A unified cohesive zone model for simulating adhesive failure of composite structures and its parameter identification

It has been proven that the shape effect of different cohesive laws can not be ignored in many cases. Such an effect is further investigated and clarified in the present paper. In order to more accurately simulate the adhesive failures of composite structures, it is necessary to develop a unified cohesive zone model (CZM) capable of approaching an arbitrary existing cohesive law. Toward this end, an improved interpolation-based CZM (ICZM) has been developed. The parameters of such a model were generally obtained by inverse analysis. However, success of the inverse analysis greatly depends on the initial guess of model parameters and its analysis technique. Therefore, a two-step inverse analysis method, perfectly matching the present ICZM, has been further developed in our work. The verifications based on both pseudo-experimental and real experimental data have shown that the present developed model and method are robust and can uniformly describe various adhesive failures without need to consider selection of appropriate CZM for different types of fracture problems. Finally, a novel inverse analysis method in combination with two types of experimental information, has been developed to improve the solution reliability and relieve the ill-posed extent of inverse problems.