ENERGY RELEASE RATE EVALUATION IN SANDWICH COMPOSITE STRUCTURES BY USING THE DIC

Abstract

In this paper a new formalism based on the coupling between the optical full field techniques and the integral invariants is proposed in order to evaluate the fracture parameters in cracked sandwich composite structures. The formalism allows identifying the fracture parameters in terms of energy release rate. From the experimental tests the displacement field is obtained by digital image correlation measurements. In this case the experimental displacement fields are employed to calculate the strain and stress fields by a numerical approach. Then using the mechanical fields defined on the surface of specimen the integral invariants can be used in order to characterize the fracture process. The present study is limited to the identification of the mechanical fields using the experimental displacement fields measured by the optical methods