Delamination of multidirectional composite laminates at 0°/Theta° ply interfaces

Abstract

The main objective of this study is to determine test and analysis methods suitable for establishing delamination propagation criteria of non-unidirectional laminates. The crack interface was chosen to be 0°/45° and the tests were focused on obtaining the mode I fracture toughness (GIC). The widely used DCB test was avoided due to anticipated problems with intralaminar damage developing at the ply interface of interest. The ADCB and AMMF methods were used to determine the mode I fracture toughness (GIC) with the amount of mode I close to 100%. The selected stacking sequence resulted in desirable crack propagation behavior; there was no change of delamination plane, an acceptable crack front profile, no initial specimen curvature, and no energy dissipation through global specimen damage. Finite element simulation was found to be the only tool capable of analyzing the experimental data.