Transverse failure in thick S2-glass/epoxy fiber-reinforced composites

The transverse mechanical and failure behavior of unidirectional S2-glass/epoxy composites are investigated and reported for a wide range of strain rates from 10(-4) to 10(4) S-1 under multiaxial compressive loading conditions. The effect of stress multiaxiality is explored using the confining sleeve technique to impose varying degrees of lateral confinement. The lateral confinement has been found to significantly increase both the maximum attainable stress level and the strain to failure. Scanning electron microscopy (SEM) observations oil recovered specimens reveal that the transverse failure occurs within localized shear bands through multiple fiber-matrix interface failure at the micro-scale. Based on the orientation of shear bands a Mohr-Coulomb type failure criterion is suggested to represent the transverse failure of unidirectional S2-glass/epoxy composites.