Romain Mesnil

Romain Mesnil
École des Ponts ParisTech · Civil Engineering

Dr. Ing., MEng
Assistant Professor, Manager of the Co-Innovation Lab

About

64
Publications
67,519
Reads
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525
Citations
Introduction
I am a structural engineer and researcher currently leading Build'in, a technological platform on construction automation and digital design. I closely collaborate with the Navier lab and its team Architected Materials and Structures. My personal research interest deals with generative design, discrete geometry, building systems and structural optimisation. You can find out more on our website www.buildin-enpc.fr
Additional affiliations
September 2014 - present
École des Ponts ParisTech
Position
  • Lecturer
Description
  • Lectures on various topics: - Building free form (intensive workshop on free-form construction) - Management of complex geometries - Conceptual structural design (up to 2019)
September 2012 - June 2013
Massachusetts Institute of Technology
Position
  • Master's Student
Education
January 2014 - February 2017
École des Ponts ParisTech
Field of study
  • Civil Engineering
August 2012 - June 2013
Massachusetts Institute of Technology
Field of study
  • Structural Engineering
September 2009 - June 2013
École des Ponts ParisTech
Field of study
  • Civil Engineering

Publications

Publications (64)
Article
Full-text available
The paper presents some results on the influence of the pre-stress induced by the erection method of elastic grid shells on their buckling capacity.It starts with the numerical methods and their validation with the study of a prebuckled arch. Then, a form-finding scheme using low-speed dynamics is used to generate automatically a family of elastic...
Chapter
Full-text available
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...
Article
Full-text available
The design of gridshells is subject to strong mechanical and fabrication constraints, which remain largely unexplored for non-regular patterns. The aim of this article is to compare the structural performance of two kind of gridshells. The first one is the kagome gridshell and it is derived from a non-regular pattern constituted of triangles and he...
Article
Full-text available
The aim of this paper is to present some innovative strategies for the design of plated shell structures. Fabrication constraints are carefully considered, as the obtained shapes are covered with planar quadrilateral facets only. Different corrugation strategies are investigated, and our method guarantees extension of the shape generation to comple...
Article
The Layer Pressing Strategy is widely used in large-scale concrete 3D Printing for its capacity to provide good control over the layer cross-section geometry and, consequently, the final overall printed element geometry. However, although layer pressing ensures exact positioning of the extruded layer upper surface, it may be at the origin of some d...
Conference Paper
In the face of dwindling resources and to reduce the construction sector’s carbon footprint, it is important to envisage the building’s end of life. It is necessary to consider buildings and their structures as elements that can be dismantled/disassembled for recycling/reuse. To address these issues, this work focuses on non-sequential assemblies t...
Article
The detection of anomalies is at the basis of any 3D printing control. In this paper, we propose a methodology for detection of anomalies based on computer vision. This methodology is composed of three modules: (1) image acquisition, (2) interlayer line and layer segmentation and (3) characterization of the local geometry and texture of the layers...
Article
This paper describes the Patching technique for building shells without wasteful support, thanks to 3D Printing technology. The method developed in this paper extends ancient vaulting techniques and decodes and formalises them into a design Grammar. Furthermore, numerical tools such as mesh pattern topology and shape topological skeleton are used t...
Poster
Full-text available
Various technologies of in-line reinforcement for extrusion-based 3D printing have been proposed in the recent years. With such techniques, knowledge of the dynamic rheological properties of the extruded material is a key point for several issues, such as its ability to properly impregnate reinforcement, and possibly to pull the reinforcement thank...
Chapter
The issue of reinforcement for 3D concrete printing has received considerable attention, as constructions have to comply with reliability principles and building standards. Here a specific process called Flow-Based Pultrusion for additive manufacturing (FBP), inspired by pultruded composite manufacturing and built on existing extrusion-based 3D pri...
Article
In the absence of a formwork, printable materials are expected to quickly increase their consistency in order to resist the self-weight of the structure being printed. Resolving this rheological requirement with the printing process is the key to successful printing. It is therefore necessary, from a material design, from a process design and from...
Article
Full-text available
Despite being a notoriously difficult task, efficient design of interlocking assemblies could greatly impact the construction sector and reduce its environmental footprint by helping in the design of demountable buildings and the reuse of structural members. While a growing research effort in this direction is being undertaken by the computer graph...
Preprint
Full-text available
We extend the problem of finding an optimal structure with maximum load-bearing capacity to the case of multiple materials. We first consider a reinforcement optimization case where the structure consists of a fixed background matrix material with given strength properties and optimize the reinforcement topology within this material. We discuss the...
Article
Full-text available
The present work addresses the problem of maximizing a structure load-bearing capacity subject to given material strength properties and a material volume constraint. This problem can be viewed as an extension to limit analysis problems which consist in finding the maximum load capacity for a fixed geometry. We show that it is also closely linked t...
