Quasi-Three-Dimensional Crack Tip Element Analysis for Evaluation of Total Energy Release Rate in Composite Laminates

Abstract

An analytical quasi-three-dimensional crack tip element model is developed to provide a quick assessment of the delamination behavior for composite laminates. A closed-form solution for the average total strain energy release rate is obtained by taking into consideration of all the displacement components defined in the classical laminated plate theory. By means of numerical experiments, it is shown that the presented method can predict the average total strain energy release rates with satisfactory accuracy for a relatively large variety of composite layups under opening and in-plane-shearing loading conditions. It indicates that the influence of out-of-plane transverse displacements on the total energy release rate can be significant for certain type of layups even under in-plane loading conditions. Furthermore, an orthotropic parameter is introduced to represent the influence of out-of-plane transverse effects.