Mesh-independent modeling of both distributed and discrete matrix cracking in interaction with delamination in composites

A finite element model is presented for failure analysis of composite laminates with the phantom node method for matrix cracking and interface elements for delamination. The phantom node method allows for mesh-independent representation of straight intraply cracks in laminates. In laminates two different phenomena that both involve such cracks are distinguished, namely distributed matrix cracking and discrete splitting, where the transition between the two is related to delamination. It is investigated how both phenomena and their transition can be represented in a single computational framework. Objectivity of the results with respect to element size and the introduced crack spacing parameter is examined.