A digital design process for shell structures

Over the last few decades, the design of freeform structures has undergone a radical change: powerful computational tools within parametric environment associated with digital fabrication techniques are pushing the boundaries of architecture towards bold solutions. The present work proposes a digital workflow for a shell in compression. The design process starts with the form-finding phase, which generates a hanging model. Through the interoperability of digital tools within parametric environment, optimization of the shape and structural analysis were carried out in order to investigate its behavior. The resulting surface is subject to tessellation, planarization of its cells that take into account fabrication constrains, and the 3D generation of panels composing the thickness of the structure. In order to accomplish an easier assembly process a hypothesis of a puzzle-like connection system was developed. The whole process provides a guidance for the design of freeform shell by the creation of a “customized” digital workflow implemented by digital fabrication techniques for the realization phase

A level set based method for fixing overhangs in 3D printing

3D printers based on the Fused Decomposition Modeling create objects layer-by-layer dropping fused material. As a consequence, strong overhangs cannot be printed because the new-come material does not find a suitable support over the last deposed layer. In these cases, one can add some support structures (scaffolds) which make the object printable, to be removed at the end. In this paper we propose a level set method to create object-dependent support structures, specifically conceived to reduce both the amount of additional material and the printing time. We also review some open problems about 3D printing which can be of interests for the mathematical community

Force-Driven Weave Patterns for Shell Structures in Architectural Design

The use of lightweight carbon fiber reinforced polymers (CFRP) in the discipline of architecture opens new possibilities for the construction of architectural components. CFRP has been explored mainly in engineering fields, such as aeronautics, automotive, ballistic and marine engineering. CFRP has also been explored in the discipline of architecture in the construction of shell structures because of its high strength-to-weight ratio and low-cost. There is, however, limited research on how structural analysis can be used to inform weave patterns for shell structures using CFRP. Further, previous research in the field has not performed physical structural tests to validate which force driven weave patterns perform best. This thesis addresses this gap by contributing a methodology for the creation of CFRP weave patterns from structural analysis and their validation through physical testing. Specifically, this thesis addresses three main problems: Firstly, understanding and analyzing the structural behavior of a shell structure through computation; Secondly, the creation of a weaving pattern of carbon fiber optimized for structural performance; the third part seeks to translate the digital model into fabricated prototypes. The results of this research show that force-flow derived patterns perform best. Consequently, force-flow is the information we should implement to create a more efficient force-driven weave pattern in shell structures. Adviser: David Newto

A scalable parallel finite element framework for growing geometries. Application to metal additive manufacturing

This work introduces an innovative parallel, fully-distributed finite element framework for growing geometries and its application to metal additive manufacturing. It is well-known that virtual part design and qualification in additive manufacturing requires highly-accurate multiscale and multiphysics analyses. Only high performance computing tools are able to handle such complexity in time frames compatible with time-to-market. However, efficiency, without loss of accuracy, has rarely held the centre stage in the numerical community. Here, in contrast, the framework is designed to adequately exploit the resources of high-end distributed-memory machines. It is grounded on three building blocks: (1) Hierarchical adaptive mesh refinement with octree-based meshes; (2) a parallel strategy to model the growth of the geometry; (3) state-of-the-art parallel iterative linear solvers. Computational experiments consider the heat transfer analysis at the part scale of the printing process by powder-bed technologies. After verification against a 3D benchmark, a strong-scaling analysis assesses performance and identifies major sources of parallel overhead. A third numerical example examines the efficiency and robustness of (2) in a curved 3D shape. Unprecedented parallelism and scalability were achieved in this work. Hence, this framework contributes to take on higher complexity and/or accuracy, not only of part-scale simulations of metal or polymer additive manufacturing, but also in welding, sedimentation, atherosclerosis, or any other physical problem where the physical domain of interest grows in time

Digital Tectonics as a Morphogenetic Process

p. 938-948Tectonics is a seminal concept that defines the nature of the relationship between architecture and its structural properties. The changing definition of the symbiotic relationship between structural engineering and architectural design may be considered one of the formative influences on the conceptual evolution of tectonics in different historical periods. Recent developments in the field of morphogenesis, digital media, theories techniques and methods of digital design have contributed a new models of integration between structure, material and form in digital tectonics. The objective of this paper is to propose and define tectonics as a model of morphogenetic process. The paper identifies and presents the manner in which theory and emerging concepts of morphogenesis as well as digital models of design are contributing to this new model. The paper first analyzes the historical evolution of tectonics as a concept and characterizes the emergence of theoretical framework reflected in concepts and terms related to morphogenesis.Oxman, R. (2010). Digital Tectonics as a Morphogenetic Process. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/695

A contemporary reinterpretation of Jorn Utzon’s material and technological innovations

Standardisation and the use of repetitive production processes was a key determinant of achievable forms in the industrial paradigm, impressively displayed in the Sydney Opera House. Today, complex non-repetitive, yet readily achievable, forms can be designed using computational design techniques that explicitly embedstructural, and fabrication logic from the beginning and which later enable the direct generation of instruction code for their accurate and efficient production viaComputer Numerically Controlled (CNC) machines.This paper builds on the thesis that Utzon's approach - the consideration of technology as an integral part of the design process - can give rise to novel structures which take advantage of the new technological situation. Furthering earlier research by the authors, a method for constructing a hybrid grid shellstructure combining timber and pre-cast concrete elements is proposed. The method is tested through the realisation of a pavilion in relation to the UtzonSymposium in Sydney in March 2014. The previous research shows how a grid shell structure of discrete concrete components can be produced with lasercut amorphous polyethylene terephthalate (PET) templates. The casting method minimises the material use for templates in relation to customisation. This paperconcerns realisation of a hybrid construction through integration of customised plywood components. Furthermore, the concrete construction is improved.Precision is improved through stabilisation of the template and modification of the geometry. Stability of the construction is achieved through new joint solutions. Reinforcement and joints are treated as a single element, thereby simplifying both production and assembly. In previous case studies scaffolding was amajor task, and this aspect is minimised with the method described here