Delamination growth during pre- and post-buckling phases of delaminated composite laminates

The delamination growth during the pre-or post-buckling phases in composites with a single delamination (one-dimensional model) is investigated. For that purpose, a general nonlinear analysis, using variational principle, with a new set of relations for the decomposition of the total energy release rate, is used for an arbitrary one-dimensional composite laminate structure. A computer code is developed and used for the parametric study of delamination growth during buckling. The effects of a wide range of parameters, like imperfection, layup, location of delamination, theory type and length-to-thickness ratio, were intensively studied. It is found that a dominant parameter, in terms of the level of energy release rate, is the length-to-thickness ratio. (C) 1997 Elsevier Science Ltd.