, multi-objective optimization, aesthetic evaluation, geometry rationalization, and digital fabrication of a prototype. This framework is usable by any architect, regardless of their programming knowledge, and is applicable to any new architectural design.
Layout design is a complex problem requiring significant expertise and considerable effort. Digital tools and Generative Design (GD) concepts provide opportunities for improving and automating the layout design process. However, the adoption of GD concepts in practice still needs to be improved. Hence, case studies where GD has been used in practice can offer critical insights into GD implementation. This research presents the findings from the SWOT (Strengths-Weaknesses-Opportunities-Threats) analysis of such a case study. The industry commissioned the researchers to develop a GD tool for layout design optioneering for paper mills. Thus, the findings are based on action research, which provided the authors with first-hand insights into the practical challenges and opportunities for GD implementation in industrial facility layout problems (FLP). Findings suggest that the objectives and technical rules governing industrial layouts make a strong case for GD implementations. However, the lack of established digital workflow, the need for GD expertise and experience within client teams, and the lack of GD best practices are the major threats and weaknesses limiting GD adoption and implementation. Based on the findings, implications for GD research and practice are discussed.
The construction industry has a massive impact on climate change, and reducing its environmental impact is a critical challenge that requires innovative solutions. Shape and topology optimization methods can play a crucial role in addressing this issue by optimizing the structural geometry and material distribution. In this paper, we present a novel design approach for optimizing shape, topology, global warming potential and buildability. The proposed approach optimizes the shape and layout of structural elements to minimize the overall embodied energy and carbon emissions of the structure while ensuring that the structure is constructible. The methodology is demonstrated through case studies, the optimized design is evaluated based on the performance criteria and constraints that resulting in significant reduction of design cycle time as well as environmental impact while improving buildability. The research presented in this paper provides valuable insights for designers and engineers seeking to create environmentally sustainable yet elegant spatial structures with optimal buildability.
A computational approach for free-curved reinforced concrete (RC) shells that simultaneously considers structural performance and associated construction strategy is proposed. First, for the rapid design and construction process, a unit–formwork construction system (UFS), which uses multiple construction methods dependent on curvature, is developed, and a mock-up test is conducted to validate its effectiveness of UFS. Although the construction time was reduced, the construction costs were confirmed to be approximately twice those of conventional methods. Furthermore, the error between the measured surface coordinates of the plywood form board (PFB) and corresponding three-dimensional (3D) data is computed, and the study confirmed that the error in construction was within half of the required level. Second, a multi-objective optimization problem is formulated to obtain a shell configuration and a suitable distribution of curvatures on the PFB by minimizing the squared normal curvatures of a PFB surface and the strain energy of the completed shell structure under distributed loads. To assess the manufacturability of PFB, the normal curvatures on the surface of the PFB, which are represented as quadrilateral meshes, are calculated. Finally, numerical examples demonstrate the efficiency of the proposed method for designing a free-curved RC shell from the perspectives of structural design and constructability.
Systems of structural spatial steel floor structures were considered. The purpose of the article is the improvement and rationalization of the new steel spatial structure and the possibility of its use for overlapping plans of complex geometry. The analysis and rationalization considered in this publication of the structure was carried out on the basis of the bioenergetic method. The application of the bioenergetic (BEO) method involves the construction of an energy portrait of the structure, that is, the analysis of the fields of the density of the potential energy of deformation and the analysis of the transformation of the potential energy of the deformation itself, when the external parameters are changed. Using the BEO method, on the example of the analysis and comparison of a triangular and rectangular structure, with the same overlapping area, with the same bearing conditions and with the same consumption of steel, a more effective design scheme was selected. The scientific novelty is the confirmation of the effectiveness of building the energy portrait of the structure and the rationalization of its parameters, as well as the principles of building and solving the problem of direct design (optimization) of a spatial rod structure, which has a priori positive characteristics. The practical significance of this work is that the construction in question has highly competitive technical and economic indicators, which are significantly different from known systems, which is confirmed by the comparisons presented in the publication. This structural system has already found practical application in design and construction in Ukraine.
