张拉膜结构的有限元分析

应用有限元程序ANSYS进行了薄膜结构的找形分析和荷载分析．张拉结构受力后将产生较大的位移，因此需要采用非线性理论．通过一系列计算，可以发现影响找形结果的因素有：单元的划分，初始弹性模量的选取，膜的预张力，边索和脊索的预张拉力值及其比值．在实际工程中，由于膜结构建筑要求和边界条件的限制，找到具有极小曲面性质的初始平衡形状较难，因此，一般把应力的差值控制在一定的范围内．工程实例计算结果表明：在风荷载作用下膜结构的竖向位移反应比较大，风吸力通常是索膜结构设计的控制因素．

THEORETICAL ANALYSES OF TENSION MEMBRANE STRUCTURES

This paper presents a theoretical investigation for the form finding and the loading analyses of membrane structures by using the finite element package ANSYS. The tension structures under loading usually involve large displacements, so the non-linear theory is applied in theinvestigation. It is found that the results of form finding depend on the following factors: the meshing, the elastic moduli of the membrane material, the initial stress in the membrane, the stress in the boundary cables and the ridge cables and their ratio. In practical engineering, it is difficult to find out the minimal surface meeting the architecture demands and the boundary restrictions, hence, the difference in the stress distribution should be controlled in a special range. The computational results for practical examples show that the effect of the wind loading on the vertical displacement is significant. Usually the design of membrane structures is controlled by the wind suction.