Abstract
In recent years, laminated materials attracted attention because they are superior in ratio strength, ratio hardness and workability. They are used widely in areas of aerospace applications, for example. Therefore, it is important to evaluate the fracture characteristic of the laminated material. However, there are few reports concerning impact load on the fracture toughness of these laminated materials. In this research, the impact three-point bending test was used as the basis for measuring dynamic fracture. We made a video with a high-speed video camera, and calculated dynamic fracture toughness, K_<CD>, using the digital image correlation method. In addition, the experiments using the dynamic caustics method were conducted, and K_<CD> was calculated similarly. As a result, the K_<CD> for the digital image correlation method and the caustics method showed extremely good correlation. When the mixed-mode ratio was large, dynamic fracture toughness K_<CD> increased.