By shifting most of the site work to factories, manufacturing becomes a critical phase in modular construction. Human-robot collaboration (HRC) is a promising approach to enhancing modular construction manufacturing (MCM) productivity while maintaining necessary flexibility. However, little attention has been paid to understanding, in a holistic manner, the past, present, and future of HRC in MCM. To fill in this gap, this study presents a review of 78 relevant publications on HRC in MCM, focusing on tasks, human roles, and interaction levels. HRC solutions are found applicable to various MCM tasks whereas existing research primarily focuses on timber component production. It also reveals that humans can play diverse collaborative roles and interact with robots at varying levels. Potential opportunities, challenges, and future directions are further discussed. The review deepens the understanding of HRC in MCM and inspires future research.
Bridging the gap between the material and geometrical aspects of a structure is critical in lightweight construction. Throughout the history of structural development, shape rationalization has been of prime focus for designers and architects, with biological forms being a major source of inspiration. In this work, an attempt is made to integrate different phases of design, construction, and fabrication under a single framework of parametric modeling with the help of visual programming. The idea is to offer a novel free-form shape rationalization process that can be realized with unidirectional materials. Taking inspiration from the growth of a plant, we established a relationship between form and force, which can be translated into different shapes using mathematical operators. Different prototypes of generated shapes were constructed using a combination of existing manufacturing processes to test the validity of the concept in both isotropic and anisotropic material domains. Moreover, for each material/manufacturing combination, generated geometrical shapes were compared with other equivalent and more conventional geometrical constructions, with compressive load-test results being the qualitative measure for each use case. Eventually, a 6-axis robot emulator was integrated with the setup, and corresponding adjustments were made such that a true free-form geometry could be visualized in a 3D space, thus closing the loop of digital fabrication.
The recent decades have witnessed the development of a new generation of space structures called free-form space structures. In this new family of space structures, due to the geometric nature of the structure, the orientation of the members varies substantially within the joints, meaning that the members need to be connected to the joints at different angles. The wide distribution of these angles throughout the structure will significantly affect the cost of fabrication. Therefore, accurate and automatic calculation of connection angles and their optimizations have always been of interest to researchers and manufacturers. This article has the following two main objectives. The first objective is to provide geometric calculations and obtain the connection angles of single-layer lattice space structures. The second, and more important objective is to review the existing methods and to develop a geometrical method for their optimization, referred to as the “node orientation optimization” method throughout this article. Using the mentioned method, a series of optimizations are carried out in a number of free-form lattice space structures and the results are studied.
Rapid urbanization negatively affects the built and biotic environment, necessitating interdisciplinary mitigation strategies. Current nature-based solutions that are integrated into building envelope design have proved to be beneficial. These solutions, however, are primarily anthropocentric and often overlook the potential to support other living organisms, such as animals and microbiota. Thus, a multi-species approach is envisioned to facilitate more holistic envelope-design solutions. While integrating ecological knowledge into architectural design often introduces decision-making complexity, multi-criteria decision-making can support multi-species building envelope design. This paper reviews such decision-making applications in two domains: building envelope design and ecological planning design. Using a systematic literature review methodology to compile relevant publications for full-text analysis, the results show significant disparities between the two domains. This is primarily driven by decision-making applications, the scale of analysis, criteria typology and external decision-maker engagement. However, we identified opportunities to sequentially employ multi-objective optimization and multi-attribute decision-making to mitigate the technical differences and facilitate interdisciplinary collaboration. Finally, we discuss future developments using hybrid multi-criteria decision-making to facilitate better architectural and ecological computer-aided design.
