Prefabricated Structural Timber Elements using wood-wood connections


Funding: NCCR Digital Fabrication

Status: Ongoing since 2016

PhD Student: Julien Gamerro, engineer, IBOIS

Thesis director: Prof. Yves Weinand, architect and engineer, IBOIS

Co-supervisor: Jean-François Bocquet, senior lecturer, ENSTIB


Steel fasteners and adhesive bonding are generally used as connections for modern timber structures replacing traditional wood-wood assemblies. Nevertheless, the emergence of digital fabrication in timber construction has opened new design possibilities for wood-wood connections especially for timber plate structures. The increasing interest from industry and research on this topic have led to real buildings, such as the Vidy theater in Lausanne, showing the feasibility of these construction techniques. However, the research has tended to focus on specific geometries like origami and free-form rather than on standard structural elements as presented by L. Sass with the wood grammar frame. As a result, the mechanical behavior of these particular wood-wood connections has been investigated mostly on rotation for the application on folded surface structures.

Therefore, the purpose of this research is to present the development and mechanical behavior of standard structural elements using Oriented Strand Board (OSB) and Laminated Veneer Lumber (LVL) panels for slab or roof components using wood-wood connections. The objectives are to introduce a simplified calculation method based on beam elements and to compare its accuracy with an experimental investigation on large samples in order to satisfy the current standards for timber engineering. An implementation at building scale is planned with a partnership company.

Figure 1- (a) Axonometry of the prefabricated element (b) Photo of the prefabricated element under fabrication (c) Robotic line equipped with special tool for timber panels [credit photo: Cedric Moutschen, MOBIC SA]

Figure 2- Laboratory tests

This research was supported by the NCCR Digital Fabrication, funded by the Swiss National Science Foundation. (NCCR Digital Fabrication Agreement # 51NF40-141853)
Link to publications