正交正放类网架结构分析的分解刚度法

把正交正放类网架结构简化为构造上正交异性的夹层板,采用考虑剪切变形的具有三个广义位移的平板弯曲理论进行分析。基于分解刚度思想对三类屋面网架(正放四角锥网架、两向正交正放网架和正放抽空四角锥网架)进行了静力分析和固有振动分析,对三类竖向承重网架墙体进行了稳定性分析,给出了简便实用的计算公式。通过与有限元法分析结果的对比,表明了本文提出的方法作为一种简化的计算方法,其精度是比较高的,绝大多数的误差都小于5%,可以应用于工程结构的初步设计。此外,与其他的简化计算方法相比它的精度比较高而且计算过程大大简化了。

Splitting rigidity method for analysis of orthogonal and ortho-laid double-layer space grids

In this paper orthogonal and ortho-laid double-layer space grids have been assumed as orthotropic sandwich plate,and are analyzed by the theory of plate with consideration of shear deformation and three generalized displacements. Static analysis of double-layer space grids under distributed loading,natural vibration analysis and stability analysis of three kinds of double-layer space grids have been studied with splitting rigidity method.The calculating formulas for internal forces,displacements,fundamental frequency and critical load of double-layer space grids have been given.The comparison with the results of finite element method shows that as a simplified method,the method presented in this paper is pretty accurate,whose error is less than 5 percent in general.It can be used in the preliminary design of engineering structure in case that the internal forces,displacements,fundamental frequency and critical load of double-layer space grids can be obtained rapidly.Furthermore,comparing with other simplified method its solution is more accurate and its process is more simplified.