According to the construction leadership council: “smart construction is building design, construction, and operation that through collaborative partnerships makes full use of digital technologies and industrialized manufacturing techniques to improve productivity, minimize whole life cost, improve sustainability and maximize user benefits” [1]. So, referring to this definition, improving sustainability is one of its aims; thus, a significant relation between smart and sustainable construction is identified.Many researchers discussed the integration between smart and sustainable construction to achieve different objectives like selecting the best alternative green material, alternative model for a building, and suitable energy-saving method. As existing research utilized this synergy to gain improvements in the economic and environmental pillars of sustainable construction only, while many issues are there in the social pillar require improvements such as improving occupational safety and health during the construction phase, job security and welfare, improving the working environment and job satisfaction.Hence, this paper starts with an extensive literature review, that covers the status of the integration between smart and sustainable construction, and the existing application of this integration in sustainable construction’s three main pillars. Then the research focuses on highlighting the issues under the social pillar of sustainable construction that could be improved as a result of utilizing smart construction tools. This paper is supposed to fill the current gap in the literature, as it highlights the open issues and directions for future work associated with the integration between smart and sustainable construction.KeywordsSmart constructionSustainable constructionConstruction automationSustainable projectsSmart-sustainable practicesConstruction projectsSmart construction toolsBIM
Aggregate gradation and elongated and flat aggregate contents strongly affect the performance of asphalt mixtures. During the visual detection of these two indexes, the morphology in a single view is typically used for mass calculation. However, it has a significant error and affects the detection accuracy. Therefore, in this study, the morphologies of an aggregate from multiple views were collected during falling. Size features were also extracted for mass calculations. Two mass calculation methods, the multi-view equivalent volume models (MEVMs) and ensemble regression learning model (ERLM), were proposed in this study. MEVMs were constructed using multi-view shape features. The relationships between pixel volumes of MEVMs and actual aggregate mass were established through the least square method for mass calculations. Correlation analyses of multi-view size features were conducted and weakly correlated features were eliminated. The ERLM was combined with the K-nearest neighbor algorithm, multi-layer perceptron neural network, support vector regression algorithm, and ensemble decision tree using an adaptive weight assignment algorithm. The ERLM was trained with processed multi-view features for mass calculations. Finally, the feasibility of MEVMs and ERLM were verified through mass calculations of aggregates with different particle sizes and shapes. Both methods showed significantly improved correlation and accuracy, with the ERLM showing stronger generalization ability in particle size and shape scales than that of MEVMs. Therefore, the ERLM could be effectively applied for the visual detection of aggregate gradation and elongated and flat aggregate contents. The application of the proposed methods was verified in practical road engineering.KeywordsRoad engineeringAggregate massVisual detectionEnsemble learningMulti-view morphological information
O uso de modelos computacionais paramétricos possibilitou uma revolução na forma das edificações. No entanto, a liberdade formal trazida por esses modelos apresenta novos desafios, principalmente em relação ao processo construtivo e ao uso dos materiais nas arquiteturas com formas complexas. Logo, entender a construtibilidade, ou como os processos de fabricação e montagem e os materiais influenciam na geração da forma, é essencial para o desenvolvimento de uma arquitetura eficiente e eficaz. Com base nisso, este artigo tem como objetivo identificar e analisar o estado da arte relativo aos processos de fabricação e montagem de formas arquitetônicas complexas por meio de uma revisão sistemática da literatura (RSL). Após a pesquisa em cinco bases de dados, encontrou-se 142 trabalhos, dois quais 61 foram selecionados para análise. Esses trabalhos possibilitaram uma visão ampla da aplicação de materiais e técnicas de fabricação digital para construção de formas complexas, além de diferentes critérios de construtibilidade utilizados para análises das formas, citados em 17 trabalhos. Conclui-se que o desenvolvimento de formas arquitetônicas complexas demanda a integração entre o projeto da forma, os materiais de construção que serão utilizados e os processos de fabricação e montagem. Palavras-chave: Formas complexas. Construitibilidade. Modelos paramétricos algorítmicos. Abstract The use of parametric computational models led to a revolution in building shapes. However, the formal freedom brought about by parametric models has also posed new challenges, especially concerning the construction process and the use of materials in architecture using complex shapes. Therefore, for the development of an efficient and effective architecture, it is essential to understand constructability or how manufacturing and assembly processes and materials influence the generation of shapes. Hence, this article aims to identify and analyse the state of the art regarding the manufacturing and assembly processes of complex architectural forms through a Systematic Literature Review (SLR). After searching five databases, 142 papers were found, of which 61 were selected for analysis. These works offered a broad view of the application of materials and digital manufacturing techniques in the construction of complex shapes, as well as different constructability criteria used for shape analysis, mentioned in 17 papers. This study's conclusion is that the development of complex architectural forms requires the integration between the shape design, the construction materials that will be used, and the manufacturing and assembly processes.
