Numerical analysis on the lateral resistance and reinforcement of bolted glulam post and beam structures with local cracks

The lateral resistance of bolted glulam timber frame structural system is highly influenced by the mechanical performance of the moment-resisting connections, while local cracks are commonly observed in the bolted glulam connections with the restraint of steel fasteners to wood shrinkage. In this paper, a three-dimensional finite element model was established in business software ANSYS to investigate the influence of cracks on the cyclic behavior of moment-resisting bolted glulam connections and the strengthening effect of friction dampers installed in pre-cracked connections. The numerical model was validated by comparison with full-scale experimental results. Furthermore, a nonlinear numerical model was developed for the glulam timber post and beam structures, and comprehensive analysis was conducted to explore the effect of the number and location of pre cracked connections and the application of friction dampers on the lateral performance of framed structures. It was found that with local cracks set in the moment-resisting connections, the lateral stiffness and capacity of the framed structures can be reduced by 27% and 30%, respectively. With the installation of friction dampers in pre-cracked connections, the lateral capacity and energy dissipation capacity of the reinforced frame can be up to 1.36 and 2.77 times that of initially perfect frame.