THE EFFECT OF MATRIX CONSTITUTIVE MODEL ON RESIDUAL THERMAL-STRESSES IN MMC

A thermomechanical analysis of advanced composites in a wide temperatu re range is presented. This analysis is based on the micromechanics me thod of cells. An incremental formulation of the micromechanics model is developed to facilitate the use of various inelastic constitutive t heories. These theories incorporate time-dependent and temperature-dep endent features for modeling different types of metal matrices. The co nstitutive models include the Bodner-Partom unified theory of viscopla sticity, the incremental plasticity model, and a power-law creep model . The effect of the cooling rate, faking into account temperature-depe ndent matrix properties, on residual thermal stresses is subsequently investigated for a SiC/Ti composite using the different models for the matrix phases. Predictions generated using the micromechanics method are compared with available results of finite-element analysis.