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The implementation of adaptive elements into an experimental high‐rise building
Abstract
Dedicated to our speaker, Prof. Werner Sobek, in honour of his 65th birthday
In 2017, the University of Stuttgart started a Collaborative Research Centre with the title Adaptive Skins and Structures for the Built Environment of Tomorrow. The goal of this research project is to find an answer to today's most urgent social and ecological questions as the global population continuously increases and the available resources remain limited. As the central approach to the solution of this problem, adaptive elements will be included in the structure, the interior and the façade of an experimental 37 m tall building. This paper introduces the topic of adaptivity in building structures and provides an overview of the research topics applied in this globally unique adaptive high‐rise building. Due to the complexity of research topics of this Collaborative Research Centre, this paper only covers the research concerning the experimental high‐rise building.
... Mentre la maggior parte dei progetti mira a un solo obiettivo di adattamento, il grattacielo dimostrativo dell'I-LEK (Institute for Lightweight Structures and Conceptual Design) ne combina diversi (Figg. 3-5): con attuatori integrati, la struttura di supporto reagisce in modo dinamico a tempeste e terremoti, compensando le vibrazioni e i casi di carico massimo (Weidner et alii, 2018). Sono in fase di sviluppo anche facciate adattive e ambienti che rispondono a mutevoli esigenze specifiche. ...
... While most projects only aim at one adaptation goal, the demonstrator high-rise by ILEK (Institute for Lightweight Structures and Conceptual Design) combines several . With integrated actuators, the supporting structure reacts dynamically to storms and earthquakes and compensates vibrations and maximum load cases (Weidner et alii, 2018). Adaptive façades and an individually adapted room climate are also being developed. ...
This paper describes the potential of adaptive architecture to mediate not only technically but also socially and aesthetically between humans and the environment. Compensating global change through architecture does not change human behaviour; the challenge is to involve and activate each inhabitant. By implementing the principle of adaptation in all dimensions, a step towards a healthy and resilient relationship between humans and earth can be taken. In this holistic approach, historical and contemporary projects in Architecture and Art are discussed and systemic, explorative, social and aesthetic perspectives are taken. As a mediator adaptive architecture makes a global system experienceable in the local, supports its inhabitants to improve their relationship to the Earth and adapt.
... Steel elements allow for a high reliability of sensor measurements; moreover, the wide range of available profile sections enables the integration of both parallel and serial actuation (Weidner et al., 2018). For these reasons, the primary structure of D1244 is made of steel, as this is the ideal material to carry out initial testing on large scale adaptive structural system. ...
... On the contrary, with serial actuation there is only resistance from the stiffness of the rest of the structure but none from the hosting element, and thus a larger part of the structure can be controlled through serial actuation . As large forces up to 400 kN are needed to actuate D1244 structure, hydraulic cylinders have been employed (Weidner et al., 2018). This limit value is defined as a result of the coordination of the requirements coming from structural and mechanical engineers. ...
An interdisciplinary research team of the University of Stuttgart has been working extensively since 2017 on the development and integration of adaptive systems and technologies in order to provide solutions for a more sustainable built environment. An experimental 36.5 m tall high-rise building, called D1244, was designed and completed in 2021 to show the potential of adaptive structures and facades as well as to verify on a real scale the developed systems and the related numerical predictions. The building was designed to offer a flexible experimental platform: each component is dismountable so that structural as well as facades elements can be replaced with new ones introducing new functionalities to be investigated. The structure is currently equipped with twenty-four hydraulic actuators that are installed in the columns and diagonal bracers. Strain gauge sensors and an optical tracking system are employed to monitor the state of the structural system. This paper describes the design and construction of the adaptive tower as well as the preliminary experimental testing on different scaled structural prototypes. The research work on these prototypes provided relevant information for the final set-up of the high-rise building. An outlook on future research, including the planned first structural testing phase and the implementation of adaptive façade systems, is included at the end.
... The "whole-life" or "total" energy function adopted in Senatore et al. (2019) is related to the global warming potential (GWP) of associated greenhouse gas emissions (GHG) as both embodied and operational energy can be expressed in equivalent carbon (kgCO 2 -eq). Recent experimental studies have been carried out on a large-scale high-rise adaptive tower of a height of 36.5 m and 5 m × 5 m of footprint Weidner et al. (2018). The frame structure is equipped with 24 actuators that are installed in series with some of the diagonal bracings and in parallel with some of the column elements. ...
... The experimental validation of the design methodology formulated in this work has been carried out on a medium-scale prototype structure. Results presented in this work are supported by other studies on prototype structures of similar scale as well as largerscale ones (Weidner et al., 2018) therefore showing potential for application in practice. Future work could consider further large-scale experimental tests using a material other than steel and structural types other than trusses and frames to generalize the conclusion reached in this work. ...
This paper presents an experimental validation of a new design method for adaptive structures that counteract the effect of loading through shape morphing. The structure is designed to morph into target shapes that are optimal to take external loads through combined optimization of structural layout and actuator placement. The prototype tested in this study is a simply supported spatial truss that spans 6.6 m with a span-to-depth ratio of 44/1. Shape adaptation is achieved through controlled length changes of 12 linear actuators that are strategically integrated into structural elements. A new mechanics-based framework has been formulated to enable real-time control. Linear-sequential shape optimization is employed to predict target shapes under loading. Actuator commands are computed through an iterative process that accounts for geometric nonlinearity. This formulation allows a reduction of computation time by four orders of magnitude compared with a nonlinear programming formulation. Experimental testing has shown that significant stress homogenization is achieved through shape adaptation, which results in up to 45% savings of material mass compared with a weight-optimized passive structure. Depending on the energy source employed for adaptation, the equivalent carbon is reduced by up to 29% and 43% in the case of non-renewable and 100% renewable energy mix, respectively.
... For this purpose, parts of the actuator system or the entire actuator system are integrated into the structure. A concept for the manipulation of beams subjected to bending by means of integrated fluidic actuators has been presented in Weidner et al. 19 For this purpose, actuators are employed to introduce a force eccentric to the neutral fiber into the beam. The resulting moment counteracts the bending moment caused by the external load and thus reduces the deflection of the beam. ...
... The actuators adapted for this application are also presented. 19 Thus, these dimensions correspond to a realistic scale, but the beam is still easily manageable for experimental testing. The weight of the adaptive beam is approximately 490 kg. ...
As the world population keeps growing, so does the demand for new construction. Considering material resources are limited, it will be unfeasible to meet such demand employing conventional construction methods. A new resource‐saving approach is provided by adaptive structures. By using sensors, actuators and control units, structures are enabled to adapt to loads, for example to compensate for deformations. Since deformations are dominant in the design of bending‐stressed load‐bearing structures, adaptivity enables such structures to be realized using less material and achieving the same load‐bearing capacity in comparison to conventional designs. This article presents a concrete beam of typical building dimensions that compensates deflections by means of integrated fluidic actuators. These actuators offer the possibility of reacting optimally to general loading. The investigation is carried out on an approximately 4 m long beam with integrated hydraulic actuators. To ensure the overall functionality, accurate dimensioning of the beam as well as the hydraulic system is mandatory. Analytical design of the beam and actuation system are carried out for pre‐dimensioning. Experimental testing validates the function and demonstrates that the adaptive beam works as predicted. This article is protected by copyright. All rights reserved.
... Aktuierungsprinzipien: a) serielle und b) parallele Aktuierung [7] Actuation principles: a) serial and b) parallel actuation [7] sieren. [12,13]. ...
... Aktuierungsprinzipien: a) serielle und b) parallele Aktuierung [7] Actuation principles: a) serial and b) parallel actuation [7] sieren. [12,13]. ...
Adaptive Gebäudehüllen und Tragwerke sind ein möglicher Weg hin zu mehr Ressourceneffizienz im Bauwesen. Eine aktive Manipulation der Geometrie und des Tragwerkverhaltens ermöglicht es, Spannungsverteilungen zu optimieren, Verformungen zu reduzieren und Schwingungen zu dämpfen. Adaptive Gebäudehüllen wiederum können sich an wechselnde Bedingungen im Innen‐ bzw. Außenbereich anpassen und besser auf Nutzerbedürfnisse eingehen als herkömmliche Systeme. Adaptivität bedeutet die Manipulierbarkeit der Gebäudehülle oder des Tragwerks – und erfordert daher Aktuierung, Sensorik, Steuerungstechnik und Regelungskonzepte. Das übergeordnete Ziel der Adaptivität ist eine Minimierung des Material‐ und Energieverbrauchs sowie eine Reduktion der mit dem Bauwerk verbundenen direkten und indirekten Emissionen von Treibhausgasen. Das Konzept der Adaptivität wird seit vielen Jahren an der Universität Stuttgart erforscht. Seit 2017 sind diese Arbeiten im interdisziplinären Sonderforschungsbereich SFB 1244 zusammengefasst. Zur Verifizierung der gesammelten Erkenntnisse wurde auf dem Universitätscampus in Stuttgart‐Vaihingen Anfang 2021 der Demonstrator D1244 errichtet – das weltweit erste adaptive Hochhaus. Das ca. 36,5 m hohe Gebäude dient als multifunktionale Experimentalplattform, in dessen Stahltragwerk 24 hydraulische Aktoren integriert sind. Jedes Bauteil kann einzeln entnommen und gegen neu entwickelte adaptive Systeme ausgetauscht werden. Der Demonstrator erlaubt in den kommenden Jahren eine flexible Erprobung und Validierung unterschiedlichster Technologien und Materialien im Bereich des Tragwerks und der Fassade.
