网格式框架的等效抗侧刚度分析

Analysis of Equivalent Lateral Resisting Stiffness for Grid Frame Structure

为了解网格式框架抵抗水平荷载作用的能力,基于D值法,假定轴力在结构横截面上呈线性分布,且考虑弯曲变形和剪切变形的影响,得到了在倒三角形分布荷载、均布荷载和顶点集中荷载等作用下结构的等效抗侧刚度公式,并用有限元法及试验做了对比.结果表明:结构侧移以剪切变形为主,但弯曲侧移的影响随结构高度的增加而增加,因此应考虑弯曲侧移对总侧移的影响;中柱的轴向变形对结构抗侧刚度及侧移的影响较小;与有限元法及试验结果的折算抗侧刚度相比,本文的等效抗侧刚度公式具有理想的计算精度,可用于预估结构的抗侧能力.

In order to understand the resistance of grid frame structure under horizontal loads,based on D-value method,assuming that axial force is linearly distributed on structural cross section and considering the influence of bending and shear deformation,this study deduced the equivalent lateral resisting stiffness formula under inverted triangular load,uniformly distributed load and vertex concentrated load.The results were compared with that of finite element method and experiment.The results show that lateral displacement of this structure is given priority to shear deformation,and with the increase of structure height,the influence of bending displacement becomes larger,so that the effect of bending displacement on the total lateral displacement should be considered.The influence of axial deformation of middle column on structural lateral resisting stiffness and displacement is smaller.Compared with the calculated lateral stiffness by finite element method or test results,the equivalent lateral stiffness formula in this paper has reliable calculation accuracy,and can be used to estimate the capability of resisting lateral deformation.