CRACK EXTENSION IN UNIDIRECTIONAL COMPOSITE LAMINAE

The problem of predicting the crack extension behaviour of a centre-no tched unidirectional graphite-epoxy coupon is investigated. Both the l oad required to cause initial crack growth and the direction of crack growth are of interest. Comparison between the theoretical predictions and the experimental results indicates that the present criterion, ba sed on the critical strain energy, accurately predicts the direction o f crack growth as well as the load causing crack growth initiation for the test cases considered.