【摘要】 残损是现存古建筑木结构的普遍状况,显著地降低了结构的抗震性能。为研究残损对燕尾榫节点抗震性能的影响,参照宋《营造法式》殿堂三等材的尺寸要求,制作了3个比例为1∶3.2的燕尾榫节点模型,包括1个完好节点、1个模拟榫头真菌腐朽的残损节点和1个模拟榫头虫蛀的残损节点。榫头真菌腐朽和榫头虫蛀分别采用在榫头表面钻一定深度的孔和在榫头钻通孔的方法来模拟。通过低周反复加载试验对残损节点的破坏特征、弯矩-转角滞回曲线、骨架曲线和耗能性能进行了研究,分析了残损燕尾榫节点抗震性能的退化规律。结果表明:残损燕尾榫节点的破坏形态与完好节点的破坏形态类似,主要表现为榫头和卯口有明显的挤压变形、榫头沿枋纵向部分拔出,枋柱整体完好,但残损节点的榫头拔出更早、拔出量更大,模拟虫蛀节点有榫角被挤碎;残损燕尾榫节点的滞回曲线也有明显的"捏缩"效应,但滞回环饱满度较差;残损节点的转动弯矩、转动刚度均明显低于完好节点,但耗能能力基本不变化;当两种不同残损类型的残损程度相近时,人工模拟真菌腐朽节点的转动弯矩更高、转动刚度更大。更多还原

【Abstract】 Damage is a common state for existing ancient wood structures,it reduces their aseismic performance dramatically. In order to investigate the influence of damage on the aseismic performance of dovetail mortise-tenon joints,3 mortise-tenon joints with a 1 ∶ 3. 2 scale including 1 intact joint,1 joint artificially degraded by fungi and 1 joint artificially degraded by termites were made according to the fabrication methods of Song dynasty. Several holes with a certain depth were drilled uniformly on the entire surface of the tenon to simulate fungi damage,while several holes were drilled through cross section on the entire tenon to simulate the damage by termites. The aseismic behaviors,such as,failure characteristics,hysteretic curve,skeleton curve,degeneration of stiffness and energy dissipation,were studied comparatively with low-cyclic reversal loading tests. The results showed that the failure patterns of damaged joints are similar to those of the intact joint,they are mainly squeeze deformation of mortise and tenon,and partial evulsion of the tenon,the beams and columns are intact; moreover,for the damaged joints,the evulsion of the tenon is earlier and bigger,and some tenons of the man-made termites damage joint are crushed partly in the corner; the hysteretic curves of damaged joints have obvious "gathering effect",but the curves are not very full; the bending- bearing capacity,and stiffness of damaged joints are significantly less than those of the intact one,while their energy dissipation ability has no change basically; when damage levels are similar,the final bending- bearing capacity and stiffness of the man-made fungi damage joint are bigger than those of the man-made termites damage joints,but their energy dissipation capacity is almost the same.更多还原