A research program is in progress to develop strain rate dependent deformation and failure models for the analysis of polymer matrix composites subject to impact loads. Previously, strain rate dependent inelastic constitutive equations developed to model the polymer matrix were incorporated into a mechanics of materials based micromechanics method. In the current work, the micromechanics method is revised such that the composite unit cell is divided into a number of slices. Micromechanics equations are then developed for each slice, with laminate theory applied to determine the elastic properties, effective stresses and effective inelastic strains for the unit cell. Verification studies are conducted using two representative polymer matrix composites with a nonlinear, strain rate dependent deformation response. The computed results compare well to experimentally obtained values.Goldberg, Robert K.Glenn Research CenterDEFORMATION; ELASTIC PROPERTIES; FAILURE ANALYSIS; POLYMER MATRIX COMPOSITES; NUMERICAL ANALYSIS; CONSTITUTIVE EQUATIONS; STRAIN RATE; NONLINEARITY; MICROMECHANICS; LAMINATES; IMPACT LOADS...