A New Failure Criterion for Nonlinear Composite Materials

A new failure criterion based on the total strain energy density approach is introduced for an equivalent linear elastic material. The total strain energy is composed of the elastic strain energy and the plastic strain energy. The proposed criterion can be used to predict failure of fibrous composite materials subject to uniaxial, biaxial, or multiaxial stress state. The proposed criterion takes into account the different behavior of bimodular composites in tension and compression. Given the stress-strain diagrams in the principal material directions, the failure of the material at any fiber orientation angle under an imposed stress state can be predicted. The results are compared with the corresponding available experimental data. In addition, the predicted failure stresses are compared with those obtained using available failure criteria.