Eine präzise, adaptive und individuelle Fertigung ermöglicht einen hohen Grad an Bauteildifferenzierung, die somit hocheffiziente und lastadaptierte Strukturen für den Betonfertigteilbau zugänglich macht. Während Fortschritte von Fertigungsseite durch zahlreiche Projekte in Forschung und Industrie demonstriert werden, so sind zugehörige Planungswerkzeuge weniger entwickelt. Um das volle Potenzial digitaler Fertigungsprozesse nutzen zu können, sind daher computerbasierte Methoden erforderlich, welche die flexible Anpassung von Bauteilgeometrien erlauben und eine fertigungsgerechte Planung ermöglichen. Die Modularisierung von Betonstrukturen muss den Anforderungen sowohl von Seiten der Tragfähigkeit wie auch der Fertigung gerecht werden. Planungswerkzeuge müssen diese Komplexität abbilden können. Simulationsbasierte Methoden, welche modularisierte Baustrukturen als komplexes System bauteilspezifischer Wechselwirkungen abbilden, bieten die Möglichkeit, bereits früh die Konsequenzen von Entwurfs‐ und Planungsentscheidungen abschätzen zu können. Dieser Beitrag zeigt einen agentenbasierten Planungsansatz auf, welcher insbesondere die additive Fertigung von Schalungen als Ergänzung bestehender Produktionskonzepte berücksichtigt. Die geometrischen Grundlagen für die simulationsbasierte Zerlegung von Bauteilen werden dargestellt und in einen durchgehenden Planungsprozess integriert.
View Video Presentation: https://doi.org/10.2514/6.2022-1138.vid In recent years, topology optimization (TO) has become more common for several types of structural design problems. Rapid prototyping and testing is often employed to validate designs that emerge from TO, but depending on designs’ complexity, structural behavior of physical prototypes can deviate from their computational counterparts. Such differences are caused, in part, by limitations on manufacturing processes, such as the need to fabricate large models from several smaller components. Although additive manufacturing (AM) can be more effective for fabrication of complex topologies, its limitations are generally less understood than those for traditional subtractive manufacturing. Understanding and incorporating limitations on AM into TO would allow the algorithm to produce not only optimal designs, but also those that are feasible for AM. In this paper, the effects of partitioning 3D printed models as smaller components that are glued together are investigated both experimentally and through finite element analyses. The experimental study indicates that differences in effective stiffness of a model and distribution of maximum principal strain will occur when partitioning a physical model derived from a multi-material Lindenmayer system (L-system) graph-based topology. Partitioning perpendicular through structural members is recommended since it proved to be the most consistent method employed in the studies in terms of affecting structural behavior of the geometry.
The morphogenetic design process of networking patterns produces anisotropic structural systems that can offer generative solutions for custom design applications. As an example of this type of pattern application, the leaf venation algorithm is introduced that can be customized through parametric inputs and density maps. This method is extended onto mesh surfaces incorporating multiple software applications combining aspects of parametric design, optimization and digital fabrication. The dynamic workflow is presented using a case study project titled “Calyx,” a public artwork completed using the computational tools developed as part of the research. The networking structural pattern of the sculpture yielded to the development of a geometry optimization process that allowed the digital fabrication of planarized structural members. The technical aspects of the design development and post-rationalization process for the construction of leaf venations patterns are discussed.
Computational design tools based on Autodesk’s DesignScript language have been used with geometry and topology modelling techniques in the design of a climatised free-form building envelope. This project involves structural and performance analysis tools applied to structural engineering, façade engineering and fabrication planning. The project has progressed from concept through tender phases. The particular geometry presented unique conditions that required non-standard solutions to be used; to this end
DesignScript was introduced to allow the design and engineering team to build a number of scripted topological façade models that explored alternative façade configurations. This paper combines a discussion about the specific fabrication project with a more generalised discussion of the role of computational tools in design and fabrication. The main interest is to explore the two-way relationship between practice and tool building by considering how computation can contribute to a practical fabrication project and equally important, how computational tools can be tested and refined by being used in practice on demanding projects.
This paper describes the development of an unreinforced, freeform vault consisting of 399 discrete limestone blocks with thicknesses ranging from 5 to 12 cm. The vault covers an area of 75 m2 and spans more than 15 m in pure compression, without mortar between the blocks. We discuss how the design of the vault and its individual pieces was entirely driven by constraints related to the fabrication process and to the architectural and structural requirements and timeline of the project. Furthermore, we describe the form-finding process of the shell’s funicular geometry, the discretisation of the thrust surface, the computational modelling and optimisation of the block geometry, and the machining process. Finally, we discuss some of the strategies that were developed for dealing with tolerances during fabrication and construction.
