平面框架构件轴向约束刚度研究

Research on axial restraint stiffness of members in plane frame structures

以一典型4跨6层纯框架为例,用有限元方法计算了该框架结构所有构件的轴向约束刚度,并且对其影响因素进行了分析:目标梁或柱构件轴向约束刚度分别主要受其所在层或所在跨的子框架构件的影响。基于以上分析,推导出了平面框架构件轴向约束刚度的近似计算方法:为目标构件选取合适的子框架,然后计算出子框架中每一根构件贡献的侧移刚度和轴向刚度,最后按照刚度的串并联法则组合计算得到目标构件的轴向约束刚度。此近似方法可以较简便而相对准确地计算出框架构件的轴向约束刚度。

This paper first calculated the axial restraint stiffness of every member in a typical 4 bay and 6 story frame structure using finite element method.It is found that the target beam or column frame member＇s axial restraint stiffness is mainly influenced by the sub-frame on the same story or same bay respectively.Based on the analysis,an approximate solution was derived to calculate the stiffness： selecting appropriate sub-frame,calculating the contribution of each member in the sub-frame,and combining these contributions to obtain the axial restraint stiffness of the target member.This method provides a simple and relatively accurate approach to calculate plane frame member＇s axial restraint stiffness.