A TRANSFORMATION-FIELD ANALYSIS OF THERMOMECHANICAL STRESSES IN PARTICULATE METAL-MATRIX COMPOSITES

Microstress fields in particulate metal-matrix composites during cooling from the fabrication to room temperature are investigated. The analysis is based on the transformation-field method recently proposed by Dvorak (1992, Proc. R. Sec. tendon A437, 311-327) for modeling the inelastic behavior of composite materials. A simple unit-cell model of a composite sphere is employed to describe the microgeometry of the medium. It is demonstrated that the method, together with the solutions of some auxiliary boundary-value problems, provides an efficient tool for the evaluation of local fields in the representative volume. In addition, the mechanical load is considered. A remarkable feature of the formulation is that the transformation concentration factors can be resolved analytically, which greatly reduces the computation time, Numerical examples are presented for two potential composite systems. Successive distributions of local stresses versus the temperature change in the elastic-plastic expansion are illustrated.