Measurement of Stress Intensity Factor for Orthotropic CFRP Laminate Material by Caustics Method

Abstract

The optical method of caustics is a useful technique for determining the stress intensity factor K. The method has been mainly applied to isotropic materials. For anisotropic materials, however, the method has not been much studied. In this paper, the method of caustics is examined for a highly orthotropic unidirectionally reinforced carbonepoxy composite under mode I loading by using a coating technique, and the results are compared with those of finite element analysis. As a result, it was found possible to apply the method of caustics to orthotropic CFRP laminate material.