Comparison among methods for identification of CZM parameters from ENF test

The knowledge of fracture behavior of adhesive joints is crucial in the design of new structural elements or in retrofitting existing ones. Cohesive zone model (CZM) is a robust approach to describing the interface behavior of bonded joints. This paper deals with a comparison of direct and inverse methods for identification of CZM law parameters under mode II of fracture, considering the same formulation for the evaluation of the strain energy release rate (ERR) based on the J-integral approach. The obtained traction-separation laws were used for predicting the decohesion process by finite element analyses of an end notched flexure (ENF) test. Numerical responses of virtual test, in terms of load-displacement curve and adhesive tangential displacement trend, were compared with experimental data. Differences between direct and indirect methods were addressed to point out adequateness of such methodologies in the assessment of bonded joint decohesion process in mode II.