... This can be compensated for by activating the bracings diagonally opposite. The actuator placement comes from two different load cases, considering static and dynamic loads as explained in [25] using 24 actuators in total. Several sensors ensure a sufficient controllability and observability. ...
... Adaptive load-bearing structure of the high-rise demonstrator for the CRC 1244[25]. ...
The consumption of construction materials and the pollution caused by their production can be reduced by the use of reliable adaptive load-bearing structures. Adaptive load-bearing structures are able to adapt to different load cases by specifically manipulating internal stresses using actuators installed in the structure. One main aspect of quality is reliability. A verification of reliability, and thus the safety of conventional structures, was a design issue. When it comes to adaptive load-bearing structures, the material savings reduce the stiffness of the structure, whereby integrated actuators with sensors and a control take over the stiffening. This article explains why the conventional design process is not sufficient for adaptive load-bearing structures and proposes a method for demonstrating improved reliability and environmental sustainability. For this purpose, an exemplary adaptive load-bearing structure is introduced. A linear elastic model, simulating tension in the elements of the adaptive load-bearing structure, supports the analysis. By means of a representative local load-spectrum, the operating life is estimated based on Woehler curves given by the Eurocode for the critical notches. Environmental sustainability is increased by including reliability and sustainability in design. For an exemplary high-rise adaptive load-bearing structure, this increase is more than 50%.
... Adaptive structures can control forces and deflections to stay within required limits such that the effect of external loading is reduced instead of relying only on passive loadbearing resistance. Several systems have been studied to control the structural response including building frames equipped with active bracings/columns (Reinhorn et al., 1993;Wagner et al., 2018;Weidner et al., 2018) and variable stiffness joints as well as bridges equipped with active cable-tendons (Rodellar et al., 2002;Xu et al., 2003). Through integrated structure-control optimization (Smith et al., 1991;Begg and Liu, 2000;Soong and Cimellaro, 2009;Frohlich et al., 2019) civil structures can be designed to adapt (e.g., react positively) to rare loading events of high intensity in order to operate closer to required limits, which results in a better material utilization compared to equivalent weight-optimized passive structures (Teuffel, 2004;Sobek, 2016;Böhm et al., 2019). ...
... In this work, actuators are assumed to be installed in series, and thus they have to carry the full force in the corresponding element. Another approach is to consider the actuators in parallel with the elements thereby decoupling the active elements from load transfer (Weidner et al., 2018;Böhm et al., 2020). This approach could be beneficial for control through nilpotent eigenstrain where the main objective is force control. ...
This work presents force and shape control strategies for adaptive structures subjected to quasi-static loading. The adaptive structures are designed using an integrated structure-control optimization method developed in previous work, which produces minimum “whole-life energy” configurations through element sizing and actuator placement optimization. The whole-life energy consists of an embodied part in the material and an operational part for structural adaptation during service. Depending on the layout, actuators are placed in series with the structural elements (internal) and/or at the supports (external). The effect of actuation is to modify the element forces and node positions through length changes of the internal actuators and/or displacements of the active supports. Through active control, the stress is homogenized and the displacements are kept within required limits so that the design is not governed by peak demands. Actuation has been modeled as a controlled non-elastic strain distribution, here referred to as eigenstrain. Any eigenstrain can be decomposed into two parts: an impotent eigenstrain only causes a change of geometry without altering element forces while a nilpotent eigenstrain modify element forces without causing displacements. Four control strategies are formulated: (C1) force and shape control to obtain prescribed changes of forces and node positions; (C2) shape control through impotent eigenstrain when only displacement compensation is required without affecting the forces; (C3) force control through nilpotent eigenstrain when displacement compensation is not required; and (C4) force and shape control through operational energy minimization. Closed-form solutions to decouple force and shape control through nilpotent and impotent eigenstrain are given. Simulations on a slender high-rise structure and an arch bridge are carried out to benchmark accuracy and energy requirements for each control strategy and for different actuator configurations that include active elements, active supports and a combination of both.
... The number of research topics incorporated in SFB 1244 is very large. Therefore, this paper mainly concentrates on the research fields applied to an experimental high-rise building's structure, which was first introduced in (Weidner et al., 2018) and is currently being realized on the campus of the University of Stuttgart. Fig. 4 shows a picture of the mock-up of the 36.5 m tall structure. ...
... However, in this case the active element also has to withstand the forces induced into the system by external loadings since it is now part of the load path. This leads to higher safety requirements for the active elements (Weidner et al., 2018). The analysis of safety aspects for adaptive structures is considered in a separate research project as part of SFB 1244 (Ostertag et al., 2018). ...
Whilst most research focuses on the reduction of operative energy use in buildings, the aspect of which (and how many) materials are used is often neglected and poorly explored. However, considering the continuous growth of the global population and the limited availability of resources, it is clear that focusing on operative energy alone is too short-sighted. The tasks lying ahead for architects and engineers cannot be accomplished with conventional methods of construction. With a share of 50-60% of global resource consumption, the building industry has a decisive impact on our environment. If business as usual continues, resources will be significantly depleted in a matter of decades. Therefore, researchers of the University of Stuttgart are investigating the concept of adaptivity as a promising method for saving resources in the built environment. The term adaptivity in the context of building structures was first introduced by Werner Sobek. It describes a method where sensors, actuators and control units are implemented in systems or facades in order to oppose physical impacts in an ideal way. The applicability of this method will be verified on an experimental high-rise building at the University campus in Stuttgart. Thus, this paper describes this innovative research project and depicts the concept of adaptivity in high-rise structures. Furthermore, it gives an overview of potential actuation concepts and the interdisciplinary challenges behind them.
... In this paper, two different types of linear actuation are considered (Figure 1)-serial actuation (a) and parallel actuation (b). In the case of serial actuation, an actuator is integrated into the load path of the structure, whereas parallel actuation adds an actuator parallel to an existing passive element (Weidner et al., 2018). The actuator force resulting from actuator extension is defined as positive and the actuator force from retraction as negative. ...
... The method of influence matrices was developed during the interdisciplinary design process of a large-scale adaptive high-rise prototype, which is currently being realized on an experimental platform at the University of Stuttgart. Upon its completion, it will be the world's largest adaptive structure with a total height of 36 m, consisting of 12 identical floors, which are separated into four similar units (Weidner et al., 2018). Eight hydraulic cylinders are implemented as parallel actuators in the columns of unit 1 and 2 and a further 16 serially incorporated hydraulic actuators in the structure's diagonal bracing (eight in unit 1, and four in each unit 2 and 3) complete the actuator placement. ...
Due to the already high and still increasing resource consumption of the building industry, the imminent scarcity of certain building materials and the occurring climate change, new resource- and emission-efficient building technologies need to be developed. This need for new technologies is further amplified by the continuing growth of the human population. One possible solution proposed by researchers at the University of Stuttgart, and which is currently further examined in the context of the Collaborative Research Centre (SFB) 1244 Adaptive Skins and Structures for the Built Environment of Tomorrow is that of adaptivity. The integration of sensors, actuators, and a control unit enables structures to react specifically to external loads, when needed (e.g., in the case of high but rare loads). For example, adaptivity in load-bearing structures allows for a reduction of deflections or a homogenization of stresses. This in its turn allows for ultra-lightweight structures with significantly reduced material consumption and emissions. To reach ultra-lightweight structures, i.e., adaptive load-bearing structures, two key questions need to be answered. First, the question of optimal actuator placement and, second, which type of typology (truss, frame, etc.) is most effective. One approach for finding the optimal configuration is that of the so-called influence matrices. Influence matrices, as introduced in this paper, are a type of sensitivity matrix, which describe how and to which extend various properties of a given load-bearing structure can be influenced by different types of actuation principles. The method of influence matrices is exemplified by a series of studies on different configurations of a truss structure.
... The design of the actuators needed to fulfill various requirements, which were already presented in Weidner et al., 2018. On the one hand, the active supports must apply both tensile and compressive forces in order to be able to influence the loads and on the other hand, the diagonal bracing elements must only conduct tensile forces due to their flexible design. ...
... Due to the predominant load cases, the principle of parallel actuation was implemented in the support columns and the principle of serial actuation in the diagonal bracing elements. The advantages and disadvantages were briefly outlined in 2.2 and explained in more detail in Weidner et al., 2018. In order to avoid bending stresses as far as possible, the actuator systems were integrated centrically into the load path of the support columns and the diagonal bracing elements. ...
