In this paper, the mechanical performance improvement of traditional penetration mortise–tenon (PMT) connections reinforced by self-tapping screws (STSs) were experimental and numerical studied. Four unreinforced penetration mortise–tenon connections and four STS-reinforced connections were experimentally investigated under monotonic and low-frequency cyclic loading. Besides, the numerical model of PMT connections reinforced by STSs with different diameters and yield strength were established and analyzed.Their failure modes, rotational stiffness, moment-resisting capacity, ductility, and seismic behavior were studied. The experimental results indicated that the STSs reinforcements could enhance the moment-resisting capacity of the penetration mortise–tenon connection. Compared with unreinforced connections, the initial stiffness of STS-reinforced connections increased by 75% with the moment-resisting capacity increasing by 69%, respectively. Furthermore, the STSs reinforcement method can effectively restrict the pull-out of tenon during the whole loading process. Numerical simulation results showed that the yield strength of STS has little effect on the moment-bearing behavior of the connection. The diameter of STS significantly influences the connection performance, and the diameter of 8 mm is suggested.

To investigate the potential of modified epoxy resin for repairing and strengthening historical wooden structures, this study utilized polyurethane and silicone-modified epoxy resin as the base, alongside a polyamine curing agent. The resin mixture was cured at ambient temperature, resulting in the creation of ten unique epoxy resin systems. Investigation into the chemical structure and alterations to the glass transition temperature were conducted. The study conducted tests and characterization of viscosity, curing rate, mechanical properties, stress failure mode, hygrothermal aging resistance, and bonding properties. The results reveal that the curing degree of the two modified epoxy resins is high after being cured at room temperature, and the chemical structure and curing rate show insignificant changes. The range of the glass transition temperature for the modified epoxy resin is between 61.31 °C and 70.51 °C. The incorporation of polyurethane and silicone molecular chains into the epoxy resin cross-linking curing system enhances the toughness of the epoxy resin. The modified resin achieves a maximum elongation at break that is 5.18 times greater than that of the unmodified resin, along with a maximum tensile strength and a compressive strength that are 7.94 and 1.74 times, respectively, higher than those in the Chinese technical specifications for the maintenance and reinforcement of ancient wooden structures. The increase in toughness changes the failure mode of the cured epoxy resin. The modified epoxy resin exhibits great bonding ability to aged wood, with a shear strength of up to 9.6 MPa along the grain. As a result, the modified epoxy resin meets the requirements for the reinforcement and repair of the timber members of ancient buildings.

Walking-induced vibration control in wood floors is a critical issue attracting the attention of many researchers and engineers. This paper presents an experimental study applying static deflection tests, modal tests, and pedestrian load tests to a series of full-scale 12 m span tooth plates connected to wood truss joist floors with strongbacks and partition walls. A comparison of the calculation error of vibration parameters between the theoretical formula and a numerical model was also conducted. The results show that strongbacks and partition walls effectively reduce both the vertical displacement and the root means acceleration at the center of the floor under pedestrian load but increases the natural frequency. The partition wall can achieve a better vibration-reduction effect than strongbacks. The error of the finite element model is higher than that of the theoretical formula. Using the theoretical formula in engineering wood floor design is recommended.