Conference Paper
Full-text available
This study aims to design a topological interlocking structure which can be constructed without any formwork. According to studies, the cost of material and labour for formworks often consumes up to 50% of the total project cost (Hack et al)[1]. The construction industry, being one of the largest in the world economy with about 10 trillion USD (McK...
Conference Paper
This paper proposes a method to design non-sequential assembly for construction. Unlike interlocking assemblies, a non-sequential joint can be assembled with simultaneous movement of all parts and blocked only by its kinematic. Thanks to robotic manufacturing and advances in digital fabrication, we can produce complex joints which can be easily ass...
Conference Paper
Full-text available
The ancient vaulting techniques from drylands are an excellent inspiration for applying robotic 3D printing of a large-scale structure since they have solutions to fabricate earthen vaults in sustainable manners. The precision of the advanced hardware accompanied by software potential for managing vast and complex data opens a wide range of possibi...
Conference Paper
Full-text available
Despite being a notoriously difficult task, efficient design of interlocking assemblies could greatly impact the construction sector and reduce its environmental footprint by helping in the design of demountable buildings and the reuse of structural members. While a growing research effort in the direction of designing interlocking assemblies is be...
Article
Important developments in additive manufacturing with concrete have been achieved in the past decades. Yet, printed components usually do not comply with building standards or basic reliability principles, and are not commonly used as load-bearing components. A gap between research and practice exists and despite several attempts, off-the-shelf com...
Article
This paper introduces a novel rheological technique allowing for the assessment of printable materials yield stress at nozzle exit in the case of extrusion-based 3D printing. This technique is derived from the analysis of the specific gravity-induced non-Newtonian flow that takes place at nozzle exit, which is at the origin of the formation of mate...
Article
Full-text available
The patterns of many structural systems must fulfil a property of two-colourability to partition their elements into two groups. Such examples include top versus bottom layer of continuous beams in elastic gridshells, corrugated versus non-corrugated directions in corrugated shells or warp versus weft threads in woven structures. Complying with suc...
Article
Full-text available
This work aims at proposing a strategy for 3D-printing geopolymer composite structures at a half-meter scale, without using organic additives. An original printing device based on cartridges is developed and adapted to a 6-axis robot. The yield stress, working time and apparent Young modulus of the extruded material are measured. A devoted software...
Article
The vast majority of applications of extrusion-based concrete additive manufacturing deal with unreinforced mortar. The lack of reinforcement is a serious limitation for the industrial development of 3d printed concrete, because of the brittleness and lack of tensile strength of unreinforced mortar. In this paper, a new reinforcement method inspire...
Article
3d printing of cementitious material is a relatively new additive manufacturing process whose growing interest and fast development is mainly due to the digitalised manufacturing, allowing the disposition of material where it pleases. Yet, due to the properties of the fresh material and the difficulty to generate paths for the robots, the printed g...
Chapter
Full-text available
3d printing of cementitious material by pressing layers during the extrusion is a strategy that requires a rather low initial yield stress so the material can deform without cracking. It allows to perfectly control the height of the layer and gives freedom in the orientation of the printing head and of the layer allowing for a wider range of printa...
Chapter
The embodied energy of a building is not only but essentially determined by the quantity of material in its structure. Current fabrication techniques of optimised reinforced concrete (RC) structural elements have not proved sufficient economic competitiveness to be broadly accepted by the construction industry. This partly explains why the construc...
Chapter
Successful and efficient fabrication using robotic extrusion of cementitious materials mainly relies on the mastering of the printable material fresh state behavior. This paper tackles this aspect by introducing a novel rheological apparatus dedicated to the yield stress measurement at nozzle exit in extrusion-based manufacturing. It is based on th...
Chapter
Full-text available
This paper proposes a specific extrusion method for 3D printing of mortar called free deposition by the authors. It consists in letting a fine mortar flow through a moving nozzle above a support, here EPS foam. The aim is to obtain a regular lace, thus to avoid instability phenomena like coiling, and ensure a regular diameter, without stretching th...
Article
The paper presents new results about the geometry of topological interlocking masonries and some possibilities they present to build without formwork. Construction without the use of formwork may be an important issue concerning both productivity increase and decreasing of waste generated on a construction site. Due to the development of computatio...
Article
Full-text available
In a context of intense environmental pressure where the construction sector has the greatest impact on several indicators, the reuse of load-bearing elements is the most promising by avoiding the production of waste, preserving natural resources and reducing greenhouse gas emissions by decreasing embodied energy. This study proposes a methodology...
Conference Paper
Full-text available
