Quasi-static strengths and failure modes of tight-fitting and round-end metal-plate wooden truss joints

An experimental study was conducted to investigate whether existing industry design procedures for tight-fitting metal-plate-connector truss joints can be applied to the design of joints made with round-end webs. Four joint configurations were tested with a range of connector-plate sizes: 45° with web in tension, 45°-45° with one web in compression and the other in tension, 45°-90° with the 45° web in compression and the 90° web in tension, and 45° with the web under compression. In total 87 tight-fitting and 171 round-end joints were tested. As expected the tight-fitting joints were stronger and stiffer than round-end joints. Both the shear strength of the metal plate connector and the teeth pullout strength were smaller in the round-end joints than in the tight-fitting joints. Design guidelines are suggested for round-end joints.