【摘要】 榫卯节点是木构古建梁柱连接的典型形式,节点的受力性能对木构架整体稳定性有着重要影响。为保护古建筑,采用数值模拟方法,以抬梁式木构古建的两种典型榫卯节点形式—直榫和燕尾榫为例,研究了弯矩作用下榫卯节点的破坏形式及破坏特征。基于两种榫卯节点的典型构造特征,建立了受弯荷载作用下的有限元模型。通过在梁侧面施加逐步增大的位移荷载(共10mm)来研究两种节点的拉、压、剪应力分布特征及节点的弯矩-转角关系,获得了节点在不同加载值的相应内力峰值及转角刚度变化情况。结果表明:在弯矩荷载作用下,直榫的榫头容易产生拉、压、剪破坏,而卯口相对不易产生破坏;而燕尾榫榫头与卯口都容易产生拉、压剪破坏,且破坏程度比直榫严重;另一方面,燕尾榫节点的转动刚度要大于直榫,因而不易产生转动,一旦发生转动,其破坏的可能性要大于直榫节点。更多还原

【Abstract】 Tenon-mortise joint is a typical connection means between beam and column of Chinese ancient timber buildings. Bearing performances of tenon-mortise joints have an effect on the stability of the whole timber structure. In order to protect Chinese ancient buildings,numerical simulation is taken to study damage types of tenon-mortise joints of Chinese ancient wooden buildings under bending loads. Two typical tenon-mortise joints of post and lintel structure are selected for simulation: Straight joint and Yan-wei( dovetail) joint. Finite element models of two tenon-mortise joints are built by ANSYS program. By applying displacement load on side face of beam( 10 mm upward) step by step status of tensile stress,compression stress,shearing stress and moment-rotation angle relationship of the two joints are studied. Peak values of stresses above at each step of both joints are obtained. The results show that for Straight joint under bending loads damage types of its tenon include tensile strength failure,compression strength failure and shearing strength failure; however its mortise will not be damaged; for a Yan-wei joint both the tenon and mortise will be damaged for tensile strength failure,compression strength failure and shearing strength failure; on the other hand,rotation stiffness of Yan-wei joint is larger than that of Straight joint,which means the Yan-wei joint is hard to be rotated,and once it is rotated,it is more likely to be damaged.更多还原