... In the Collaborative Research Centre (SFB) which was established at the University of Stuttgart in 2017, concepts for adaptive skins and structures with their respective potentials and challenges are investigated. An essential part of the research project is the construction and realization of a 36 m high experimental high-rise building, which will be located on the campus of the University of Stuttgart [10]. This building serves as demonstrator to prove the functionality of all adaptive components, the effectiveness of the concept of adaptivity, and the developed planning methodology. ...
... Therefore, the basis is the availability of detailed component data with the same functional performance. Various actuation concepts with different requirements on the mass demand such as parallel or serial actuation [10] can also be used in this context. The evaluation on the basis of performance specifications provides the last possible stage of assessment in order to integrate changes into current planning and can be understood as the last target control before the building will be realized. ...
Eine Antwort auf den großen und fortschreitenden Ressourcenverbrauch im Bauwesen können leichte und zugleich adaptive Lösungsansätze für Gebäudehüllen und ‐strukturen darstellen. Dazu müssen sie sowohl für schadensfreie Bauwerke mit passender Aufenthaltsqualität als auch für eine deutlich höhere Ressourceneffizienz sorgen. Beides gilt für den gesamten Lebensweg und trotz der für die Adaptivität benötigen zusätzlichen Betriebsenergie. Im Rahmen einer vorangegangenen Untersuchung adaptiver Leichtbaukonstruktionen [1] für Fassaden wurde die bauphysikalische Funktionalität und Umweltwirkung einiger Beispiele auf Bauteilebene behandelt. Im hier vorliegenden Beitrag wird nun der Betrachtungshorizont auf die Raumebene erweitert, um z. B. neben Kennwerten für Wärme‐ und Feuchteschutz der Hülle auch die Behaglichkeit im Raum als Bewertungsmaßstab heranzuziehen. Natürlich erhöhen sich damit der Aufwand und die Komplexität der Bilanz, dafür lässt sich aber fundierter das Anwendungspotenzial adaptiver Alternativen einschätzen und über deren Weiterverfolgung entscheiden. Dazu werden drei herkömmliche, teils massive und teils leichte Konstruktionen, sowie vergleichbare adaptive Fassaden auf Raumebene untersucht und bewertet. Als wesentliche Bewertungskriterien gelten dabei quantitative Aussagen zur Erfüllung bauphysikalischer Anforderungen und zu ökologischen Umweltwirkungen. Im Ergebnis der methodenübergreifenden Forschung zeigt sich, dass adaptive Konstruktionen fallspezifisch, z. B. standortbezogen, beachtliches Potenzial zur Ressourcenreduktion ohne Funktionseinschränkungen mit sich bringen.
... Lattices, tesselations, and grids as repetitive objects are helpful as preliminary design structures [5, 6, 18, 30-32, 34-36, 40, 46-49, 51]. The rigidity analysis naturally gives valuable input for a three-dimensional frame structure in building design [8,13,28,41,59,61] and material science [20,58,62]. Some graph-theoretical characterization for bar-braced scaffolding was given in [21,33,39]. ...
We present a rigidity decision problem of constrained cubic grids in any given bracing pattern. The cubic grid bar and joint frameworks are not rigid. Additional constraints are required for rigidity. These constraints can be pinned down joints and additional bracing elements. Scaffoldings are not rigid cubic grid structures whose specific joints are pinned down. Inserting cable, strut, or rod bracing elements makes the framework rigid. Our model, which provides a linearly complex algorithm, has practical implications in testing the strong connectedness of a corresponding directed graph, contributing to the field of rigidity in structural engineering and motions of cable controlled pinned down cubic mechanisms.
... building D1244, adaptive columns and adaptive bracings were implemented by adapting classical hydraulic cylinders . The development of the actuators (cf. Figure 1) is described by Burghardt et al. (2021;2023), while the actuation concept for the D1244 and more high-rises is described by Weidner et al. (2018) and Steffen et al. (2022) With the hydraulic actuators implemented, the deflection, e.g., caused by wind load, of the high-rise can be manipulated up to a frequency of 8 Hz with actuator forces up to 400 kN. In a predecessor project, the use of hydraulic cylinders in a tripod construction at the supports homogenized stresses in a wooden shell structure and dampened vibrations (Neuhaeuser et al., 2013). ...
Adaptive structures have the potential to play a significant role in saving resources in the construction industry in the future. For realisation, this requires actuators that meet the requirements of different buildings with their specific load-bearing structures. In the past, the actuators were mainly developed particularly for one exemplary load-bearing structure. This paper analyses the primary classifications for buildings, followed by challenges of adaptive structures, before outlining the draft of a framework for actuators for adaptive structures to speed up and simplify development.
... Comparing the requirements with advantages and disadvantages in [32] and the considerations in [36], hydraulics appear to be an appropriate solution due to their high energy density, long lifetime, and mature technology. The highest energy density can be achieved with hydraulic direct drives. ...
A high proportion of the CO 2 emissions worldwide are caused by the construction sector or are associated with buildings. Every part of the industry needs to reduce its share of emissions, so the building sector must also do its part. One possible solution for achieving this reduction in the field of load-bearing structures is the use of adaptive structures. This research focuses on adaptive slab structures, which require specific actuators to be integrated into the system. Conventional actuators are not suitable due to the prevailing requirements, namely installation space and performance. For this investigation, the actuator is divided into different functional components. A rough description of the requirements for one component, namely the energy converter, is given. Different concepts are developed, tested, and compared with numerical results. Due to the requirements, the concepts are limited to hydraulics. The authors then present a comparison of different simulation strategies for the energy converter. Overall, this paper provides a new contribution to the design of energy converter concepts for integrated hydraulic actuators in slabs, along with experimental verification of the working principle of the energy converters to meet the requirements. A simplified numerical model is proposed to estimate the behavior of the energy converter during the early design phase.
This paper is an extended version of our published conference paper Bosch, M.J.; Nitzlader, M.; Bachmann, M.; Binz, H.; Blandini, L.; Kreimeyer, M. Experimental Testing of Actuator Chambers of Integrated Fluidic Actuators for Adaptive Slabs.
... Adaptive structures embody sensors and actuators to maintain an optimal structural state against changing load conditions through active control (Soong 1988). An extensive body of work exists on the actuation of discrete systems such as trusses and frames (Reinhorn et al. 1993;Senatore et al. 2011Senatore et al. , 2018Weidner et al. 2018;Reksowardojo et al. 2022). However, the actuation of continuous systems such as plates and shells has received little attention. ...
... The transition from adaptive structures being a theoretical research topic to building practice has already begun. In 2021 the construction of an adaptive high-rise tower in Stuttgart was finished as part of a research project, and this demonstrator is currently being tested [2]. For this transition, one of the most important aspects still to be covered by research is the topic of safety. ...
... Im Sonderforschungsbereichs (SFB) 1244 ,,Adaptive Hüllen und Strukturen für die gebaute Umwelt von morgen" untersucht ein interdisziplinäres Forschungsteam Tragwerke und Fassaden, die ihr Verhalten und ihre Eigenschaften selbstständig an die Erfordernisse der sich ständig ändernden Umgebung anpassen [7]. Im Zuge dessen erfolgte 2021 erstmalig die Errichtung eines adaptiven Tragwerks für ein reales Gebäude in Form eines Demonstrator-Hochhauses [8,9]. Zur Manipulation dieses Tragwerks werden gezielt Stützen und Aussteifungen aktuiert. ...
Adaptive Tragwerke stellen einen Ansatz dar, um den Materialbedarf und die Emissionen über alle Phasen des Lebenszyklus eines Gebäudetragwerks zu reduzieren. Dazu werden Sensor-Aktor-Systeme in die Tragstruktur integriert, die den Lastabtrag gezielt beeinflussen. Im Jahr 2021 wurde an der Universität Stuttgart ein 36,5 m hohes Demonstrator-Hochhaus mit adaptivem Tragwerk errichtet. Für die Lastmanipulation innerhalb des Tragwerks wurden hydraulische Aktoren in Stützen und Aussteifungselemente eingebaut. In diesem Beitrag wird die Entwicklung dieser aktuierbaren Tragwerkselemente vorgestellt.
... To meet environmental policy goals, it seems obvious, that the construction sector has to evolve. The concept of adaptive structures allows, among others, for ultra-lightweight construction and thereby offers a great potential to reduce the resource consumption in the construction sector ( [3]). ...
... Given the strength and actuation force of wood, such applications as responsive actuators should not have to be limited to either the small-scale parts or purely environmental actuation. Hygroscopic wood actuation can be tangibly imagined as integrated material actuators combined with digital control strategies, replacing hydraulic mechanical actuators currently used in large-scale adaptive structures [106]. Further, in responsive and/or fabrication systems, self-shaping is valuable as a distributable low-tech method of generating highly effective geometries in many parts of the world where technical building knowledge is limited, in extremely remote environments on Earth, underwater or in Space. ...
