Evaluation of crack propagation behavior of porous polymer membranes
Evaluation of crack propagation behavior of porous polymer membranes
复制标题
DOI：
10.1016/j.polymertesting.2021.107124
复制
发表时间：
2021-02
期刊：
影响因子：
5.1
通讯作者：
Yasuhisa Kodaira;Tatsuma Miura;Shoma Ito;Kanako Emori;A. Yonezu;H. Nagatsuka
中科院分区：
文献类型：
--
作者：
Yasuhisa Kodaira;Tatsuma Miura;Shoma Ito;Kanako Emori;A. Yonezu;H. Nagatsuka
为了确定裂纹扩展的判据，本研究从实验和数值两个方面研究了多孔聚合物膜的裂纹扩展行为。在膜中引入缺口作为初始裂纹(预裂纹)，并施加单轴载荷以产生稳定的裂纹扩展。在试验过程中，使用CCD摄像机和数字图像相关(DIC)方法观察了裂纹的扩展。用DIC方法对裂纹扩展初期裂纹尖端附近的应变进行了实验测量。我们发现，在裂纹扩展之前，就已经发生了大规模的屈服。在所有拉伸试验中都观察到稳定的裂纹扩展。同时，利用有限元方法建立了模拟多孔聚合物膜的均匀模型，研究了裂纹尖端附近的应力/应变分布。本研究采用Deshpande和Fleck提出的屈服准则。将计算的应变分布与实验结果进行了比较，发现两者的分布是相似的。由DIC方法和有限元计算得到的应变分布得到了一个J积分值，可以用来研究裂纹扩展的判据。无论初始裂纹长度如何，裂纹扩展开始时的J积分值在所有测试中都是恒定值。我们的结论是，我们成功地确定了多孔聚合物膜中裂纹扩展的判据。我们采用DIC实验和有限元计算的综合研究对于识别多孔聚合物膜的裂纹扩展行为和确定裂纹扩展的判据是有用的。
This study experimentally and numerically investigated the crack propagation behavior of porous polymer membranes in order to identify the criterion for crack propagation. A notch was introduced into the membrane as an initial crack (pre-crack), and a uniaxial loading was applied to produce stable crack propagation. During the test, crack propagation was observed using a CCD camera and the digital image correlation (DIC) method. The strain around the pre-crack tip at the onset of crack propagation was measured experimentally using the DIC method. We found that large-scale yielding developed before crack propagation. Stable crack propagation was observed for all tensile tests. In parallel, a homogeneous model that mimicked the porous polymer membrane was created using the finite element method (FEM) to investigate the stress/strain distribution around the crack tip. This study adopted the yield criterion proposed by Deshpande and Fleck. The computed strain distribution was compared with the experimental results, and the distributions were found to be similar. The strain distribution obtained by the DIC method and FEM computation yielded a J-integral value, which could be used to investigate the criterion for crack propagation. Regardless of the initial crack length, the J-integral value at the onset of crack propagation was a constant value for all tests. We concluded that we successfully determined the criterion for crack propagation in the porous polymer membrane. Our comprehensive study using DIC experiments and FEM computations is useful for identifying the crack propagation behavior of a porous polymer membrane and for determining the criterion for crack propagation.