A parametric investigation into the development of cold formed steel free form grid shells

In recent years, the adoption of parametric design approaches to geometric modelling allows to describe and investigate large complex systems with few variables [1]. Form finding techniques such as the force density and dynamic relaxation methods help in defining efficient free form structures [2]. There is therefore potential to design free form grid shells which can be optimized for basic parameters like support conditions, grid topology, load conditions, material and section properties. This work explores the possibility to use cold-formed steel section for free form shells, making advantage of their structural efficiency and versatility that allows the realization of light constructions. Three free form shells, having different geometries, configurations and grid topology, are investigated, and the viability of adopting cold formed steel members to create lightweight and stable grid shells through parametric modelling is analysed

Effects of different geometric patterns on free form gridshell structures

Gridshells are commonly known as structures with the shape and rigidity of a double curvature shell consisting of a grid, not a continuous surface. In recent decades, these structures have attracted significant attention. The impact of various geometric patterns on free form gridshell structures is investigated here to demonstrate the necessity of collaboration between structural and architectural characteristics in enhancing structure efficiency. To that goal, a framework is proposed where three shells are first designed, and then six geometric patterns are formed on them. The main factors for evaluation of gridshells are decreasing the steel weight as an economic index and decreasing the displacement as a structural index, also, finite element method is used for structurally analyzing the gridshells, and the generated gridshells are compared to each other based on the mentioned indices. For the optimization process, an approach is suggested to find the most optimum gridshell, then numerical results show the efficiency of the proposed alternative approach

Structural analysis in wood gridshell coverture

Orientadores: Nilson Tadeu Mascia, Cilmar Donizeti BasagliaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e UrbanismoResumo: Cascas em grelha de madeira também conhecidas como gridshells de madeira são estruturas especiais que combinam eficiência estrutural e arquitetura atraente. Este estudo visou pesquisar uma geometria eficiente de gridshell de madeira para a cobertura de um edifício em vias de uma recuperação estrutural. Foi analisada uma possível geometria final obtida a partir de simulações do efeito do peso próprio sobre uma malha por meio de software. Posteriormente, simulou-se a estrutura cargas por meio de um programa comercial de método dos elementos finitos ¿ ANSYS ¿ com o qual se pôde analisar a estrutura com geometria pré-definida em relação aos esforços solicitantes. Com tais resultados constatou-se a eficiência das gridshells como estruturas capazes de vencer grandes vãos com pequenos deslocamentos verticais. Por fim, foi realizado uma análise estrutural quanto ao efeito do vento sobre esse tipo de cobertura por meio de interação de fluido-estrutura com auxílio do software ANSYS e sua plataforma CFX, definindo-se uma metodologia para análise estrutural das gridshellsAbstract: Shells in grid of wood also known as gridshells made of wood are special structures that combine structural efficiency and attractive architecture. This study aimed to search an efficient geometry of wood gridshell to apply as coverage for a building that is ready to a structural recovery. It was analyzed a final possibility of geometry generated from own weight simulation over a mesh through the aid of a software. Afterwards, the structure was simulated with a commercial software of finite element method analysis (FEM Analysis) ¿ ANSYS ¿ which conducted to a final structural analysis of the same geometry predefined in terms of internal forces and moments. With these results, the good efficiency of gridshells as structures capable to reach large spans with small vertical displacements was noted. In the end, a wind effect structural analysis over this kind of coverage was obtained by the interaction of fluid and structure with the aid of the software ANSYS and its platform CFX, defining a methodology for structural analysis on gridshellsMestradoEstruturas e GeotécnicaMestre em Engenharia Civil830539/1999-9CNP

Bending-active plates : strategies for the induction of curvature through the means of elastic bending of plate-based structures

Commonly referred to as bending-active, the term has come to describe a wide variety of systems that employ the large defor-mation of their constituent components as a primary shape-forming strategy. It is generally impossible to separate the struc-ture from its geometry, and this is even more true for bending-active systems. Placed at the intersection between geometry, de-sign and engineering, the principle objective of this thesis is to develop an understanding of the structural and architectural po-tential of bending-active systems beyond the established typolo-gies which have been investigated so far. The main focus is set on systems that make use of surface-like elements as principle build-ing blocks, as opposed to previous and existing projects that pre-dominantly employed linear components such as rods and laths. This property places the analysed test cases and developed proto-types within a specific category of bending-active systems known as bending-active plate structures. The first chapters serve as a general introduction to the topic. An overview of relevant recent projects is presented in the introduction, followed by a discussion on the scope of research on bending-active structures. The following chapters lay the theoretical basis in terms of geometry of surfaces and mechanical behaviour of plates. This dual and complementary description serves as the necessary background to understand the limits and potential associated to the deformability of plate elements. The following chapter delves into the first of the two strategies developed as part of this research. Termed form conversion, this approach establishes a one-to-one relationship between the initial base surface and its bending-active discrete counterpart. The chapter proceeds with the presentation of a series of full-scale prototypes that were realised to test the validity of the form con-version approach. Geometrical and mechanical features are dis-cussed in the conclusion of the chapter. The second developed method, named integral approach, is pre-sented in the next section. This approach takes advantage of the inherent deformation properties of explicitly designed material patterns. The description of the method is followed by the presen-tation and discussion of the prototypes chosen to test the integral approach. Finally, the thesis concludes with a critical discussion of the presented approaches and a discussion on potential developments for future research