Form and structure play critical roles in architecture yet the processes required to produce performative geometries often require tremendous resources and physical effort. Advances in computational design and the programming of digital fabrication machines have increased variety, precision and automation in the production of building components. However, the underlying processes of generating material form still rely predominantly on brute-force methods of shaping. This research presents an alternative, material programming approach to the fabrication of building components in which shape is generated by activating the material’s inherent capacity to change in relation to external stimuli. The concept is investigated through the development of an innovative method of self-shaping manufacturing for load-bearing curved wood building components. The dissertation introduces material programming in the context of architectural design, fabrication processes, wood materials and existing self-shaping and development of a computational design-to-fabrication approach. In parallel the challenges of upscaling and predictability are addressed through computational mechanics and physical prototyping. The concept is then adapted and implemented through the design and production of components for a building demonstrator, the of the material system. The material programming approach is therefore shown as a simple yet sophisticated method of fabrication for a novel, ecological and effective architecture.
... When a change in the structural and/or environmental characteristics occurs, it might result in significant degradation of control performance which therefore poses a reliability issue. Active control devices, such as active tuned mass dampers [16] and bracing systems [17], provide control forces through actuation based on feedback from sensors that measure the structure response. Although these active devices perform significantly better than passive ones and are effective in a wide range of conditions, they typically require a high-power density supply and a complex control system [12]. ...
This paper presents experimental testing of a new semi-active vibration control device comprising a shape memory polymer (SMP) core that is reinforced by an SMP-aramid composite skin. This control device works as a load-transfer component that can be integrated into truss and frame structures in the form of a joint. At the material level, thermal actuation from ambient (25 °C) to transition temperature (65 °C) causes a significant 40-fold increase in damping due to viscoelastic effects. At the component level, uniaxial tensile and four-point bending tests have shown that tensile strength depends primarily on the bond strength between the reinforcement skin and the structural element while flexural strength depends on the strength of the reinforcement skin fibers. Through cyclic testing, it has been observed that material viscoelasticity is beneficial to ductility and energy dissipation. When the joint core is actuated to the SMP transition temperature, axial and flexural stiffness decrease by up to 50% and 90%, respectively. The property change at material and component levels enable tuning frequency and damping ratio at the structure level, which has been successfully employed to mitigate the dynamic response of a 1/10 scale 3-story prototype frame under resonance and earthquake loadings.
... Figure 2 shows the schematic application of the adaptive concrete columns under an external compressive (blue) or tensile (red) axial force and the resulting stresses. The field of adaptive civil engineering structures distinguishes between two main categories of linear actuation concepts due to the differences in mechanical behavior and adaptation potentials [33]: actuation in series and parallel actuation [34]. One major difference, which is also relevant for the design of actuators, is the difference in the loading of the actuator. ...
The building industry accounts for half of the global resource consumption and roughly one third of global CO2 emissions. Global population growth and increasing resource scarcities require engineers and architects to build for more people with less material and emissions. One promising solution are adaptive load-bearing structures. Here, the load-bearing structure is equipped with actuators, sensors, and a control unit which allows the structure to adapt to different load cases, resulting in substantial material savings. While the first prototypes use industry standard actuators to manipulate deformations and stress states, it is essential to develop actuator concepts which fit the specific requirements of civil engineering structures. This paper introduces new concepts for linear actuators, developed within the Collaborative Research Centre (SFB) 1244 Adaptive Skins and Structures for the Built Environment of Tomorrow, which can be used as adaptive concrete columns. The concept of an actuator which actuates a concrete column by external compression through hydraulic pressure is discussed in further detail. This concept allows for controlled axial extension while also increasing the compressive strength of the concrete column.
... Responsible Editor: Seonho Cho * Gennaro Senatore gennarosenatore@gmail.com for bridges (Rodellar et al. 2002), active bracing and columns (Reinhorn et al. 1992;Weidner et al. 2018) for buildings, as well as semi-active variable stiffness and damping structural joints (Wang et al. 2020a;. Active shape control has also been investigated for deployable structures, space cranes, and antennas (Tibert 2002;Veuve et al. 2015). ...
This paper gives a new formulation to design adaptive structures through total energy optimization (TEO). This methodology enables the design of truss as well as tensegrity configurations that are equipped with linear actuators to counteract the effect of loading through active control. The design criterion is whole-life energy minimization which comprises an embodied part in the material and an operational part for structural adaptation during service. The embodied energy is minimized through simultaneous optimization of element sizing and actuator placement, which is formulated as a mixed-integer nonlinear programming problem. Optimization variables include element cross-sectional areas, actuator positions, element forces, and node displacements. For tensegrity configurations, the actuators are not only employed to counteract the effect of loading but also to apply appropriate prestress which is included in the optimization variables. Actuator commands during service are obtained through minimization of the operational energy that is required to control the state of the structure within required limits, which is formulated as a nonlinear programming problem. Embodied and operational energy minimization problems are nested within a univariate optimization process that minimizes the structure’s whole-life energy (embodied + operational). TEO has been applied to design a roof and a high-rise adaptive tensegrity structure. The adaptive tensegrity solutions are benchmarked with equivalent passive tensegrity as well as adaptive truss solutions, which are also designed through TEO. Results have shown that since cables can be kept in tension through active control, adaptive tensegrity structures require low prestress, which in turn reduces mass, embodied energy, and construction costs compared to passive tensegrity structures. However, while adaptive truss solutions achieve significant mass and energy savings compared to passive solutions, adaptive tensegrity solutions are not efficient configurations in whole-life energy cost terms. Since cable elements must be kept in tension, significant operational energy is required to maintain stable equilibrium for adaptation to loading. Generally, adaptive tensegrity solutions are not as efficient as their equivalent adaptive truss configurations in mass and energy cost terms.
... demonstrator in a current research project dealing with such adaptive structures. 7 The shape transition is realized by different types of actuators, from piezoelectric or electroactive polymer actuators, [8][9][10] up to shape-memory alloys, 11 which are usually controlled by optimal control algorithms. 12 The aforementioned types of adaptive structures are characterized by the fact that the individual states differ only by minor changes in geometry such that geometrically linear analyses are sufficient. ...
Adaptive structures are characterized by their ability to adjust their geometrical and other properties to changing loads or requirements during service. This contribution deals with a method for the design of quasi‐static motions of structures between two prescribed geometrical configurations that are optimal with regard to a specified quality function while taking large deformations into account. It is based on a variational formulation and the solution by two finite element discretizations, the spatial discretization (the standard finite element mesh) and an additional discretization of the deformation path or trajectory. For the investigations, an exemplary objective function, the minimization of the internal energy, integrated along the deformation path, is used. The method for motion design presented herein uses the Newton‐Raphson method as a second‐order optimization algorithm and allows for analytical sensitivity analysis. The proposed method is verified and its properties are investigated by benchmark examples including rigid body motions, instability phenomena, and determination of inextensible deformations of shells.
... The first category accounts for truss structures in which individual single bars are actuated (contracted or extended). In Weidner et al. (2018), a large-scale prototype of an adaptive high-rise building is presented, in which the deformations and vibrations of the structure can be reduced by active columns and bracing elements. In another example, displacement control has been used to completely compensate for the deflection of an adaptive truss with electrical linear actuators (Senatore et al., 2018). ...
The rapidly growing world population is a great challenge for the building industry. Due to the impending scarcity of resources, it is not possible to provide the growing mankind with sufficient living and work places and infrastructure with current construction methods. For wide-spanning beams and slabs, the decisive design criteria are mainly determined by deformations rather than stresses, since deflections must be limited. This leads to structural elements, which are not fully utilized. However, if the deformations can be reduced, significant material savings can be achieved. Sensors, actuators, and a control unit enable components subjected to bending to adapt to high but rare loads. This article presents a solution that allows beams to react actively to loads by use of integrated actuators. The newly developed integrated hydraulic actuators allow the structure to react specifically to a wide range of load cases, by adjusting the internal hydraulic pressure. This is a clear advantage in load-bearing systems because there is often no dominant load case. This internal actuation concept is a new approach, as previous adaptive structures either have externally added actuators or are composed of truss structures in which single bars are actuated. In this paper, the concept is explained analytically, simulated with the finite element method and validated experimentally.
... The structure will be a twelve story building with 36 m height covering a square base with side length of 4.7 m, detailed information is given by Weidner et al. (2018). The scale model investigated in this contribution is 18 times smaller, leading to a height of 2 m and a square ground base of 0.26 × 0.26 m (see Figure 2B). ...
