XFEM-VCCT for Composite Delamination

Cohesive Element Method (CEM), the most popular method for composite delamination, suffers from rigorous element size requirements and great computational cost. In this work, the Extended Finite Element Method (XFEM) and Virtual Crack Closure Technology (VCCT) are combined to develop XFEM based on VCCT (XFEM-VCCT) for delamination analysis for the first time. In XFEM-VCCT, the geometry of delamination is represented by XFEM with VCCT as the delamination propagation criterion. A new method for the strain energy release rate in the frame of XFEM is created based on Irwin’s integration. The XFEM-VCCT is applied to three examples to validate. Through the three examples, some outstanding advantages of XFEM-VCCT show up compared with CEM. First, XFEM-VCCT can simulate delamination and its propagation without remeshing, thus simplifying the mesh work. Second, XFEM-VCCT does not require such a fine mesh as CEM, alleviating the element size requirement. Lastly, ignorant of material property degradation, iterations are not needed and the computational efficiency is greatly improved. Therefore, the newly developed XFEM-VCCT can provide more accurate results with simpler mesh work and less computational cost for composite delamination, compared with CEM.