Variational analysis of transverse cracking and local delamination in [θm/90n]s laminates

A displacement-based variational model is developed to study the effects of transverse cracking and local delaminations in symmetric composite laminates. In the model, the crack shape is assumed to be a function of crack density and delamination length. Using a variational approach with the principle of minimum potential energy, governing equations are derived. The effective Young’s modulus Ex and energy release rate G are theoretically examined as a result of local delaminations.