A Failure Criterion for Composite Materials

A failure criterion for composite materials based upon the strain invariants of finite elasticity is introduced. The failure criterion assumes that the material is transversely isotropic and that failure occurs when the strain energy density reaches its maximum value. The failure criterion is further simplified by assuming that the fiber and matrix failure modes can be decoupled. An experimental test is proposed for determining the failure surface. A special case, the failure criterion for infinitesimal-strain elasticity theory, is introduced. The failure surfaces in the strain invariants' space are determined for two composite materials.