宋式古建筑木结构有限元模拟及承载特征

Finite element simulation and load-bearing characteristics of traditional wooden structures in Song style

为提出宋式古建筑木结构的有限元模拟方法并揭示其承载特征,分析了与础石接触的柱脚和与普拍枋接触的柱头的转动特性,并给出了柱脚和柱头恢复力矩的显示表达式.研究了考虑普拍枋影响的柱头燕尾榫节点恢复力矩解析模型.并建立了宋式古建筑木结构弹簧-梁单元有限元模型,研究了此类结构的承载特征.结果表明:建立的模型可以较好地表征木结构的承载能力,当木结构向右侧变形时,竖向荷载由普拍枋左侧传递给柱头,由普拍枋右侧传递给柱头和阑额,普拍枋与柱头之间的压力随加载位移的增大而减小,普拍枋与阑额之间的压力随加载位移的增大而增大.木柱和柱头燕尾榫节点提供的承载能力是三种竖向荷载作用下木结构侧向承载能力的主要组成部分.三种竖向荷载工况下,木柱提供的承载能力均大于60%,木柱的承载能力贡献比随竖向荷载的增大而增大.

In order to propose a finite element simulation method for the traditional wooden structure in Song style and reveal its load-bearing characteristics.The rotation characteristics of the column foot in contact with stone and the column head in contact with the Pupaifang are analyzed,and the analytical expressions of the restoring moments of the column foot and the column head are given.The analytical model of restoring moment of the dovetail mortise-tenon joint at column head considering the influence of the Pupaifang is studied.The finite element model of traditional wooden structure of Song style is established by spring and beam elements,and the load-bearing characteristics of wooden structure are studied.The results show that the finite element model can well simulate the bearing capacity of the wooden structure.When the timber structure deforms to the right side,the vertical load is transmitted from the left side of Pupaifang to the column head,and from the right side of Pupaifang to the column head and Lan′e.The compression force between the Pupaifang and column decreases with the increase of loading displacement,the compression force between the Pupaifang and the Lan′e increases with the increase of loading displacement.The resistance provided by wood column and dovetail mortise-tenon joint at column head is the main component of the lateral force of wood structure under three vertical loads.Under the three vertical load conditions,the resistance provided by the wooden column is greater than 60%,and the contribution ratio of the bearing capacity of the wooden column increases with the increase of the vertical load.