An analytical study of the influence of thermal residual stresses on the elastic and yield behaviors of short fiber-reinforced metal matrix composites

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