Abstract
Because interface failure has been a common failure mode in reinforced composite materials, the authors investigated the micromechanical interface stress distribution and potential failure in fibrous composite materials under transverse loading, using the boundary element method. Both normal and tangential interface stresses were computed around fibres of different geometrical shapes and volume fractions. In addition, interface stresses around fibres located deep inside of a composite specimen or at the boundary of the specimen were calculated and compared. This study examined the interface failure initiation and growth for various cases as described above. The quadratic failure criterion, based on the interface normal and shear stresses, was considered at the interface to compare the failure under different cases. The effect of progressive interface failure on the composite stiffness was also studied for different cases, as mentioned above.