PREDICTION FOR DELAMINATION INITIATION AROUND HOLES IN SYMMETRICAL LAMINATES

The purpose of this paper is to present an analytical technique for predicting the delamination initiation load and delamination location for balanced symmetric laminates containing a hole. Basically, this approach includes two phases. First, the stress distribution around the hole region is calculated by the authors' recently developed efficient method. Second, the delamination initiation load and delamination location are predicted by using an average stress failure hypothesis together with the Hashin-Rotem delamination criterion. A computer program was developed to calculate the delamination initiation load and location for notched laminates with different ply orientations, different material properties and different stacking sequences. Numerical results for (theta/- theta/0-degrees)s, and (0-degrees/90-degrees)s composite laminates generated by the current approach are compared with existing solutions. The results show that the present method is very efficient and useful for the purpose of engineering design.