With the recent increase an composite laminate applications, a number of issues affecting their use have been discovered. In particular, the decrease in buckling load for laminates with interlaminar delaminations is very serious. Accordingly, it is very important to estimate the residual buckling strength after delamination. We attempted a quasi-three-dimensional analysis to clarify this issue. The model is constructed of beam and shell elements. Here the former indicate matrix, the latter indicate fiber, and the deletion of some beam elements indicates interlaminar delaminations. Therefore we confirmed that a quasi-three-dimensional model was very effective for simulating the flexural elastic modulus and buckling strength of a composite laminate with an interlaminar delamination.
