The three-dimensional mechanics and failure of single bolt wood connections

The interaction of connection end distance and aspect ratio for a simplified version of a bolted wood connection was evaluated experimentally and was modeled numerically through application of a three-dimensional finite element analysis. Douglas-fir was the wood species considered. Connection aspect ratios ranged from ;The experiments provided measurements of load vs displacement behavior and connection failure modes. Numerical model predictions also included load vs. displacement behavior and predicted failure modes, both of which were compared with the experimental results. Noncatastrophic failure modes included combined wood crushing and pin yielding, while catastrophic failure modes included wood fracture with and without pin yielding.;The numerical model successfully predicted the end distance ratio (e/d) and aspect ratio (;A decrease in stiffness was seen in connections with e/d less than 4. Increasing the end distance beyond e/d = 4 in connections with ;The finite element model included effects of clearance between the pin and the hole, plasticity in the steel pin, nonlinear orthotropic material constitutive behavior in the wood, and changing contact region between the pin and the hole as the connection was loaded.;The yield stress of the steel pin had a significant effect on the predicted behavior of connections with larger aspect ratios. In contrast, the numerical predictions were insensitive to minor changes in the nonlinear wood constitutive model. Results show that it is necessary to use nonlinear constitutive behavior for the wood and steel in order to adequately predict connection load vs. displacement behavior.