Bringing together experts from research and practice, Shell Structures for Architecture: Form Finding and Optimization presents contemporary design methods for shell and gridshell structures, covering form-finding and structural optimization techniques. It introduces architecture and engineering practitioners and students to structural shells and provides computational techniques to develop complex curved structural surfaces, in the form of mathematics, computer algorythms, and design case studies.
The larger intention of this research and the future research trajectory is to expand the conception of wood as a structural building material, encouraging its broader use both within Canada and in emerging markets. When architects and engineers desire a curved surface they should think of wood as the material that can create these new architectural forms. Shell, lapped, and folded plate structures using CLT show potential for spanning larger interior spaces such as those in gymnasiums, community centres, schools, churches general large entry spaces and circulation areas. They provide large column free spans, and are highly structurally efficient.
Contemporary design technology has given architects the ability to imagine and visualize complex structures to an extent that is currently beyond our ability to effectively fabricate and build. The described research is intended to mediate between the imagination of the designer and the current modes of construction; this project is part of a larger proposition to use wood as a sustainably sourced material that can be formed, curved and machined to create new digitally produced and tested formations. TimberShell creates prototypes for full-scale timber monocoque structures. Material computation affords us the ability to use the natural bending properties of wood to both bend components into shape and to create a robust load carrying structure once individual wood components are locked in by lamination. The geometry of the shell panel eliminates twisting. The research shows how doubly-curved timber shells that can be applied in either tension or compression. The panels can be used to create and cover spanning structures such as pools, gyms and auditoriums.
Compression tests were conducted on the glulam members under different eccentricities, including three cases of 0mm,50mm and 100mm respectively, to study the mechanical performance of the new assemblage joints in reticulated timber shells. The bending stiffness and bending capacity of joints were evaluated, at the same time, the influence of failure mode and the changes...
In this paper, possibilities and challenges of novel robotic manufacturing processes for segmented timber shells are presented and evaluated. This is achieved by comparing two newly developed construction systems for segmented plate structures: one system consisting of cross-laminated timber elements that are connected with crossing screws, and one system consisting of light-weight, hollow components with finger joints as well as bolted connections. Segmented timber shells are introduced as an emerging structural typology transitioning from applied research to the building industry, enabled by new developments in computational design and digital fabrication methods. Although the two construction systems share their underlying segmentation strategy, they differ in their joint design approach and ensuing fabrication complexity. While the first construction system can be produced with conventional machining technology in the timber industry, the second system was developed in conjunction with innovative robotic manufacturing methods. In order to evaluate the relationships and trade-offs of fabrication complexity and performance, the two systems are compared on a range of metrics, including material use, environmental impact and costs.
New possibilities offered by recent modelling software allow the design of organic shapes that are appealing to architects and engineers but may encompass serious issues such as an overconsumption of materials. In this context, there is a renewed interest in systems allowing the materialization of curved surfaces such as timber gridshells, which can be defined as shells with their structures concentrated in strips. However, gridshell design becomes highly challenging if complex grid configurations and new material possibilities are combinedly explored with form generations. These upheavals highlight the need for a classification system to seize the potential and the limitations of timber gridshells to address complex geometries. The classification of 60 timber gridshells enables a critical examination in the course of the ceaseless quest for complexity in architecture by evaluating current building possibilities and predict future building opportunities in terms of form, structure, and materiality.
This paper discusses the digital automation workflows and co-design methods that made possible the comprehensive robotic prefabrication of the BUGA Wood Pavilion—a large-scale production case study of robotic timber construction. Latest research in architectural robotics often focuses on the advancement of singular aspects of integrated digital fabrication and computational design techniques. Few researchers discuss how a multitude of different robotic processes can come together into seamless, collaborative robotic fabrication workflows and how a high level of interaction within larger teams of computational design and robotic fabrication experts can be achieved. It will be increasingly important to discuss suitable methods for the management of robotics and computational design in construction for the successful implementation of robotic fabrication systems in the context of the industry. We present here how a co-design approach enabled the organization of computational design decisions in reciprocal feedback with the fabrication planning, simulation and robotic code generation. We demonstrate how this approach can implement direct and curated reciprocal feedback between all planning domains—paving the way for fast-paced integrative project development. Furthermore, we discuss how the modularization of computational routines simplify the management and computational control of complex robotic construction efforts on a per-project basis and open the door for the flexible reutilization of developed digital technologies across projects and building systems.
The current study uses knowledge from digital architecture, computer science, engineering informatics, and structural engineering to formulate an algorithmic framework for integrated Computer-Aided Design (CAD) and Computer-Aided Engineering (CAE) of Integrally-Attached Timber Plate (IATP) structures. The algorithm is designed to take the CAD 3D geometry of an IATP structure as input and automates the construction and analysis of the corresponding CAE model using a macroscopic element, which is an alternative to continuum Finite Element (FE) models. Each component of the macro model is assigned a unique tag that is linked to the relevant geometric and structural parameters. The CAE model integrity is maintained through the use of the common data model (CDM) concept and object-oriented programming. The relevant algorithms are implemented in Rhinoceros 3D using RhinoCommon, a .NET software development kit. Once the CAE macro model is generated, it is introduced to the OpenSees computational platform for structural analysis. The algorithmic framework is demonstrated using two case structures: a prefabricated timber beam with standard geometry and a free-form timber plate arch. The results are verified with measurements from physical experiments and FE models, where the time needed to convert thousands of CAD assemblies to the corresponding CAE models for response simulation is considerably reduced.
Recent development in research and practice for curved cross-laminated timber (CLT) opens up novel and interesting possibilities for applications of slender surface-active shell structures in architecture. Such typologies provide advantageous structural behaviour allowing for efficient and lightweight structures while simultaneously determine the envelope and space of a building. The high degree of prefabrication combined with a sustainable and renewable building material makes CLT an ecological and economic solution for future construction. This paper presents the design development and construction of the Urbach Tower for the Remstal Gartenschau 2019: a structure made from high curvature CLT components on a building scale. This research contribution illustrates a sophisticated integrative design to construction process emphasizing computational and structural design, fabrication and detailing for curved timber components in complex spatial structures. The authors further explore the structural potential of self-shaped curved CLT investigating the influence of curvature radius on the load-bearing behaviour of the tower structure. The Urbach Tower translates these technical developments into practice arising at the intersection of digital innovation and scientific research.
The presented research describes the holistic development of a modular lightweight timber shell. So-called segmented timber shells approximate curved geometries with the use of planar plates, thus combining the excellent structural performance of double curved shells with the resource-efficient prefabrication of timber modules using only planar elements. Segmented timber shells constitute a novel building system that demands for innovative approaches on structural design and construction technologies. The geometric complexity of plate shells in conjunction with the particularities of the building material wood pose great challenges to the computational design and planning processes as structural requirements and fabrication constraints determine the shell design at early design phases. This paper discusses the design development and construction of the BUGA Wood Pavilion: A segmented timber shell structure made of hollow cassette components. Particular emphasis lies on the technical challenges of the employed building system, notably structural design and analysis, detailing solutions and the construction process. The authors further describe the integrative structural design and optimization methods developed for the timber shell in question. The BUGA Wood Pavilion demonstrates the possibilities of lightweight and sustainable wood architecture merging the merits of integrative design, structural engineering and high-tech robotic fabrication methods.