Architectural designs are frequently represented digitally as plane-faced meshes, yet these can be challenging to translate into built structures. Offsetting operations may be used to give thickness to meshes, and are produced by offsetting the faces, edges or vertices of the mesh in an appropriately defined normal direction. In a previous paper, we described a face-offsetting algorithm for resolving the revised combinatorics of the offset mesh produced by face-offsetting (Ross & Hambleton, 2015). That is, given an input mesh with no design constraints, the algorithm computes the exact offset by determining the new geometric and combinatorial structure of the offset mesh. One of the design freedoms available in that method is the opportunity to specify different offset distances on a per-face basis. In the present paper we consider the implications of this freedom.
One question of particular interest is: under what conditions does an offset mesh produced by variable rate face-offsetting also have a uniform distance edge-offset? To physically realise a mesh as a built structure usually requires that the mesh edges are used as the basis for structural members, with some structural depth. Therefore, given a mesh M it is particularly desirable to find an offset mesh M' in which the edges of M' are at a uniform perpendicular distance d from their corresponding edge in M. We present a description of meshes that admit uniform distance edge offsets as a consequence of a variable rate exact face offset, based on a graph-theoretic analysis of the underlying dual mesh. The potential advantage of this approach is that it can provide an opportunity to rationalise the physical realisation of the mesh as a constructible structure where all edge based members have the same depth.
The objective of this paper is to introduce an intuitive method for the modelling of free-form architecture with planar facets. The method, called Marionette by the authors, takes inspiration from descriptive geometry and allows to design complex shapes with one projection and the control of elevation curves. The proposed framework only deals with linear equations and therefore achieves exact planarity, for quadrilateral, Kagome and dual Kagome meshes in real-time. Remarks on how this framework relates to continuous shape parameterisation and on possible applications to engineering problems are made.
This paper presents the production and development of an adaptive robotically fabricated fiber composite compression shell with pneumatic formwork as a case study for investigating a generative behavioral design model and an adaptive, online mode of production. The project builds off of previous research at the University of Stuttgart on lightweight fiber composite structures which attempts to reduce the necessary formwork for fabrication while simultaneously incorporating structural, material and fabrication logics into an integrative computational design tool. This paper discusses the design development and fabrication workflow of the project, as well a set of strategies which were developed for online robotic programming in response to live sensor data.
This paper describes the work of Ramboll Computational Design during the design and construction of the Ongreening Pavilion timber gridshell. The structural approach involved form-finding bending-active timber laths, connected at intersections to form a doubly curved shell. The resulting form was simple to fabricate and assemble, realised using 6.5 mm thick Finnish birch plywood laths that could achieve high curvature while maintaining desired strength. Due to the random nature of the final lath topology, the resulting structure was extremely stiff in spite of its low material weight, acting similarly to a continuous monocoque. The fully demountable shell was first erected at Ecobuild 2014 in London.
Process-based biomimetics focuses on the transfer of biological principles to architectural construction. To realise the ICD/ITKE Research Pavilion 2014 -15, presented here by Moritz Doerstelmann, Jan Knippers, Valentin Koslowski, Achim Menges, Marshall Prado, Gundula Schieber and Lauren Vasey of the Institute for Computational Design (ICD) and Institute of Building Structures and Structural Design (ITKE) research team at the University of Stuttgart, sensor-driven robotic fabrication was combined with advanced design computation and simulation. This enabled the construction of an architectural fibre structure on a pneumatic mould, drawing on the complex design of the web of a water spider.
The design of free-form structures is governed by structural and geometric considerations, the latter ones being closely linked to the costs of fabrication. If some construction constraints have been studied extensively, the question of the repeatability of nodes in free-form structures has rarely been addressed yet. In this paper, a family of surfaces that can be optimized regarding typical geometrical constraints and that exhibit high node congruence is proposed. They correspond to particular meshes of moulding surfaces and are called isogonal moulding surfaces by the authors. The geometrical properties of these surfaces are discussed. In particular, it is shown how to derive edge offset mesh from them. It is also demonstrated that they represent all the possible meshes parallel to surfaces of revolution. Finally, the reader is introduced to some computational strategies linked to isogonal moulding surfaces.
