A Collaborative Workflow to Automate the Design, Analysis, and Construction of Integrally-Attached Timber Plate Structures

This paper introduces a computational framework that fosters collaboration between architects, engineers, and contractors by bridging the gap between architectural design, structural analysis, and digital construction. The present research is oriented toward the formulation of an automatic design-to-construction pipeline for Integrally-Attached Timber Plate Structures (IATPS). This construction system is based on assembling timber panels through the sole interlocking of wood-wood connections inspired by traditional Japanese joinery. Prior research focused on developing distinct computational workflows and dealt with the automation of 3D modelling, numerical simulation, fabrication, and assembly separately. In the current study, a single and interactive design tool is presented. Its versatility is demonstrated through two case studies, as well as the assembly of a physical prototype with a robotic arm. Results indicate that efficiency in terms of data flow and stakeholder synergy is considerably increased. The proposed approach contributes to the†Sustainable Development Goal (SDG) 11 by facilitating the collaborative design of sustainable timber structures. Besides, the research also contributes to SDG 9 as it paves the way for sustainable industrialisation of the timber construction sector through streamlined digital fabrication and robotic assembly processes. This reduces manufacturing time and associated costs while leveraging richer design possibilities.

Integrally-Attached Timber Plate Structures: From computational design to robotic construction

Nicolas Henry P Rogeau

This poster provides an overview of the challenges and achievements related to current research led at the Laboratory for Timber Constructions (IBOIS, EPFL) on the robotic assembly of Integrally-Attached Timber Plate Structures (IATPS). The poster is divided into two columns corresponding to the two main parts of the research. On the left, the “Computational Design” part summarizes the key points of the development of Manis – a collaborative design tool for IATPS that integrates fabrication and assembly constraints as well as feedback on the structural performance. On the right, the “Robotic construction” part addresses the experiments carried out to determine an optimal shape for timber joints so that they can be inserted with a robotic arm with a minimum of tolerance. Ultimately, the research aims to provide a fully automated workflow from design to construction in order to foster the adoption of this all-wood construction system by AEC stakeholders.

2022

Building timber structures with robots!

Nicolas Henry P Rogeau

In recent years, the necessity of using renewable and sustainable resources in the construction sector has become obvious. This has led to a revived interest in the natural advantages of timber as a building material. To this end, the Laboratory for Timber Constructions (IBOIS) aims to develop more efficient design and construction methods using digital tools such as robots, CNC machines, scanners, and augmented reality. Current research focuses on the development of so-called Integrally-Attached Timber Plate Structures (IATPS). This innovative construction system is inspired by ancient Japanese carpentry techniques. It uses interlocking joints to connect timber panels and create outstanding spatial structures (see below). Using timber connections provides a more sustainable alternative to standard gluing and screwing processes. The joints also help to guide the pieces during the assembly transforming the construction in a kind of large-scale puzzle. Another advantage of IATPS is the possibility to prefabricate all the pieces with the help of state-of-the art digital tools such as CNC routers and robots. To facilitate the adoption of IATPS in the industrial world, IBOIS researchers have developed a virtual design interface that helps architects, engineers and contractors to automate the creation of timber joints between the panels, compute associated structural analysis, as well as generate fabrication toolpaths and robotic trajectories.

2022

Development of Novel Standardized Structural Timber Elements Using Wood-Wood Connections

Julien Gamerro

Traditional wood-wood connections, widely used in the past, have been progressively replaced by steel fasteners and bonding processes in modern timber constructions. However, the emergence of digital fabrication and innovative engineered timber products have offered new design possibilities for wood-wood connections. The design-to-production workflow has evolved considerably over the last few decades, such that a large number of connections with various geometries can now be easily produced. These connections have become a cost-competitive alternative for the edgewise connection of thin timber panels. Several challenges remain in order to broaden the use of this specific joining technique into common timber construction practice: (1) prove the applicability at the building scale, (2) propose a standardized construction system, (3) develop a convenient calculation model for practice, and (4) investigate the mechanical behavior of wood-wood connections. The first building implementation of digitally produced through-tenon connections for a folded-plate structure is presented in this work. Specific computational tools for the design and manufacture of more than 300 different plates were efficiently applied in a multi-stakeholder project environment. Cross-laminated timber panels were investigated for the first time, and the potential of such connections was demonstrated for different engineered timber products. Moreover, this work demonstrated the feasibility of this construction system at the building scale. For a more resilient and locally distributed construction process, a standardized system using through-tenon connections and commonly available small panels was developed to reconstitute basic housing components. Based on a case-study with industry partners, the fabrication and assembly processes were validated with prototypes made of oriented strand board. Their structural performance was investigated by means of a numerical model and a comparison with glued and nailed assemblies. The results showed that through-tenon connections are a viable alternative to commonly used mechanical fasteners. So far, the structural analysis of such construction systems has been mainly achieved with complex finite element models, not in line with the simplicity of basic housing elements. A convenient calculation model for practice, which can capture the semi-rigid behavior of the connections and predict the effective bending stiffness, was thus introduced and subjected to large-scale bending tests. The proposed model was in good agreement with the experimental results, highlighting the importance of the connection behavior. The in-plane behavior of through-tenon connections for several timber panel materials was characterized through an experimental campaign to determine the load-carrying capacity and slip modulus required for calculation models. Based on the test results, existing guidelines were evaluated to safely apply these connections in structural elements while a finite element model was developed to approximate their performance. This work constitutes a firm basis for the optimization of design guidelines and the creation of an extensive database on digitally produced wood-wood connections. Finally, this thesis provides a convenient design framework for the newly developed standardized timber construction system and a solid foundation for research into digitally produced wood-wood connections.

EPFL2020

Development of Novel Standardized Structural Timber Elements Using Wood-Wood Connections

Julien Gamerro

EPFL2020