木构古建梁柱节点拔榫过程数值仿真

榫卯节点是中国古建筑木结构梁柱连接的主要形式。为有效保护中国古建筑,文章采用数值模拟方法,以两种典型的榫卯节点——直榫和燕尾榫为研究对象,研究了榫头从卯口拔出过程中节点的内力和变形特性。基于两种榫卯节点的构造特征,建立了有限元分析模型,对比分析了拔榫过程中两种节点的位移、摩擦应力和等效应力等特征。结果表明:直榫在拔拉过程中变形和应力较小,不易破坏,但容易产生拔榫现象;而燕尾榫虽然不易拔榫,一旦在荷载作用下进行拔拉,则会在拔拉过程中因挤压变形和强度不足而产生破坏。

Process of tenon pulled out of mortise of chinese ancient beam-column joints by simulation

Tenon-mortise joint is a main connection means of beams and columns of Chinese ancient wooden buildings. To effectively protect Chinese ancient wooden buildings,2 typical types of tenon-mortise joint：straight joint and Yan-wei （ dovetail ） joint were taken as examples to study their mechanical characteristics during the process of tenon pulled out of mortise. Finite element analysis models of the 2 joints were built based on their constitutions. Then displacement load was applied to each tenon to make it pulled out of mortise. Distributions of displacement, friction force and equivalent stress of the 2 joints during pull course were compared. Results show that when the straight tenon is pulled out of mortise,its displacement and stress values are small,which makes it hardly to be destroyed. For the dovetail joint,its tenon can hardly be pulled out of mortise. However,once the tenon is pulled out under loads,it will be destroyed due to over large deformation as well as stress values during the course of pull.