This paper describes embedded rationality as a method for implicitly combining fabrication constraints into an interactive framework for conceptual design. While the concept of ‘embedded rationality’ has been previously discussed in the context of a parametric design environment, we employ this concept to present a novel framework for dynamic simulation as a method for interactive form-finding. By identifying categories of computational characteristics, we present a unified physics-solver that generalizes existing simulations through a constraint-based approach. Through several examples we explore conceptual approaches to a fixed form where the resulting effects of interacting forces are produced in real-time. Finally, we provide an example of embedded rationality by examining a constraint-based model of fabrication rationale for a Planar Offset Quad (POQ) panelization system.
The adoption of digital planning methods has given rise to an unprecedented formal freedom in architectural design. Free-form shapes enjoy considerable popularity in architectural production today. However, these shapes prove to be notoriously hard to fabricate. In the course of a funded research project we investigated the approximation of continuous double-curved surfaces by discrete meshes consisting solely of planar facets, which can be fabricated efficiently using standardised, mass-produced building materials.We introduce our geometrical approach, which is based on the intersection of tangent planes to the surface, and present the digital tools we conceived to integrate the processes of design rationalisation and form-finding.
This paper reviews the history and practices of geometry rationalization in non-standard architecture. Referring to numerous examples, the changing role of the architect between the Gothic era and today is discussed along with the architect’s interaction with the allied professions, in particular that of the structural engineer. It is shown that advanced geometry rationalization has been part and parcel of non-standard architecture for over a century. Following a decade in which this practice intensified markedly due to advances in digital modeling technology, the paper takes stock of this design challenge between sensational effect, industry transformation and a
re-emergence of the master builder paradigm. It discusses different geometry rationalization practices by distinguishing pre-, co- and post-rationalization, their bearing on the two architectural agendas of immersion into detailed technological design development on the one hand and of its delegation to supporting collaborators
on the other hand, and the consequent possibilities of disciplinary integration and disassociation.
The HygroSkin project explores a novel mode of climate responsive architecture based on the combination and interrelationships of material inherent behaviour, computational morphogenesis and robotic manufacturing. The dimensional instability of wood in relation to moisture content is employed to develop a meteorosensitive architectural skin that opens and closes in response to climate changes with no need for any technical equipment or a supply of external energy. Embedded within robotically fabricated, lightweight structural components made of elastically bent plywood panels, the responsive wood-composite apertures adjust the envelope’s porosity in direct feedback to changes in ambient relative humidity. The HygroSkin Pavilion was commissioned by the Fonds Régional d’Art Contemporain du Centre and now forms part of the permanent collection of the FRAC Centre in Orleans.
The paper presents a bottom-up design process based on the transfer of biomimetic design principles and digital fabrication strategies for modular fibre-based structures, as demonstrated on a full-scale prototype pavilion. Following the analysis of the structural principles of the beetle elytra, the material differentiation and the morphologic principles of the biological role model are transferred into design and fabrication strategies. Simultaneously, developments of a coreless robotic winding method for glass and carbon fibre reinforced composite elements are incorporated into the design process. The computational set-up developed for the entire workflow is presented, showing the integration of structural analysis with digital simulation, which enables the automatic generation of the robotic winding syntax for individually differentiated components. The investigations, simulation, fabrication and assembly process, which led to the realisation of a highly efficient lightweight architectural prototype, are explained in the current paper.
The research presented in this paper pursues the development and construction of a robotically fabricated, lightweight timber plate system through a biologically informed, integrative computational design method. In the first part of the paper, the authors give an overview of their approach starting with the description of the biological role model and its technical abstraction, moving on to discuss the computational modelling approach that integrates relevant aspects of biomimetics, robotic fabrication and structural design. As part of the validation of the research, a full-scale, fully enclosed, insulated and waterproof building prototype has been developed and realized: The first building featuring a robotically fabricated primary structure made of beech plywood. Subsequently, the methods and results of a geodetic evaluation of the fabrication process are presented. Finally, as the close collaboration between architects, structural and geodetic engineers, and timber fabricators is integral to the process, the architectural and structural potentials of such integrative design processes are discussed.