Adaptive structures are conventional truss structures that are equipped with sensors, actuators, and a control unit. This offers the opportunity of reacting and adapting to external loads but raises nontrivial issues. When actuators are placed optimally within a structure, they can be individually integrated either parallel to or in series with elements of the original passive structure. Additionally, some of the elements might be tension-only elements and thus have to be treated as nonlinear, as their stiffness depends on the stress within the element itself. Input constraints naturally arise for actuators, e. g., due to the maximum pressure limit of a hydraulic system and displacement limits of the actuators. We present modeling approaches for an add-on inclusion of these different types of actuators in an existing finite-element model of a passive structure. We place special focus on the ability of the model to reproduce the correct behavior in case of an actuator reaching its displacement constraint within a tension-only element. When such an adaptive structure is subject to static loads, e. g., wind loads, it is required to respond using its actuators to keep the structure within given safety and comfort limits. These limits can be expressed as state constraints. We present a method for optimally compensating these static loads under the given input and state constraints along with experimental results on a scale model of an actual high-rise building. An important aspect regarding adaptive structures is that of their behavior in case of actuator faults. An obvious result is that a structure's performance degrades, and the controller needs to recognize faults and deal with it properly. Assuming a diagnosed actuator fault, we present results illustrating the performance degradation. The designed controller can reconfigure and reinitialize itself. The performance with and without applied reconfiguration to the nominal case is compared.
... An adaptive truss structure high-rise is being constructed on the campus of the University of Stuttgart in the scope of the collaborative research center CRC1244 [14]. It is intended for demonstrating the concept of actuated truss structures to a larger audience. ...
In the context of control of smart structures, we present an approach for state estimation of adaptive buildings with active load-bearing elements. For obtaining information on structural deformation, a system composed of a digital camera and optical emitters affixed to selected nodal points is introduced as a complement to conventional strain gauge sensors. Sensor fusion for this novel combination of sensors is carried out using a Kalman filter that operates on a reduced-order structure model obtained by modal analysis. Signal delay caused by image processing is compensated for by an out-of-sequence measurement update which provides for a flexible and modular estimation algorithm. Since the camera system is very precise, a self-tuning algorithm that adjusts model along with observer parameters is introduced to reduce discrepancy between system dynamic model and actual structural behavior. We further employ optimal sensor placement to limit the number of sensors to be placed on a given structure and examine the impact on estimation accuracy. A laboratory scale model of an adaptive high-rise with actuated columns and diagonal bracings is used for experimental demonstration of the proposed estimation scheme.
... A demonstrator high-rise will also be erected on the campus of the University of Stuttgart. Details are presented in Weidner et al. (2018). Apart from the aforementioned challenges in the design of the load-bearing structure, the research center conducts work on adaptive facades and adaptivity in the field of building physics. ...
Taking advantage of adaptivity in the field of civil engineering is a subject of ongoing research. Integration of adaptive elements in load-bearing structures is already well-established in many other engineering fields, albeit mostly for different purposes than withstanding predominantly static loads. Initial investigations have demonstrated potential for substantial material and energy savings also in the field of civil engineering, especially for high-rise buildings and wide-span structures, such as roofs or bridges. Adaptive civil structures show promise in tackling current challenges arising from emissions and shortages of materials. In this study, we compare the possible minimum-weight designs for different actuator placement approaches and for different structural topologies that satisfy various constraints for high-rise buildings. We use case studies as illustrative examples to show which advantages and disadvantages can be expected from a specific design. The overarching aim is to learn how truss and beam structures should be designed to perform well as adaptive structures.
... demonstrator in a current research project dealing with such adaptive structures. 7 The shape transition is realized by different types of actuators, from piezoelectric or electroactive polymer actuators, [8][9][10] up to shape-memory alloys, 11 which are usually controlled by optimal control algorithms. 12 The aforementioned types of adaptive structures are characterized by the fact that the individual states differ only by minor changes in geometry such that geometrically linear analyses are sufficient. ...
Adaptive structures are characterized by their ability to adjust their geometrical and other properties to changing loads or requirements during service. This contribution deals with a method for the design of quasi-static motions of structures between two prescribed geometrical configurations that are optimal with regard to a specified quality function while taking large deformations into account. It is based on a variational formulation and the solution by two finite element discretizations, the spatial discretization (the standard finite element mesh) and an additional discretization of the deformation path or trajectory. For the investigations, an exemplary objective function, the minimization of the internal energy, integrated along the deformation path, is used. The method for motion design presented herein uses the Newton-Raphson method as a second order optimization algorithm and allows for analytical sensitivity analysis. The proposed method is verified and its properties are investigated by benchmark examples including rigid body motions, instability phenomena and determination of inextensible deformations of shells.
... In civil engineering, active control has been mostly implemented for vibration suppression of structures under extreme loading events [1][2][3]. Different systems including active bracings and columns for buildings and active cable-tendons for bridges have been studied [4][5][6][7]45]. Shape control has been investigated to reduce the static as well as the dynamic response of tensegrity structures [8][9][10][11][12], to improve airplane maneuverability through morphing wings [13][14][15] as well as for the control of direct daylight in buildings [16]. ...
This paper presents a new All-In-One (AIO) implementation of an existing formulation to design adaptive structures through Total Energy Optimization (TEO). The method implemented in previous work is a nested optimization process, here named TEO-Nested. Numerical simulations and experimental testing have shown that the TEO-Nested method produces structures that embody and use significantly lower energy compared to passive designs. However, TEO-Nested does not guarantee solution optimality. The formulation presented in this paper is an AIO optimization based on Mixed Integer Nonlinear Programming (MINLP), here named TEO-MINLP. Element cross-section areas, internal forces, nodal displacements and control commands are treated as continuous variables while the actuator positions as binary variables. Stress and displacement limits are included in the optimization constraints. Case studies of reticular structures are employed to benchmark the solutions with those produced by the TEO-Nested method. Results have shown that both formulations produce similar solutions which are only marginally different in energy terms thus proving that the TEO-Nested method tends to converge to optimal (local) solutions. However, the computation time required by TEO-Nested is only a fraction of that required by TEO-MINLP, which makes the former more suitable for structures of complex layout that are made of many elements.
... An adaptive truss structure high-rise is being constructed on the campus of the University of Stuttgart in the scope of the collaborative research center CRC1244 [14]. It is intended for demonstrating the concept of actuated truss structures to a larger audience. ...
In the context of control of smart structures, we present an approach for state estimation of adaptive buildings with active load-bearing elements. For obtaining information on structural deformation, a system composed of a digital camera and optical emitters affixed to selected nodal points is introduced as a complement to conventional strain gauge sensors. Sensor fusion for this novel combination of sensors is carried out using a Kalman filter that operates on a reduced-order structure model obtained by modal analysis. Signal delay caused by image processing is compensated for by an out-of-sequence measurement update which provides for a flexible and modular estimation algorithm. Since the camera system is very precise, a self-tuning algorithm that adjusts model along with observer parameters is introduced to reduce discrepancy between system dynamic model and actual structural behavior. We further employ optimal sensor placement to limit the number of sensors to be placed on a given structure and examine the impact on estimation accuracy. A laboratory scale model of an adaptive high-rise with actuated columns and diagonal bracings is used for experimental demonstration of the proposed estimation scheme.
... Based on the findings from the Stuttgart Smart Shell, albeit with the aim of applying the concept of ultralightweight construction both to a larger scale and a different building system, the CRC 1244 is currently realizing an experimental high-rise building ( Fig. 1) which is to be deployed by the end of 2019 [11]. It presents a 36.5 meters high adaptive steel truss structure with an external staircase and comprises 12 floors of 5x5 meters each. ...
Conceiving buildings as adaptive architectural systems constitutes a promising strategy for meeting the increasing economic, ecological and programmatic demands placed on the built environment. This approach has so far been primarily investigated in the context of small-scale or uninhabitable structures. The concept of adaptive load-bearing structures, however, presents a strategy that allows tapping the potentials of adaptivity in the context of large-scale architecture. Moreover, it enables-and even requires-the development of genuinely adaptive structural morphologies beyond prevailing typologies. This, in turn, opens up hitherto unknown opportunities for architectural design. Informed by the participation in the design of an adaptive high-rise building, the research presented proposes an integrative design process, on the basis of agent-based computational design tools, that enables architects to interactively explore the architectural design space of adaptive structures within interdisciplinary design teams.
Purpose
Adaptive load-bearing structures pursue the approach of saving mass within a load-bearing structure by adding external energy, thus saving materials and resources. This paper provides an overview of current research developments and shows some examples of existing prototypes.
Design/methodology/approach
First, basic terms and definitions from the research field of adaptive structures are introduced. After a brief historical insight, the numerical methods and prototypes used are presented as examples. The paper concludes with a summary of the state-of-the-art and open questions.
Findings
The current state of the art shows that the idea of adaptive structures offers great potential for more sustainability and resource efficiency in the construction industry. However, it also shows that research is still at the basic stage and that there are still some gaps in research.
Originality/value
The implementation of adaptive load-bearing structures is just one of many different approaches to greater sustainability in the construction sector. The issue of adaptive structures is a highly interdisciplinary field of research. The following paper is a literature review intended to summarize and critically evaluate the state-of-the-art research in this field. In the final section, some open questions are addressed, indicating that this research topic is still evolving.
