Prediction of the load carrying capacity of bolted timber joints

Failure of bolted timber joints is analyzed experimentally and numerically. In this study, the prediction of the load-carrying capacity of dowel-type joints with one dowel under static loading is based on the analysis of frac ture in wood contrarily to most engineering methods that are based on the y ield theory. Mechanical joints consist of glued laminated spruce members an d steel dowels. In the different analyzed tests, the bolt loads the wood pa rallel or perpendicular to the grain. The wood member thickness is chosen s ufficiently thin to avoid the fastener from presenting plastic hinges. The influences of different structural parameters such as the dowel diameter, t he edge- and end-distances are investigated. The fracture propagation analy sis is carried out with the Finite Element (FE) method in the framework of Linear Elastic Fracture Mechanics (LEFM). The only identified parameter is the critical energy release rate in mode I (G(IC)). The comparison between experimental and numerical results shows that the fracture must be consider ed for a correct prediction of the ultimate load and that LEFM can help to improve design codes.