木楔加固对松动透榫节点抗震性能的影响

为研究木楔加固对带缝隙透榫节点在反复荷载作用下受力性能的影响,制作了包括完好节点、松动节点及木楔加固节点的3组足尺透榫节点模型。通过试验室足尺试验对比分析了3组节点的变形特征和破坏特点,研究了节点的弯矩-转角滞回曲线、刚度变化特性、耗能和应力状态等受力特点。结果表明:完好和松动节点的破坏形式为变截面出现延伸至榫头根部的木材顺纹撕裂破坏。木楔加固节点的破坏特征为木楔挤压破坏;木楔加固后,节点的滑移现象和捏拢效应减弱;松动节点抵抗外荷载的能力和耗能能力等特性均显著降低,木楔加固后节点的各项性能明显提高,其弯矩较松动节点的弯矩提高约30%。

Effects of wedge strengthening on seismic performance of loose penetrated mortise-tenon joint

In order to study the effects of wedge on the seismic performance of loose joints, three full-scale penetrated mortise-tenon joint models are made, including a standard joint, a loose joint and a loose joint with wedge respectively. The deformation characteristics and failure characteristics of three joints were compared and analyzed through laboratory full-scale tests. Hysteresis curves, skeleton curve, stiffness degradation law, energy dissipation and ductility of three joints were analyzed by full scale quasi static test as well. Results show that the failure mode of standard and loose joint is wood fiber torn along the grain at variable cross-section.The failure mode of the joint with wedge is the extrusion failure of wedge.The slipping phenomenon and pinch effect of hysteresis curve decrease after adding the wedge. External load resistance capacity and energy dissipation capacity of loose joint are obviously lower than that of standard joint, and the above performances of joint have a rising trend after adding the wedge. The bending moment of the joint with wedge is about 30% higher than that of the loose joint.