Caustics method in dynamic fracture problem of orthotropic materials
- 作者：Kezhuang Gong ; Zheng Li
- 关键词：ustics method ; Orthotropic composite ; Stress intensity factor ; Dynamic fracture
- 刊名：Optics and Lasers in Engineering
- 出版年：2008
- 期刊代码：98_01438166
- 类别：cp
- 出版时间：August 2008
- 卷：46
- 期：8
- 页码：614-619
- 文件大小：434 K
摘要
Caustics method is a powerful optical technique in fracture mechanics because of its high sensitivity to stress gradients. In this paper, it is applied to resolve dynamic fracture problems in orthotropic composites. Considering most orthotropic materials are opaque, reflective caustics method is derived here by combining the fundamental principle of caustics method with the mechanical properties of orthotropic materials. Meanwhile, corresponding experiments are carried out for typical glass fiber-reinforced composites, where mode I and mixed-mode fracture states are taken into account. By recording and analyzing shadow spot patterns during the crack propagation process carefully, crack onset time, dynamic fracture toughness and crack growth velocity of orthotropic composite are determined. These results will be useful to evaluate the dynamic fracture properties of composites and further to optimize their designs.