Prediction of three-dimensional composite laminate response using micromechanics of failure

A three-dimensional micromechanics of failure model was developed and applied in order to predict triaxial failure envelopes and stress–strain curves for 12 test cases in the Second World-Wide Failure Exercise (WWFE-II), which involves five continuous fiber–matrix laminates and multi-axial loadings, including those in through-thickness direction. The micromechanics of failure is based on micromechanical unit cell models, which characterize the microstructure of composites, and consists of independent constituent failure criteria and a progressive damage model for the matrix. Nonlinear ply behavior in the matrix-dominant directions was successfully simulated. Thermal stresses were also considered. Results of prediction were presented together with an explanation of the phenomena.