Numerical and experimental study of delamination in laminated composites

In this study, delamination growth in a double cantilever beam (DCB) specimen, which is used to measure critical strain energy release rate under a mode I type of loading, was investigated experimentally and numerically. In addition, delamination growth in mixed mode beam (MMB) specimens was tested to measure critical strain energy release rates under mixed mode I and mode II types of loading and fatigue tests were conducted on tapered laminates.The material in all cases was carbon fiber reinforced epoxy. The laminates were manufactured from UD (Unidirectional) carbon tapes. Delamination growth was simulated with a fracture mechanics approach, virtual crack closure technique (VCCT), using the finite element method. In order to implement the VCCT method element?killing strategy was used. This provided a means to handle moving meshes during delamination propagation. Simple tension tests and three point bending tests were conducted as well to determine basic material properties.