Application of decohesive model with mixed damage scale in fracture analysis of composite materials

A decohesive model using a mixed damage scale and using the total fracture energy to simulate the fracture process of composite materials has been developed in this article. The model assumes a bilinear interfacial decohesion function and is incorporated into an interface finite element developed as a user subroutine in the commercial FEA package ABAQUS. In comparison with traditional numerical methods in fracture mechanics, this approach can automatically predict the failure load, crack path and the residual stiffness of bodies undergoing the fracture process. Applications given in this paper are simulation of a typical fracture test with a double cantilever beam (DCB) specimen; modelling a stiffened composite laminated panel under four-point bending and modelling a repaired composite sandwich panel under four-point bending. Good correlation was seen between modelling predictions and experimental results.