Introduction Design and Design Alternatives Drawings General Principles for Design for Manufacturability Processes and Materials for Producing the Design Design for Basic Processes-Metal Design for Secondary Operation Design for Basic Processes-Plastics Design for Assembly Computer Software Tools: Object-Oriented Programming and Knowledge-Based Systems Organizational Issues References Additional Reading
This paper describes a method for the production of thin-wall funicular (compression-only) structures from unique double-curved concrete components via a novel slump casting technique. The technique deploys fabric formwork within simple two-dimensionally cut frames to enable the efficient production of the unique parts necessary to tessellate form-found funicular geometries. Through the realisation of a high-tech / low-tech ecology of production, the paper seeks the reestablishment of generative pathways between each domain in the design-to-production cycle: architecture, engineering and fabrication. The method and resulting case study pavilions are situated within the historical trajectory of architectural form finding, specifically, the realisation of masonry vault structures.
Our article concerns the process of conception where one seeks to bring together an architectural form and the industrial techniques which enable its realization. It is an iterative process of, on the one hand, rationalizing geometry, and, on the other, sorting and combining production methods that both match the economics of the project and account for the constraints of technology. This back and forth essentially results in an optimization by which an industrial process best approaches the desired form.
The subject is illustrated by the example of the glazed canopies of “la Fondation Louis Vuitton pour la creation” in Paris, a project by Gehry Partners, which is currently in construction.
Motivated by increasing application in contemporary architectural projects, we showcase a unique state-of-the-art industrial process, which encompasses design and fabrication of free-form metal cladding for large doubly curved roofs and facades. The technology combines well-established methods of metal roofing with a completely digital workflow - starting from a 3D scan of the building, following with the approximation of the design surface as set of developable stripes and ending with the automated CNC-fabrication of individually curved panels from aluminium or steel coils. Since projects often require panel shapes and lengths, which are difficult to transport, the production units are mobile and can be shipped in two standard intermodal containers, enabling fabrication directly on-site. Geometrically, the system is based on tightly packed developable strips with non-parallel edges. Technically, it leads to a homogeneous, watertight and continuous surface without penetrations, which is easy to mount on a multitude of structural systems and thereby resolves the common problems that occur, when cladding doubly curved surfaces. The entire process has been successfully tested and proven on a number of large-scale projects, of which some are illustrated.
The Nuit Blanche Pavilion was an investigation that combined material behavior with the technical possibilities of current digital design and fabrication methods. The goal of the project was to develop a new form of lightweight structure. The project was inspired by a relationship between structure, geometry, material and appearance that can be found in biology. The project took advantage of a dynamic structural quality found in high-density polymers that was used to develop a self-supporting structural envelope.
This paper presents the detail design and fabrication process of the complex double curved structural steelwork for the 3 main Towers and the 2 compression towers of the Emirates Air-Line. The main towers consist of 2 spiraling and interlocking “helices” and 4 twisting” ribbon” plates. Rather than a more conventional approach of rationalizing the double curved steelwork into single curved segments, we employed a 3d steel forming technique typically used for shipbuilding which enabled us to archive the original reference design. To facilitate fabrication and pre-fabrication our highly detailed and parametric 3D model was used directly to develop the steelwork fabrication information and to cut and form the structural steel members themselves.
Poised between design research and full-scale realisation, prototypes in architecture provide a significant stepping stone for innovation. Through his New York-based studio THEVERYMANY, Mark Fornes explores the possibilities of coding and computer prototcols for design and fabrication through art installations and architectural structures. As prototypical projects, they are each defined by a single architectural concern, like a structure, enclosure or porosity; the intention being to realise the structure as a pleasurable spatial experience with potential for scalability.
Designers are becoming more directly involved in the fabrication process from the earliest stages of design. This book showcases the design and research work by some of the leading designers, makers and thinkers today.
Based on the recent work of Yang et al. [2011], we propose several intuitive tools to quickly create new architectural freeform shapes starting from a single input design, while conforming to a set of prescribed constraints and optimizing for specified quality measures. We allow the user to control the final shape by prescribing desirable curves on the final shape, access the desirable regions of the constrained mesh manifold using smartly selected 2D mappings, and computationally generate multiple design alternatives that satisfy the user hints. These tools allow the designer to intuitively navigate the constrained mesh manifold and pick desirable shapes using a design gallery interface. We demonstrate the efficiency of the proposed tools using various case studies.
