Mixed-mode failure of graphite/epoxy composites

An experimental study of the crack displacement and failure modes of graphi te epoxy-plates, having central cracks at different angle with the loading axis, was conducted. Due to this type of loading arrangement, the material was under mixed-mode loading condition (Mode I and mode II). IN this invest igation, Moire Interferometry technique was employed to measure Crack Openi ng Displacement (COD) and Crack Shearing Displacement CSD). Detailed studie s were performed to investigate the effect of the crack angle on the streng th reduction ratio, the damage zone, and the critical stress intensity fact ors. The comparison between the Linear Elastic Fracture Mechanics (LEFM) so lution and the results obtained from this investigation showed a fair agree ment between the theoretical data and the experimental ones. This confirms the validity of implementing the LEF model for this type of materials.