Floor slabs comprise the majority of the mass of a building. One approach to reducing the use of materials is adaptive structures, in which external forces are counteracted by internal actuation. In the development of suitable actuation and associated actuator concepts for individual structural elements, such as floor slabs, there is a strong mutual influence between the actuation and actuator concept, meaning a clear separation between the tasks of the disciplines involved is not possible. Rather, a tight coordination as well as the identification of the mutual influence during the development process is necessary. A case study is used to analyze the dependencies for actuation and actuator concept development and to present them graphically. A condensation of the results results in a first approach for the interdisciplinary development of adaptive structural elements.
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Geschossdecken umfassen den Großteil der Masse eines Gebäudes. Ein Ansatz zur Reduktion des Materialeinsatzes sind adaptive Tragwerke, bei denen durch innere Aktuierung den äußeren Einwirkungen entgegengewirkt wird. Bei der Entwicklung geeigneter Aktuierungs- und dazugehöriger Aktorkonzepte für einzelne Tragwerkselemente, wie z. B. Geschossdecken, zeigt sich eine starke gegenseitige Beeinflussung zwischen beiden Konzeptbereichen, weshalb eine scharfe Abgrenzung der Aufgaben der beteiligten Disziplinen nicht gelingt. Es ist vielmehr eine sehr enge Abstimmung sowie die Identifikation der gegenseitigen Beeinflussung während des Entwicklungsprozesses notwendig. An einem Fallbeispiel werden die Abhängigkeiten für die Aktuierungs- und Aktorkonzeptentwicklung analysiert und grafisch aufgearbeitet. Durch eine Kondensation der Ergebnisse ergibt sich ein erster Ansatz für die interdisziplinäre Entwicklung adaptiver Tragwerkselemente.
High-rise structures can efficiently provide living space in urban areas with high density population since they require a comparatively smaller footprint than low-rise structures. This aspect is important particularly considering world population growth and urbanization trends. However, the structural mass required for high-rise structures increases nonlinearly as the structure becomes taller and more slender to the extent that resource and emission efficiency decrease compared to low-rise structures. In the context of climate change and impending resource scarcity, new material and emission efficient building technologies must be developed. One such approach are adaptive load-bearing structures, i.e., structures that can adapt and optimize their load-bearing behaviour under changing loading conditions. This paper studies the adaptability of two idealised high-rise structures to static lateral loads by means of actuation influence matrices. The high-rise structures are assembled from basic bracing modules of a truss and frame. A reduction of deformations is proposed as primary control objective and two actuation concepts are derived from the passive load-bearing behaviour of the high-rises. The actuation concept for truss structures achieves a stress-free deformation control.
New approaches and technologies are needed to counter the effects of climate change and mitigate the depletion of material resources. A possible solution are adaptive load-bearing structures, i.e., structures that are equipped with sensors, actuators and control units, enabling the structure to optimise its current stress state. This requires new research regarding the overall structural design of material- and emission-efficient adaptive structures. Existing approaches employ sensitivity matrices or optimality criteria in optimization formulations to design adaptive load bearing structures and discuss the quality of the design based on the results. This paper presents the method of actuation influence matrices, which are a type of sensitivity matrix that can be used quantify the inherent adaptability of a structure. The aim is to develop an intuitive design method for adaptive structures. After a brief derivation of the influence matrices, the methodology is illustrated using three basic bracing systems – a truss, a frame and a diagonally braced frame – as example, demonstrating the relationship between structural topology and inherent adaptability. While the assessment of an adaptive structure’s quality depends on the specific use case and control objective, it is proposed that truss systems are good candidates for adaptive structures due to their inherent adaptability.
Digitale Plattformen haben die Mechanismen vieler Märkte im Consumer Bereich grundlegend verändert. Durch die fortschreitende Digitalisierung, steht auch die Industrie nun an der Schwelle zur Plattformökonomie. Der Einstieg ins Plattformgeschäft ist jedoch für viele Unternehmen mit großen Herausforderungen verbunden. Digitale Plattformen folgen einer völlig anderen Geschäftslogik als klassische, lineare Geschäftsmodelle. In vielen Unternehmen mangelt es daher an Know-how und Erfahrung im Plattformgeschäft. Insbesondere die Entwicklung eines schlüssigen Geschäftsmodells ist ein Erfolgsfaktor in der frühen Phase der Geschäftsplanung. In diesem Beitrag stellen wir eine Methode zur Entwicklung und Bewertung IoT-basierter Plattform-Geschäftsmodelle vor. Ausgehend von einer Plattformidee gilt es, in einem ersten Schritt ein Geschäftsmodell-Konzept zu entwickeln. Im zweiten Schritt werden zur Detail-Entwicklung drei Partialmodelle erarbeitet. Im dritten Schritt erfolgt schließlich die wirtschaftliche und die Risikobewertung des Geschäftsmodells. Die Ergebnisse werden in einer Management Summary zusammengefasst und dienen als Entscheidungsgrundlage für die Umsetzung des Vorhabens.
Nowadays facade designers are challenged by a considerable number of performance requirements challenge, among others the continuing search for more transparency, often in combination with restrictive energy requirements or with extreme loading conditions such as bomb blasts: Four selected projects presented in this paper demonstrate how these challenges can be successfully addressed in the design process. However, despite the sophisticated engineering tools available nowadays, the article also shows where (and why) more innovation and research work is needed in the future. These innovations are required to allow for significant reductions in the consumption of resources and in the production of emissions and other forms of waste by the building industry. One way to tackle this challenging task is the use of more dynamic, adaptive facades, which are able to react to changes in environmental conditions and in user comfort requirements. Even if this approach requires a certain input of energy and a higher degree of complexity, it is expected to substantially contribute to a more sustainable use of resources in the future.
Glasfassaden spielen in der modernen Architektur eine zentrale Rolle. Sie öffnen den Blick nach außen und bringen Tageslicht nach innen. Diese Transparenz bringt aber auch verschiedene bauphysikalische und energetische Herausforderungen mit sich, denen man auf unterschiedliche Weise begegnen kann. Verschiedene Technologien können dabei helfen, klimaangepasste und ressourcenschonende Fassaden zu planen und zu bauen: Während der Planungsphase sind Simulationen und präzise Modellierungsstrategien ein wichtiges Werkzeug; eine dynamische Anpassungsfähigkeit der Fassade hinsichtlich ihrer Transparenz und ihrer bauphysikalischen Eigenschaften könnte in Zukunft einen weiteren wichtigen Schritt Richtung Ressourcen- und Energieeffizienz bedeuten. Der vorliegende Artikel präsentiert ausgewählte Forschungsansätze und einige aktuelle Projektbeispiele, die aufzeigen, wie nachhaltige Fassadensysteme in der Zukunft aussehen könnten.
Sustainable facades: case studies in research and praxis. Glass facades play an important role in modern architecture: they open the view to the outside and let natural light inside. Their transparency entails certain energetic challenges, which can be addressed in different ways. Technologies can support the design process, in order to build sustainable facades and optimize overall use of resources. Today simulation and modelling software are already a useful tool during the design phase; in the future adaptive facade systems could provide answers to the quest for more energy and resource efficiency. This paper presents recent research work as well as innovative case studies, which show a variety of answers to the demand for more sustainable facades.
The increasing penetration of renewable energy sources (RESs) and the inherent volatility in demand profiles have added another layer of complexity to the management of energy resources in modern active buildings (ABs). Yet, three challenges have been neglected in previous studies: (1) There is no universal systematic method for identifying an AB’s general stochastic model; (2) No research has been conducted on the reliability-based design optimization for ABs’ energy supply; (3) Uncertain sources are not categorized based on their importance in regard to the optimization problem. This article aims to solve these challenges by proposing a probabilistic-based optimization approach for solving the reliability issue of energy supply in buildings with on-site renewable energy sources (RESs), taking into account the uncertainty associated with photovoltaic (PV) production and demand fluctuations. The suggested framework seeks to reduce the overall costs of the system while ensuring high energy supply reliability. The proposed methodology, when applied to a real-world case study, demonstrates a 60% increase in reliability of energy supply as compared to typical deterministic methodologies.
Der anhaltende Wunsch vieler Architekten und Bauherren nach mehr Transparenz ebenso wie viele andere Anforderungen an Effizienz, Nutzerkomfort, Nachhaltigkeit etc. stellen die Fassadenplaner vor immer neue Herausforderungen. Bei Entwurf und Planung muss eine Vielzahl an Parametern berücksichtigt werden. Anhand von vier ausgewählten Projekten wird im vorliegenden Aufsatz aufgezeigt, wie dies am besten gelingt. Trotz ausgeklügelter konstruktiver Lösungen und der Verwendung von innovativen digitalen Werkzeugen stellt sich dabei aber auch die Frage, ob eine moderne Fassade nicht anpassungsfähiger sein sollte, um eine stärkere Interaktion zwischen Menschen und Hüllen zu ermöglichen. Dadurch könnte in Zukunft material- und ressourceneffizienter gebaut werden, ohne auf Komfort verzichten zu müssen. Zwei ausgewählte Forschungsprojekte, die ebenfalls im Nachfolgenden skizziert werden, zeigen auf, wie sich der Fassadenbau durch mehr Adaptivität in den kommenden Jahrzehnten weiter entwickeln könnte.
