Numerical simulation of framed joints in sawn-timber roof trusses

Abstract

This paper presents an analysis of carpentry joints between structural timber members based on numerical simulation. In conventional design, simplifying assumptions of the stress distribution and the transmission of forces on the contacting surfaces are made, and the effect of contact friction between surfaces is neglected. Whereas a number of authors have been concerned with other types of joints, such as mechanical or glued joints between timber members, carpentry joints have hardly been subject to numerical simulations. This study presents a more realistic approach to the behaviour of these joints, using the finite element method, which enables further knowledge of the stresses acting on the joint. In addition, the finite element method enables the optimization of the geometric definition of carpentry joints between structural timber members. The numerical simulations performed for framed joints have revealed that friction between contacting surfaces has particular relevance for the behaviour of the joint. The Spanish Technical Building Code, among others, is based on conventional design. Numerical simulations have revealed a high level of safety in such a conventional definition of framed joints.