Free-form, form finding and anisotropic grid shell

p. 966-876The new geometrical developments open new perspectives for free-form design, making it possible to escape from planar triangular or quadrilateral discretizations. Recent advances in theory algorithms allow for the discretization of any surface using only single curvature panels thus allowing the realisation of smooth double curvature glazed envelops of any form. Grid shell structures usually present a nearly in plane uniform behaviour, but previous realisations have shown that grid shells can be designed also according to an anisotropic inplane arrangement. The control of principal direction and the fine tuning of the stiffness of the different structural elements (arcs, cables etc.) is a tool for adjusting the form-finding thus controlling the resulting geometry. Moreover, the form-finding can also be performed without researching a constant stress (self weight); in this case an even wider range of forms become possible. These new geometrical and structural approaches have been coupled together and tested in re-designing, as a case study, the glazed roof of the Neumunster Abbey in Luxembourg. Such approach allowed for the conception of an efficient structure supporting a smooth double curvature glass skin, made out of only single curvature panels, perfectly coherent with the perimeter of the courtyard i.e. matching all the edges without any gaps.Baldassini, N.; Raynaud, J. (2010). Free-form, form finding and anisotropic grid shell. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/696

Interactive design exploration for constrained meshes

In architectural design, surface shapes are commonly subject to geometric constraints imposed by material, fabrication or assembly. Rationalization algorithms can convert a freeform design into a form feasible for production, but often require design modifications that might not comply with the design intent. In addition, they only offer limited support for exploring alternative feasible shapes, due to the high complexity of the optimization algorithm. We address these shortcomings and present a computational framework for interactive shape exploration of discrete geometric structures in the context of freeform architectural design. Our method is formulated as a mesh optimization subject to shape constraints. Our formulation can enforce soft constraints and hard constraints at the same time, and handles equality constraints and inequality constraints in a unified way. We propose a novel numerical solver that splits the optimization into a sequence of simple subproblems that can be solved efficiently and accurately. Based on this algorithm, we develop a system that allows the user to explore designs satisfying geometric constraints. Our system offers full control over the exploration process, by providing direct access to the specification of the design space. At the same time, the complexity of the underlying optimization is hidden from the user, who communicates with the system through intuitive interfaces

Low-Cost Double Curvature: Geometrical and Structural Potentials of Rectangular, Cold-Bent Glass Construction

The realization of doubly curved façades often requires large investments in fabrication equipment and produces additional waste through subtractive fabrication processes and non-reusable molds. In glass construction, elastic bending techniques can be used for small curvatures. This paper continues previous research of the authors on bending rectangular glass elements into irregularly curved panels. First, we analyze the stresses occurring in cold bent glass during assembly, thus defining a particlespring model which is able to compute approximate stresses in real-time during the bending procedure. In a second step, we compare the structural performance of the bent glass with that of flat panels using FE-analysis. Finally, we illustrate the implementations on multi-panel façade layouts. We analyze the dependencies between curvature, gap-tolerance and panelization. We present a method to minimize gap-tolerances by optimizing the distribution of surface curvature. Our results highlight the structural and geometrical potentials and possible applications for curved glass construction

All-glass shell scale models made with an adjustable mould

Ever since Lucio Blandini developed a doubly curved synclastic shell with adhesively bonded glass components, the concept of building a self-supporting glass-only shell has almost become within reach. In the current contribution a small-scaled experimental concept is presented of a self-supporting anticlastic all-glass shell scale model, created by means of an adaptable mould. First, different manufacturing parameters of relatively small shells are investigated, such as mould type, glass supporting system and dimensions, oven temperature and shell curvature. Next, an adjustable mould for the bending of glass is developed, built and tested. With this mould it is possible to make glass panels synclastic and anticlastic in a great variety of forms. With this new moulding technique we were able to create different prototypes. They are forming the basis an intended larger shell, composed of smaller segments. The objective is to join the latter by using fusing techniques, which result is completely transparent monolithic all-glass shells. Therefore, additional experiments have been performed to explore different variants of glass fusion techniques to be applied for double curved glass shells

Development and evaluation of mould for double curved concrete elements

The present paper describes a concept for a reconfigurable mould surface which is designed to fit the needs of contemporary architecture. The core of the concept presented is a dynamic surface manipulated into a given shape using a digital signal created directly from the CAD drawing of the design. This happen fast, automatic and without production of waste, and the manipulated surface is fair and robust, eliminating the need for additional, manual treatment. Limitations to the possibilities of the flexible form are limited curvature and limited level of detail, making it especially suited for larger, double curved surfaces like facades or walls, where the curvature of each element is relatively small in comparison to the overall shape

Wire mesh design

We present a computational approach for designing wire meshes, i.e., freeform surfaces composed of woven wires arranged in a regular grid. To facilitate shape exploration, we map material properties of wire meshes to the geometric model of Chebyshev nets. This abstraction is exploited to build an efficient optimization scheme. While the theory of Chebyshev nets suggests a highly constrained design space, we show that allowing controlled deviations from the underlying surface provides a rich shape space for design exploration. Our algorithm balances globally coupled material constraints with aesthetic and geometric design objectives that can be specified by the user in an interactive design session. In addition to sculptural art, wire meshes represent an innovative medium for industrial applications including composite materials and architectural façades. We demonstrate the effectiveness of our approach using a variety of digital and physical prototypes with a level of shape complexity unobtainable using previous methods

The development of a finite elements based springback compensation tool for sheet metal products

Springback is a major problem in the deep drawing process. When the tools are released after the forming stage, the product springs back due to the action of internal stresses. In many cases the shape deviation is too large and springback compensation is needed: the tools of the deep drawing process are changed so, that the product becomes geometrically accurate after springback. In this paper, two different ways of geometric optimization are presented, the smooth displacement adjustment (SDA) method and the surface controlled overbending (SCO) method. Both methods use results from a finite elements deep drawing simulation for the optimization of the tool shape. The methods are demonstrated on an industrial product. The results are satisfactory, but it is shown that both methods still need to be improved and that the FE simulation needs to become more reliable to allow industrial application

A research on a reconfigurable hypar structure for architectural applications

Thesis (Master)--İzmir Institute of Technology, Architecture, İzmir, 2013Includes bibliographical references (leaves: 102-108)Text in English; Abstract: Turkish and Englishxii, 108 leavesKinetic design strategy is a way to obtain remarkable applications in architecture. These kinetic designs can offer more advantages compared to conventional ones. Basic knowledge of different disciplines is necessary to generate kinetic designs. In other words, interdisciplinary studies are critical. Therefore, architect's knowledge must be wide-ranging in order to increase novel design approaches and applications. The resulting rich hybrid products increase the potential of the disciplines individually. Research on kinetic structures shows that the majority of kinetic structures are deployable. However, deployable structures can only be transformed from a closed compact configuration to a predetermined expanded form. The motivation of the present dissertation is generating a novel 2 DOF 8R reconfigurable structure which can meet different hyperbolic paraboloid surfaces for architectural applications. In order to obtain this novel structure; the integration between the mechanism science and architecture is essential. The term reconfigurable will be used in the present dissertation to describe deployable structures with various configurations. The novel reconfigurable design utilizes the overconstrained Bennett linkage and the production principals of ruled surfaces. The dissertation begins with a brief summary of deployable structures to show their shortcomings and their lack of form flexibility. Afterward, curved surfaces, basic terms in mechanisms and overconstrained mechanisms were investigated. Finally, a proposed novel mechanism which is inspired from the basic design principles of Bennett linkage and the fundamentals of ruled surfaces are explained with the help of kinematic diagrams and models