Glass facades: challenges and potentials in the 21st century. Several performance requirements challenge facade designers nowadays, among others the continuing search for more transparency: this and several parameters have to be considered in the design process, as shown in four selected recent projects. Despite sophisticated engineering work and the use of innovative digital tools, it has to be questioned if modern facades are as yet adaptive enough: a stronger interaction with the user should be the objective. This way it could be possible in the future to build with fewer resources, but without reducing standard comfort levels. Two selected research projects exemplify this approach, thus showing how the facade sector may evolve in the coming decades.
This paper reports on experimental testing that was carried out on a prototype adaptive structure designed to counteract the effect of loading through controlled large shape changes. The prototype is 6.6 m truss equipped with 12 linear actuators which has been designed through a method that combines geometry optimization and non-linear shape control. The structure is designed to adapt into target shapes that are optimal under each load case. Shape adaptation is achieved through controlled length changes of linear actuators that strategically replace some of the structure elements. The actuator placement is optimized to control the structure into the required target shapes. This way, material utilization is maximized and thus material energy embodied is reduced. Experimental testing is carried out to verify numerical findings and investigate the feasibility of the design method. The applied load is inferred through a classification model based on supervised learning. A control algorithm based on a linear-sequential form of geometry optimization is proposed. Experimental results show that this method successfully allows for real-time shape adaptation to achieve stress homogenization under various loading conditions.
Die „Große Beschleunigung“ bei Bevölkerungszahlen, klimaschädlichen Emissionen, Wasserverbrauch und vielem anderen stellt die gesamte Menschheit vor große Herausforderungen. Dies trifft besonders auf das Bauschaffen zu. Es gilt, zukünftig für mehr Menschen mit weniger Material emissionsfrei zu bauen. Hierfür muss unsere Art des Planens, Bauens und Nutzens von Bauwerken neu gedacht und neu konzipiert werden. Auf der bautechnischen Seite bedeutet dies die konsequente flächendeckende Umsetzung von Leichtbaustrategien. Zu diesen zählt neben dem klassischen Leichtbau und den Gradientenbauweisen auch das Bauen mit adaptiven Hüllen und Strukturen. Unter Adaptivität sind dabei unterschiedliche Veränderungen der Geometrie, der physikalischen Eigenschaften von einzelnen Bauteilen oder von ganzen Bauwerken zu verstehen. Durch Adaption können Spannungsfelder homogenisiert, Bauteilverformungen reduziert und bauphysikalische Verhalten von Bauteilen verändert werden. All dies verringert nicht nur den Materialbedarf, sondern liefert auch einen wesentlichen Beitrag zur Steigerung des Nutzerkomforts. Adaptivität im weiteren Sinne bezeichnet einen ganzheitlichen Ansatz, in dem die Anpassung sozialer, kultureller und räumlicher Erfahrungen sowie architektonischer und planerischer Handlungsweisen eng mit den technologischen Entwicklungen verknüpft wird. Die Zusammenführung dieser Perspektiven ist Anspruch des SFB, um ganzheitliche Lösungen für eine zukünftige gebaute Umwelt zu finden.
Adaptive skins and structures constitute an approach for reducing the immense material consumption in the construction of buildings, their energy demand and related emissions. Through the integration of sensor-actuator systems, conventional structures and skins become a controllable dynamic system, capable of reacting to different external influences. This approach demands an integral planning and design process with participants from various disciplines. The Collaborative Research Centre (CRC) 1244 entitled Adaptive Skins and Structures for the Built Environment of Tomorrow, involves, the research of specific processes and methods for the design and planning of adaptive buildings. In this paper, conventional approaches in architectural design and planning are analysed, providing the basis for the development of an improved process for adaptive buildings.
It is widely assumed that the “dense vertical city” is more sustainable than the “dispersed horizontal city.” This concept has certainly been a large factor in the unprecedented increase in the construction of tall buildings globally over the last few decades, especially in the developing world. The concentration of people in denser cities — sharing space, infrastructure, and facilities — is typically thought to offer much greater energy efficiency than the expanded horizontal city, which requires more land use, as well as a higher energy expenditure in infrastructure and mobility.
Though this belief in the sustainability benefits of ‘dense’ versus ‘dispersed’ living is driving the development of cities from Toronto to Tianjin and from Sau Paulo to Shanghai, the principle has rarely been examined at a detailed, quantitative level. Studies to date have been mostly based on large data sets of generalized data regarding whole-urban energy consumption, or large-scale transport patterns. Crucially, there are very few studies that also take into account a “quality of life” aspect to urban vs. suburban living, in addition to differences in energy use patterns.
Chicago, the city in which this research has taken place, is uniquely positioned for a study exploring density vs. sprawl from a sustainability point of view. The birthplace of the tall building and one of the main crucibles for experimentation in the typology in the century or more since then, Chicago also has an ever-growing suburban area that is typical of most US cities. And yet, again in line with many other cities around the world over the past decade or two, it has seen suburban growth alongside densification of its downtown area and a resurgence of people seeking high-rise urban living.
This research report offers a quantitative evaluation of long-held assumptions, and with sometimes surprising results. The ground-breaking study quantitatively investigates and compares the sustainability of people’s lifestyles in both urban and suburban areas from environmental and social perspectives, using detailed information directly collected from households and best available data from public resources. It fills significant research gaps in our knowledge of the sustainability of urban density compared to suburban sprawl. This is an indispensable resource for policy makers, developers, urban planners, architects, utilities, and anyone else with a stake in shaping the future of the built environment.
There has been a long-standing debate about whether urban living is more or less sustainable than suburban living, and quality of life (QoL) is one of several key measures of the social sustainability of residential living. However, to our knowledge, no study to date has examined life satisfaction among residents of downtown high-rise living compared to residents living in suburban low-rise housing. Further, very few studies have utilized building or neighborhood-scale data sets to evaluate residents’ life satisfaction, and even fewer have controlled for both individual and household-level variables such as gender, age, household size, annual income, and length of residence, to evaluate residents’ life satisfaction across different living scenarios. Therefore, the goal of this study was to investigate residents’ satisfaction with their place of residence as well as overall life in general via surveys of individuals living in existing high-rise residential buildings in downtown Chicago, IL, and in existing low-rise residential buildings in suburban Oak Park, IL. Over 1500 individuals were contacted directly, resulting in over 500 responses. The number of fully completed responses for this study was 177, including 94 from residents of four downtown high-rise buildings and 83 from residents in suburban low-rise homes. Residents living in downtown high-rise buildings had significantly higher life satisfaction scores than residents living in suburban low-rise homes when controlling for demographic differences; however, the differences were small, as housing type explained less than 5% of the observed variance in life satisfaction outcomes. The research also evaluated five life satisfaction domains including travel, accessibility, social interaction, safety, and overall residential environment (ORE). In all cases, residents of the downtown high-rises reported higher satisfaction levels, although the scores on all these five satisfaction domains reported from both urban scenarios were very high. Moreover, all five satisfaction domains were highly associated with each other, and accessibility and safety were found as the strongest predictors of ORE for individuals.
Significance
A large part of all primary materials extracted globally accumulates in stocks of manufactured capital, including in buildings, infrastructure, machinery, and equipment. These in-use stocks of materials provide important services for society and the economy and drive long-term demand for materials and energy. Configuration and quantity of stocks determine future waste flows and recycling potential and are key to closing material loops and reducing waste and emissions in a circular economy. A better understanding of in-use material stocks and their dynamics is essential for sustainable development. We present a comprehensive estimate of global in-use material stocks and of related material flows, including a full assessment of uncertainties for the 20th century as we analyze changes in stock-flow relations.
Adaptive structures in civil engineering are mechanical structures with the ability to modify their response to external loads. Actuators strongly affect a structure’s adaptivity and have to be placed thoughtfully in the design process to effectively compensate external loads. For constant loads, this property is introduced as steady-state disturbance compensability. This property can be linked to concepts from structural engineering such as redundancy or statical indeterminacy, thus representing an interdisciplinary approach. Based on the disturbance compensability matrix, a scalar performance metric is derived as quantitative measure of a structure’s ability to compensate the output error for arbitrary constant disturbances with a given set of actuators. By minimizing this metric, an actuator configuration is determined. The concept is applied to an example of a truss structure.
