用局部坐标系转置和刚度等效分析膜结构褶皱的新方法

弹性膜在荷载作用下会出现双向受拉、单向受拉、松弛三种状态，由于膜材几乎不能承受压力，当单向受拉和松弛单元中出现压应力时，应进行褶皱处理。基于普遍性的要求，针对正交各向异性膜材，本文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，并运用有限元软件Strand7及其开发程序Strand7API进行了编程验证。最后，本文运用新方法对典型膜结构实例在竖向荷载作用下的受力情况进行了全过程的分析，通过分析发现新方法能正确的处理褶皱膜单元，并可以得到膜结构在褶皱单元出现后的真实的荷载响应。

New method to analyze the wrinkled membrane by adjusting local coordinate system and equivalent stiffness

Elastic membrane would be taut, wrinkle or slack under loaded. Taut is the only one workable state ,as membrane can not resist any compression stress, the wrinkled or slack membrane must be disposed. Based on the universal theory ,a new method which is via adjusting local coordinate system and the equivalent stiffness matrix is used to modify the orthotropic wrinkled membrane .Finally, FEM software Strand7 and its application program interface which is named Strand7API is used to analyze the full-time response of a typical membrane structure under the vertical load. From analyses results, it is found that wrinkled and slack membrane elements are properly disposed, and the load response is attained after the emergence of the compressive membrane elements.