AN ANALYTICAL STUDY OF THE INFLUENCE OF THERMAL RESIDUAL-STRESSES ON THE ELASTIC AND YIELD BEHAVIORS OF SHORT-FIBER-REINFORCED METAL-MATRIXCOMPOSITES

An analytical model was developed to study the influence of thermal re sidual stresses on the elastic and yield behaviors of aligned short fi ber-reinforced metal matrix composites. Three-dimensional solutions of elastic stress field in the matrix of a circular cylindrical unit cel l were first obtained based on the theory of elasticity. On this basis , an alternative analysis of the stress transfers between the matrix a nd the fiber was given by using the shear lag analysis, which provides the expressions for the stress distributions in the matrix and the fi ber. The thermal residual stresses and the distributions of the stress es under tensile and compressive loadings as a function of the materia l parameters, such as fiber volume fraction, fiber aspect ratio and ma trix yield stress, were calculated. Furthermore, simple expressions fo r the composite elastic modulus and yield strength under tensile and c ompressive loadings were derived. These expressions were used to study the influence of the thermal residual stresses and the material param eters on the elastic moduli and yield strengths under tensile and comp ressive loadings. Finally, the model predictions were compared with th e experimental results on the SiCw/Al-Li T6 composite and several SiCw /Al T6 composites in literature and also with the other theoretical mo dels. (C) 1998 Elsevier Science S.A. All rights reserved.