Mechatronische Systeme entstehen durch Integration von vorwiegend mechanischen und elektronischen Systemen sowie zugehöriger Informationsverarbeitung. Wesentlich ist dabei die Integration der mechanischen und elektronischen Elemente durch ihre räumliche Anordnung und durch ihre Funktionen sowie die Erzielung synergetischer Effekte. Die örtliche Integration erfolgt durch den konstruktiven Entwurf, die funktionelle Integration durch die Informationsverarbeitung und damit durch die Gestaltung der Software.
Das vorliegende Buch führt in den Aufbau und die Modellbildung mechatronischer Systeme in einer einheitlichen Form ein und stellt das Verhalten von mechanischen Bauelementen, elektrischen Antrieben, Maschinen, Sensoren, Aktoren und Mikrorechnern dar. Ziel dabei ist, ein bestimmtes Systemverhalten zu erreichen.
Die zweite Auflage enthält wesentliche Erweiterungen bei der Entwicklungsmethodik, bei mechanischen Komponenten, elektrischen Antrieben, Beispielen von Maschinenmodellen, Sensoren, hydraulischen und pneumatischen Aktoren und fehlertoleranten Systemen. Aufgabensammlungen ergänzen die einzelnen Kapitel.
We present ideas and concepts towards defining a common framework unifying abstract metrics in order to quantify key features of technical load-bearing structures and biological systems. Our aim is to transfer biological concepts to technical systems at this abstract level rather than on the basis of their outward appearance or actual functionality. This means that the biological concept generators for load-bearing structures do not have to be load-bearing structures themselves but may instead achieve rather different functionalities. We intend to carry out this transference by generalizing graph-based abstractions of both technical and biological worlds to allow comparisons to be made at an abstract level. We focus in particular on the intrinsically competing aims of optimality versus multi-functionality and robustness. In this review, we present initial attempts towards defining suitable quantitative measures for robustness to serve as a common ground for studying technical systems and biological systems simultaneously. We discuss generic properties of a ubiquitous signalling network motif and potential relationships to a minimal model for a robust truss structure. These case studies suggest that topological complexity can serve as a common source for a design that is insensitive to perturbations and thus robust in the measures of both worlds.
The paper discusses the construction of the world's first full-scale prototype of an adaptive shell structure. The 10m × 10m double-curved structure, consisting of a multi-layer wood laminate, has three freely positionable supports. High-speed, real-time positioning of the supports allows for the manipulation of stress fields within the shell as well as of vibrations and deformations of the structure. The paper focuses on the potentials of adaptivity for shell structures and the construction process of the prototype.
Das Entwerfen im Leichtbau ist die Suche nach dem Leichtestmöglichen. Es ist das Herantasten an das physikalisch und das technisch Machbare und damit auch das Arbeiten an den wissenschaftlichen Grenzen. Mit dem vom Autor entwickelten Ultraleichtbau kann man die Grenzen des Leichtestmöglichen weit hinausschieben. Neben der Reduktion des Materialverbrauchs auf ein bisher nicht für vorstellbar gehaltenes Minimum wird es im Ultraleichtbau auch möglich, Verformungen zu reduzieren und Schwingungen unter dynamischer Beanspruchung zu dämpfen – ein enormer Fortschritt, der sehr interessante Perspektiven für das Bauwesen eröffnet. Der vorliegende Artikel beschreibt zugrundeliegende theoretische Überlegungen und präsentiert diverse Experimentalbauten, die das Potential des Ultraleichtbaus eindrücklich vor Augen führen.
Ultralightweight Structures. The search for lightweight constructions is the search for boundaries. Designing the lightest possible constructions can be equated with feeling one’s way towards the limits of what is physically and technically possible. It is about the aesthetics and physics of the minimal, and it is about stepping across the dividing lines between scientific disciplines. Using the concept of Ultralightweight Structures developed by the author, it becomes possible to reduce the use of material to a minimum hihterto considered unachievable. Moreover, it leads to the reduction of distortions and helps to dampen vibrations – an enormous progress opening up interesting new perspectives for architecture. The present article describes the theoretical considerations underlying the concept of Ultralightweight structures and presents a selection of experimental structures demonstrating the potential of this new concept.
Der vorliegende Artikel gibt eine grundlegende Übersicht über adaptive Systeme. Dabei werden zunächst die elementaren Grundlagen vorgestellt und die Funktionsweisen adaptiver Systeme erläutert. Daran anschließend werden die sich bei der Einführung adaptiver Systeme in das Bauwesen ergebenden Möglichkeiten am Beispiel adaptiver Gebäudehüllen und adaptiver Tragwerke aufgezeigt.
Angesichts schrumpfender Ressourcen und der stetig zunehmenden Belastung unserer Umwelt durch Schadstoffe und zu deponierende Abfälle muss das Ziel im Bauwesen in einer erheblichen Neuorientierung der Konstruktionsweisen bestehen. Die gebaute Umwelt (Hochbau, Tiefbau, Infrastruktur) steht für ca. 35% des Energieverbrauchs, 35% der Emissionen, 50% des Ressourcenverbrauchs und – zumindest in Zentraleuropa – für mehr als 50% des Massenmüllaufkommens. Mittel‐ bis langfristig ist dies im Interesse einer nachhaltigen Bewahrung unserer Umwelt für die nach uns kommenden Generationen nicht mehr zu vertreten. Ziel muss sein, die permanente Entnahme von Rohstoffen aus der Natur stark zu reduzieren (langfristig auf Null) und gleichzeitig das Entstehen nicht anderweitig zu verwendenden Abfalls möglichst zu vermeiden. Ein recyclinggerechtes Konstruieren ist für das Erreichen dieser Ziele eine wichtige Voraussetzung. Ziel muss eine Kreislaufwirtschaft sein, bei der idealerweise nur die Ressourcen genutzt werden, die sich bereits vorher im Stoffkreislauf befanden. Um dies praktisch erreichen zu können, sind allerdings viele durchgreifende Veränderungen notwendig, die jetzt den entwerfenden und konstruierenden Ingenieur erreicht haben.
Reduction of weight and embodied energy in Highrise construction
The built environment (architectural engineering, civil engineering, infrastructure) stands for approx. 35% of the energy consumption, 35% of the emissions, 50% of the consumption of resources, and – that is to say in Central Europe – for more than 50% of the mass waste volume. In medium to long‐term considerations about a sustainable preservation of the environment and for the benefit of the coming generations this view can no longer be hold. In the light of dwindling resources and of the steadily increasing pollution of the environment by pollutants and by waste to be landfilled the target must consist in a radical re‐orientation – both with regard to the question, how we are building and with regard to the question, how we are using our built environment. We must succeed in drastically reducing the permanent withdrawal of natural resources from the nature (in the long term down to zero) and simultaneously in avoiding the development of non‐reusable waste. At the same time it will be necessary to produce the entire energy required for the built environment on the regenerative way. A recyclable design is an indispensable precondition for reaching these goals. The aim must be a circular economy with ideal use of resources which were already before integrated in the material cycle. Indeed this can in fact be reached with radical changes only.
Zukunftsfähiges Bauen, Zukunftsfähiges Bauen
- Henry Lehmann
- Christoph Stanetzky
Biomimetic Research for Architecture and Building Construction, Biologically‐Inspired Systems
- Debdas Paul
- Layla Koohi Fayegh Dehkordi
- Malte Scheven
- Manfred Bischoff
- Nicole Radde
Sustainable, Resource Efficient Cities – Making it Happen
- Camaren Peter
- Mark Swilling
at – automatisierungstechnik
- J. L. Wagner
- J. Gade
- M. Heidingsfeld
- F. Geiger
- M. Scheven
- M. Böhm
- M. Bischoff
- O. Sawodny
Einsparung von Grauer Energie bei Hochhäusern
- Hans Reinke
- Georg
Reinke, Hans Georg: Einsparung von Grauer Energie bei Hochhäusern. In: Beton-und
Stahlbetonbau Bd. 108 (2013), Nr. 6, S. 395-403
- Werner Sobek
Sobek, Werner: Ultraleichtbau: Ultraleichtbau. In: Stahlbau
Bd. 83 (2014), Nr. 11, S. 784-789
United Nations Environment Programme: Sand, rarer than one thinks -UNEP global environmental alert service
UNEP, United Nations Environment Programme: Sand,
rarer than one thinks -UNEP global environmental alert service: March, 2014 (2014)
University of Stuttgart Institute for System Dynamics Waldburgstraße 17/19 70563 Stuttgart Germany julia
- Julia Wagner
- M Sc
Julia Wagner, M.Sc.
University of Stuttgart
Institute for System Dynamics
Waldburgstraße 17/19
70563 Stuttgart
Germany
julia.wagner@isys.uni-stuttgart.de
Oliver Sawodny University of Stuttgart Institute for System Dynamics Waldburgstraße 17/19 70563 Stuttgart Germany sawodny@isys
- Prof
- Dr
Prof. Dr.-Ing. Dr. H.c. Oliver Sawodny
University of Stuttgart
Institute for System Dynamics
Waldburgstraße 17/19
70563 Stuttgart
Germany
sawodny@isys.uni-stuttgart.de