由于膜材不能抗压,在薄膜结构受力分析中膜材有纯拉、单向褶皱和双向褶皱3种状态.当膜材处于褶皱状态时,其受力性能与纯拉状态有很大的差异,在分析中应予以区别,故对膜材3种受力状态的界定成为必要.本文对目前常用的判别柔性材料受力状态的3种准则进行了详细论述,分别讨论了各自的原理及存在的问题,得出主应变准则只能适用于各向同性膜材,主应力主应变准则对各向同性和正交异性膜材均能适用.并给出了膜材产生褶皱后的处理方法.
As membrane cannot resist any compression stresses, there are three possible states: taut, wrinkled, and slack when membrane structures been loading. There are many differences between taut behavior and wrinkling behavior of the structure. Therefore it is important to develop effective analysis methods for the evaluation of the taut, wrinkle and slack. Three criteria are discussed. It is shown that principal strain criterion is only suitable for the isotropic membranes and principal stress-principal strain criterion is suitable for both the isotropic and orthotropic membranes. Also, a method for the wrinkling analysis of orthotropic and isotropic membranes was presented.