网架结构拟夹层板法的有限元验证

用拟夹层板法和有限元法对网架结构进行分析，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）进行了均布荷载、局部荷载（半跨均布荷载）作用下的静力分析以及固有振动分析，对三类竖向承重网架墙体进行了稳定性分析。通过与有限元法分析结果的对比，表明了拟夹层板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％，是可以直接用于工程结构设计的一种有效方法。此外，拟夹层板法还可作为一种在宏观上检验有限元建模正确与否的实用方法。

The validation of equivalent sandwich plate method for double-layer space grids by Finite Element Method

Equivalent sandwich plate method (ESPM) is a method for the design of double-layer space grids. By this method the orthogonal and ortho-laid space grids is assumed as orthotropic sandwich plate, and is analyzed by the theory of plate with consideration of shear deformation and three generalized displacements. It has been used more and more widely in practical engineering. But the accuracy of ESPM when used in stability analysis, natural vibration analysis, etc., needs further systematic validation by Finite Element Method (FEM). In this paper double-layer space grids are analyzed by both equivalent sandwich plate method and finite element method. The static analysis of double-layer space grids under distributed loading and local loading, the natural vibration analysis and the stability analysis of three kinds of double-layer space grids have been studied. The comparison with the analysis results of finite element method shows that as a simplified method, equivalent sandwich plate method is very accurate, whose error is less than 5 percent in general. It also indicates that equivalent sandwich plate method can be used in the design of engineering structure because of that the accuracy of equivalent sandwich plate method can be sufficient. Furthermore, it also can be used to check the model of finite element method in general.