Research on Mechanical Properties of a New Type of Glued Laminated Timber Splice Joints Connected with Prestressed Steel Strip and Self-Tapping Screw

A new type of laminated timber joint connected with prestressed steel strips and self-tapping screws is proposed to address the problem of bending and splitting of half-lapped beams in the laminated wood joint. An experimental study on the bending resistance of the joint under axial compression load was conducted, and the crack propagation and failure modes of the specimen were obtained. The mechanical properties of the new type of joints were analyzed based on the bending moment-deflection curve. The test results showed that the failure modes of the joint were mainly the pull-out failure of the horizontally oblique self-tapping screw, and the cracks at the shoulder angle were significantly restricted. The bearing capacity of the new type of joints was 72.5% of that of the intact laminated timber beams, compared to the glued laminated timber joint beams without horizontal inclined self-tapping screws, their bending load-bearing capacity has increased by 11.3%. To address the problem of complex and inefficient computation of the solid model of the self-tapping screw, a combination of solid and simplified models was proposed in the paper. The model's validity was verified based on the test results, and a fully simplified modeling method was proposed to further improve the calculation efficiency.