Modeling Inter-Laminar Failure in Composite Structures: Illustration on an Industrial Case Study

This paper presents a solution procedure made available at an industrial level to study delamination in composites. Two approaches are presented. The first one is based on an original VCE (Virtual Crack Extension) method used to provide a quick estimate of the propagation load and the critical inter-laminar cracks, in a linear finite element analysis. The second approach relies on cohesive elements, and implies a non linear analysis. More general than the fracture mechanics (VCE) approach, the cohesive elements technique allows to provide the value of the maximum load that can be sustained by the structure, and to predict the residual strength and stiffness over the fracture process. Those two methods are first compared in a DCB test case to show that the results agree well with those from the literature or with the analytical solutions. Finally, a multi-delaminated industrial test case is solved with both approaches.