褶皱膜的局部坐标系转置和刚度等效法分析

Method to Analyze Wrinkled Membranes by Using Local Coordinate Transpose and Equivalent Stiffness

在对膜结构进行荷载分析时,单向受拉和松弛的膜单元会出现不符合实际受力情况的压应力,计算过程中应对它们进行褶皱处理.为此,文中提出了采用局部坐标系转置和刚度等效分析褶皱膜单元的新方法,并采用有限元软件Strand7及其开发程序Strand7API编制了相应的程序,最后用所编制的褶皱分析程序对典型膜结构在竖向荷载作用下的受力情况进行了全过程的实例分析.通过分析发现新方法经迭代计算可使褶皱单元的第二主应力基本为0,正确地处理了褶皱膜单元,并得到了膜结构在褶皱单元出现后的真实的荷载响应.

In the load analysis of membrane structures,incorrect compressive stresses exist in one-way wrinkled and slack membranes,so that wrinkling analyses should be performed in the calculation process of the structures.This paper proposes a new method to analyze wrinkled membranes by using the local coordinate transpose and the equivalent stiffness,and presents the corresponding program based on the finite element software Strand7 and its application program interface Strand7API.The program is then used to analyze the whole-process response of a typical membrane structure under vertical loads. The results indicate that, after the iterative calculation, the proposed method makes the second principal stress basically be zero, correctly deals with wrinkled membranes, and helps to obtain the actual load responses of membranes after the emergence of wrinkles.