Design of patterns involves meeting multiple objectives regarding architecture, engineering and construction. Form finding allows to explore the geometrical design space defined by the topol- ogy of the pattern, and to optimise a geometry to meet these objectives. This research introduces rule-based topology finding for the exploration of singulari...
Conference Paper
Full-text available
This paper describes an approach of a process-aware exploration of the design space of building components constructed by extrusion of cementitious material (or concrete 3d printing). In an attempt to broaden the geometries that are being printed today, and to build cantilevers, vaults and domes without using temporary support, we look back at cons...
Article
Full-text available
This paper introduces topology finding of patterns for shell structures such as beam grids for gridshells or voussoir tessellations for vaults, among others. The authors refer to topology finding, by analogy and in complement to form finding, as the design of the connectivity of these patterns in order to follow architectural, structural and constr...
Chapter
The aim of this paper is to discuss the dialectic form-finding of a complex timber structure based on an innovative structural system: shell-nexorade hybrids. Nexorades, also known as reciprocal frames are elegant structures that suffer from a relatively poor structural behavior due to in-plane shear and bending of the members. Introducing plates a...
Article
The difficulty to construct mechanically optimal shells may limit the use of structural optimisation in practice. The objective of this paper is to propose a new parametric representation of doubly curved shapes suited for structural optimisation of architectural shells that inherently considers fabrication constraints. We focus on a common constru...
Article
Full-text available
The aim of this article is to propose parameterization with planar facets of dome structures. The technique introduced in this paper starts from an input parameterization and creates a dual pattern with planar quadrilateral facets. The derivation of the analytical solution allows to link the method with the creation of meshes with planar hexagonal...
Conference Paper
Full-text available
The aim of this paper is to discuss the form-finding of an innovative structural system through the design and construction of a full-scale timber pavilion. Nexorades, or multi-reciprocal grids, are structures where members support each other along their spans. This structural principle allows simple assembly and connection details, but leads in co...
Conference Paper
Full-text available
This paper presents the design and fabrication of an innovative structure, spanning 6.5m with a structural thickness of 12cm. The structural system derives from nexorades, also called reciprocal frames by some authors, obtained by a novel form-finding method based upon translation of the edges. It also allows for the covering with planar facets if...
Conference Paper
Full-text available
p>By reinforcing the links between mechanics of materials, structural engineering and applied mathematics at a sufficiently high level, new paths may be explored and building innovations proposed, making complex structures more affordable constructions. Three main keys are explained and illustrated with examples. The first key is a deep knowledge o...
Article
Full-text available
The design of gridshells is subject to strong mechanical and fabrication constraints, which remain largely unexplored for non-regular patterns. The main technological constraints for glazed gridshells are related to the planarity of facets and the existence of torsion-free offsets. The authors propose indicators to evaluate a priori the quality of...
Article
Full-text available
Elastic gridshells are structures made of flat two-way grids which are deformed elastically before they are braced and which afterwards mechanically behave like continuous shells. Gridshells present some advantages in terms of manufacturing, lightness and time of assembly. Their covering remains however a technical issue. The present article propos...
Article
Full-text available
We introduce an intuitive method, called Marionette by the authors, for the modelling of free-form architecture with planar facets. The method takes inspiration from descriptive geometry and allows to design complex shapes with one projection and the control of elevation curves. The proposed framework achieves exact facet planarity in real-time, an...
Article
Full-text available
The aim of this paper is to introduce a bottom-up methodology for the modelling of free-form shapes in architecture that meet fabrication constraints. To this day, two frameworks are commonly used for surface modelling in architecture: NURBS modelling and mesh-based approaches. The authors propose an alternative framework callled generalised cyclid...
Thesis
Full-text available
The last decades have seen the emergence of non-standard architectural shapes. Designers find often themselves helpless with the geometrical complexity of these objects. Furthermore, the available tools dissociate shape and structural behaviour, which adds another complication. This dissertation takes the point of view based on invariance under geo...
Conference Paper
Full-text available
Elastic gridshells are structures made of flat two-way grids which are deformed elastically before they are braced and which afterwards mechanically behave like continuous shells. Gridshells present some advantages in terms of manufacturing, lightness and time of assembly. Their covering remains however a technical issue. The present article propos...
Conference Paper
Full-text available
This paper presents a new methodology for generating doubly-curved shapes covered with planar facets. The proposed method, called marionette method relies mainly on descriptive geometry, and it is shown that specifying appropriate projections, e.g. plane view and elevations, defines uniquely a free-form shape. This methodology is highly intuitive a...
Article
Full-text available
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 surf...