Strength Prediction for Rounded Dovetail Connections Considering Size Effects

Abstract

The strength prediction of rounded dovetail connections (RDCs), a relatively new connection for structural timber members, is difficult due to the anisotropic and brittle nature of the material, the complex stress distribution as well as the uncertainties regarding the associated material resistance. Experimental investigations were carried out to provide input and benchmark data for developing a method to predict RDC strength. Numerical analyses confirmed that the experimentally observed failure location was also the highest stressed part of the model. A probabilistic method is presented to predict the strength of RDC. The method, rather than being stress-based, incorporates size effect for the combined action of tension perpendicular to grain and shear parallel to grain stresses in timber by comparing computed stress volume integrals to unit volume strength thresholds. Therefore not only the magnitude of the stress distributions is considered but also the volume over which they act. The capacities of RDC configurations were predicted and successfully validated with experimental tests. The presented strength prediction method has immediate application for the improvement of RDC design.