Dynamic fracture mechanics approach on damage tolerant design of the laminated materials using digital image correlation method

In recent years, the laminated materials are designed and used widely in aerospace applications, for example. Therefore, it is important to evaluate the fracture characteristic of the laminated materials. In this research, the basic study on damage tolerant design for the laminated materials subjected to impact load is systematized. The dynamic fracture behavior is analyzed by using the high-speed video camera and the digital image correlation method or caustics method. The dynamic stress intensity factor is experimentally calculated with both the digital image correlation method and caustics method. These two kinds of analysis results are compared, and the reliability of the analytical method in the digital image correlation method is confirmed. In addition, the mixed-mode ratio, dynamic fracture toughness and kinking angle are evaluated from the dynamic stress intensity factor for the control and forecast of fracture. And, the characteristic of mixed-mode fracture criterion showing the condition and the behavior of fracture is examined. It is shown to be able to properly act as damage tolerant design by the materials evaluation method. © 2010 The Society of Materials Science,.