Novel criteria for strength predictions of open-hole composite laminates for preliminary design

In this work a novel modification of the well-known Whitney-Nuismer criteria is proposed with the aim of having a simple and yet accurate fracture criterion for the important problem of estimating the strength of composite laminates with circular open-holes. The novelty is the use of a critical path curve that makes the proposed criteria quite general and provides very good correlation with experimental data for a wide range of laminates and hole sizes even when the characteristic lengths are assumed as material constants. This assumption dramatically reduces the amount of required experimental testing making these criteria very suitable for preliminary design.