EFFICIENT MODELING OF POSTBUCKLING DELAMINATION GROWTH IN COMPOSITE LAMINATES USING PLATE ELEMENTS

Under compression, delaminated composite plates may undergo postbuckli ng that can lead to delamination growth. The use of three-dimensional finite elements for the calculation of the strain energy release rate at the delamination front is computationally expensive. The Mindlin pl ate finite element is used to perform the postbuckling analysis and to compute the strain energy release rate at the delamination front with the aid of the crack closure method. Comparison of the present strain energy release rate calculation with the existing three-dimensional r esult indicates that the present method is efficient and accurate. For stationary delamination cracks, the effects of stacking sequence and shape of delamination are examined, A procedure of determining delamin ation front location for a propagating delamination is presented. Dela mination growth initiated from embedded and edge delaminations is inve stigated using this procedure.