Stretch-induced wrinkling of highly orthotropic thin films
Stretch-induced wrinkling of highly orthotropic thin films
复制标题
DOI：
10.1016/j.ijsolstr.2018.02.005
复制
发表时间：
2018-05
影响因子：
3.6
通讯作者：
Juner Zhu;Xiaowei Zhang;T. Wierzbicki
中科院分区：
文献类型：
--
作者：
Juner Zhu;Xiaowei Zhang;T. Wierzbicki
当矩形板在完全夹紧的边界下拉伸时，通常会观察到起皱。高正交各向异性聚丙烯薄膜的实验结果显示出一种违反直觉的现象——在低刚度方向拉伸时会出现皱纹，而在高刚度方向拉伸时则不会观察到皱纹。利用能量方法对该问题进行综合分析，将总能量分解为具有不同物理意义的几个分量。阐明了拉伸引起的起皱的机理，并发现，为了形成皱纹，横向上释放的能量必须超过加载方向上的弯曲、剪切、面外膨胀和拉伸的能量势垒。基于能量分析，建立了半解析模型，并通过引入正交各向异性系数（横向刚度与加载方向的刚度之比）扩展了各向同性材料临界拉伸应变的 Puntel-Deseri-Fried 解。发生起皱的下限标准是基于多种简化推导出来的。与实验结果相比，临界拉伸应变的扩展解和罕见准则都具有令人满意的精度。
Wrinkling is commonly observed when a rectangular plate is stretched with fully-clamped boundaries. Experimental results of a highly orthotropic polypropylene thin film show a counterintuitive phenomenon – wrinkles occur when stretched in the low-stiffness direction, while no wrinkles are observed when stretched in the high-stiffness direction. A comprehensive analysis of this problem is carried out using energy approach by decomposing the total energy into several components with different physical meanings. The mechanism of stretch-induced wrinkling is clarified and it is found that for the formation of wrinkles, the energy release in the transverse direction must exceed the energy barriers for bending, shearing, out-of-plane expanding, and stretching in the loading direction. Based on the energy analysis, a semi-analytical model is established and the Puntel–Deseri–Fried solution of critical stretch strain for isotropic materials is extended by introducing the coefficient of orthotropyr, which is the ratio of stiffness in the transverse direction to the loading direction. The criterion of the lower limit ofrfor wrinkling to occur is derived based on several simplifications. Both the extended solution of the critical stretch strain and the criterion ofrare shown to be of satisfactory accuracy, as compared to experimental results.