Static and Dynamic Stress Intensity Factors by the Method of Transmitted Caustics

The stress intensity factors in plexiglas plates containing an edge crack and subjected to static or dynamic loading are determined by the optical method of caustics. Measurements of the applied load were accomplished by means of a piezoelectric transducer and the caustics obtained in the experiments were photographed during the process of loading by using a Cranz-Schardin high speed camera. It has been found that the stress intensity factors for a dynamic loading are always higher than the corresponding stress intensity factors for a static loading of the same magnitude.