广府木祠堂箍头榫节点力学性能试验研究

Experimental Investigation into Mechanical Behaviors of Hoop Head Tenon Joint of Timber Ancestral Hall in Canton

以岭南地区具有代表性的广府木祠堂建筑为研究对象,分别进行了1榀菠萝格木构架缩尺模型的竖向加载与1榀木构架缩尺模型的水平低周反复加载试验,研究广府木祠堂箍头榫节点的力学性能.通过木构架的竖向荷载试验,获取箍头榫节点在竖向荷载作用下的破坏形式、受力特点和刚度特性;从木构架的水平低周反复荷载试验中,得到箍头榫节点在水平荷载作用下的破坏形式、滞回曲线、骨架曲线、延性、刚度退化及能量耗散能力等性能.试验结果表明,木构架在梁跨中竖向荷载作用下为梁底部木纤维突然拉断而破坏;而木构架在水平低周反复荷载作用下为节点梁端外侧被挤压劈裂破坏,箍头榫节点呈现出典型的半刚性,其滞回曲线较为饱满,割线刚度曲线呈下凹型且趋于收敛,等效粘滞阻尼系数较大,试件表现出较好的抗震性能.

The typical timber ancestral halls in Canton in Lingnan area were investigated in this paper. In order to explore the mechanical properties of the hoop head tenon joints of the timber ancestral hall, one scaled model of Merbau timber frame was tested under the vertical static load while one scaled model of timber frame was tested un- der the low-cycle reversed loading. By the former test, the behaviors of the hoop head tenon joints, such as the failure mode, the mechanical characteristics and the stiffness characteristic, were obtained. By the latter test, the behaviors of the hoop head tenon joints, such as the failure mode, the hysteretic curves, the skeleton curves, the ductility, the stiffness degradation and the energy dissipation, were gained. Experimental results show that the specimen under the vertical static load fails because the bottom wood fiber of the beam breaks, while the specimen under the low low-cycleic reversed loading fails because of the splitting failure of the lateral of the beam end. In addition, under the low low-cycleic reversed loading, the hoop head tenon joints show a semi-rigid characteristic with a plump hysteretic curve, a concave and convergent stiffness curve, and a large equivalent viscous damping coefficient, which means that the specimen has a good seismic behavior.