This paper presents a design-to-fabrication process for folded sandwich structures that comprises surface to pattern conversion, manufacture rationalisation, and integral connection superposition. Folded sandwich structures are shown to possess a tessellated, origami-like structural form in which building component parameters are inherently dependant upon building surface parameters. Structural forms can therefore be designed with a minimum number of unique parts and with simultaneous consideration of surface and component constraints. The design-to-fabrication process is demonstrated for the Plate House, a cardboard shelter designed to meet transitional shelter packaged and deployed volume requirements. Additional prototypes are presented to demonstrate an extended set of parametric edge connection details for the production of cardboard, plywood, or steel folded sandwich structures. Prototypes are also presented to demonstrate how the method can be applied generally for the digital fabrication of developable 3D surfaces with a known crease pattern.
Rationalisation of architectural design is paramount to manufacturing and its construction. This paper presents a methodology of rationalisation of building envelope geometry. We discuss methods for understanding and addressing design complexity; review two theoretical models of rationalisation: the pre-rational and post-rational design principles; illustrate their benefits and limitations and demonstrate their meeting point proposing an integrated performance-oriented model for analysis and design of building envelopes, using digital design techniques.
This paper tracks the design, fabrication and installation of a complex wood ceiling in the Burj Khalifa office lobby in Dubai, UAE. Self-detailing and selfdocumenting systems are here understood as the use of parametric tools to capture and reuse design and fabrication know-how. This approach seeks not to supplant the designer or fabricator’s skills, but to create a shared platform for material innovation open to all the participants in the design team. By treating the production and detailing of this case study project as a system instead of a discreet design object, the authors also seek to illustrate the changing role of computational design tools and the implications for the practices of detail design and fabrication.
Case studies are given on the usage of the CATIA/Digital Project Knowledgeware environment to capture design intent and fabrication details in a system that allows them to adapt to new geometric configurations given different inputs; material bending limits and systems used to describe and map their physical constraints; automated tools built around the sorting and managing of wood veneers; and rationalization strategies related to wood bending and fabrication.
This paper presents a novel approach to non-standard timber assembly - Robotic Timber Construction (RTC) - where robotic fabrication is used to expand additive digital fabrication techniques towards industrial full scale dimensions. Featuring robotic systems that grasp, manipulate, and finally position building components according to a precise digital blueprint, RTC combines robotic assembly procedures and advanced digital design of non-standard timber structures. The resulting architectural morphologies allow for a convergence of aesthetic and functional concerns, enabling structural optimisation through the locally differentiated aggregation of material. Initiated by the group of Gramazio Kohler Research at ETH Zurich, this approach offers a new perspective on automated timber construction, where the focus is shifted from the processing of single parts towards the assembly of generic members in space. As such, RTC promotes unique advantages over conventional approaches to timber construction, such as, for example, CNC joinery and cutting: through the automated placement of material exactly where it is needed, RTC combines additive and largely waste-free construction with economic assembly procedures, it does not require additional external building reference, and it offers digital control across the entire building process, even when the design and assembly information are highly complex. This paper considers 1) research parameters for the individual components of RTC (such as computational design processes, construction methods and fabrication strategies), and 2) the architectural implications of integrating these components into a systemic, unifying process at the earliest stages of design. Overall, RTC leads to profound changes in the design, performance and expressive language of architecture and thus fosters the creation of architecture that profoundly reinvents its constructive repertoire.
Advanced design, simulation and fabrication technologies facilitate the exploration and transferring of the morphological principles of fibrous systems from biology to technology. The ICD/ITKE Research Pavilion 2012 pioneered such an approach for architecture. Jan Knippers, Riccardo La Magna, Achim Menges, Steffen Reichert, Tobias Schwinn and Frédéric Waimer of the Institute for Computational Design (ICD) and Institute of Building Structures and Structural Design (ITKE) research team at the University of Stuttgart describe how they approached the design of the pavilion, which is located on the school's campus.
Advances in computation challenge established design approaches in architecture through a much deeper integration of form generation and materialisation. Tobias Schwinn, Research Associate at the Institute for Computational Design (ICD), University of Stuttgart, and Guest-Editor Achim Menges, Director of the ICD, introduce how the potentials and constraints of robotic fabrication can now be explored as generative drivers in agent-based design. This enables architectural innovation in unison with fabricability, structural capacity and spatial performance, as demonstrated by the Landesgartenschau Exhibition Hall in Schwäbisch Gmu"nd, Germany, the world's first building with a robotically fabricated segmented timber shell as its primary structure.
