Seismic behavior and theoretical analysis of mortise-tenon joints reinforced with steel components

Wood structures have been vigorously popularized and developed because they have low carbon emissions and acceptable earthquake resistance. To solve the general pull-out failure of mortise-tenon joints (MTJs) under earthquake loads, reinforcement techniques, such as steel strip plate (SSP), hollow rectangular steel plate (HRSP), U-shape steel plate (USP), and T-shape steel plate (TSP) methods, have been proposed. Low cyclic loading tests were conducted on five joints to investigate the effect of reinforcement methods on the seismic behavior of MTJs. Furthermore, the peak bearing capacity of reinforced MTJs was theoretically analyzed based on European, American, and Chinese specifications; the calculations were compared with the test results. To verify the accuracy of the theoretical analysis, ABAQUS software, a finite element simulation application, was used. The test results show that the failure modes of joints with or without reinforcements are tenon pull-out, self-tapping screw pull-out, and shear failure. Moreover, the USP-reinforced MTJ exhibited the best seismic performance, followed by the MTJs reinforced with TSP, HRSP, and SSP. The theoretical calculation and test results are in good agreement. The simulation results indicate that the proposed calculation methods can accurately predict the peak bearing capacity of steel-reinforced MTJs.