Residual strength-based life predictions of composite materials under combined damage mechanisms

We seek a method by which the residual strengths of composites subjected to combined degradation mechanisms may be calculated. Three different approac hes are considered. First, the inputs to the residual strength analysis are purely phenomenological. Second, we make use of a micromechanics-based sim ulation to combine the effects of two specified damage mechanisms. Finally, we develop a hybrid approach in which the results from the micromechanics simulations for individual mechanisms are used as inputs to the residual st rength model as if they had been obtained from experimental data. The resid ual strength model is then used to predict the combined behavior, and the r esults are compared with those obtained directly from the simulations. For the two mechanisms considered (slow crack growth and asperity creep), the r esults for the detailed micromechanical simulations were accurately represe nted by the residual strength-based model.