Bois lamellé-agrafé : détermination d’une formule du Kser appliquée aux connecteurs métalliques

Details

Supervisors

Latteur, Pierre

Faculty

Ecole polytechnique de Louvain

Degree label

Master [120] : ingénieur civil des constructions, à finalité spécialisée

Abstract

enIs it possible to manufacture large cross-section timber elements easily ? The answers to this question generally refer to glued laminated timber, whose manufacturing conditions are not so easy. This document attempts to answer this question in another way by considering a mechanical assembly element used for more than half a century. This is none other than the punched metal plate that could, like the glue present in glued laminated timber, hold together several superimposed wood strips. Although they are widely used, these metal fasteners are still complex to characterise, particularly their rigidity. Represented by a slip modulus Kser, there is no way of calculating it analytically as is the case for other types of connections. A theoretical study will be carried out in order to understand the ins and outs of the surface factener before launching a series of test campaigns. The latter will aim to determine the link between the slip modulus Kser of the connection and the density of the connected wood. Finally, a last experimental study will be carried out on beams assembled with metal facterners, laminated wood beams. An analysis will follow based on all the theoretical knowledge brought to light in this work. In particular, the numerical models constructed for the study of these beams such as the Gamma method, described in appendix B of the Eurocode 5. But also a numerical model made with the software SCIA or the programme dedicated to roof portal calculations, created by the world leader in punched metal plates. A first study on the subject having already been carried out by Corto Lahaye in 2020, this second work made it possible to give a good part of the relationship linking the slip modulus to the density of the wood. However, there are still parameters identified, but not studied, that have an influence on the stiffness of these connections. These mainly concern the geometry of the fastener itself and could be the subject of a series of further studies. In the study of laminated timber, the solution proposed in this thesis gave better results than the previous solution. The deformations are in the order of twice those that would be obtained with a glulam counterpart beam. This is not yet convincing but other ideas are proposed.