INFLUENCE OF THERMAL RESIDUAL-STRESSES ON THE COMPOSITE MACROSCOPIC BEHAVIOR

The influence of the thermal residual stress on the deformation behavi or of a composite has been analyzed with a new micromechanical method. The method is based on secant moduli approximation and a new homogeni zed effective stress to characterize the plastic state of the matrix. It is found that the generated thermal residual stresses after cooling and their influence on the subsequent deformation behavior depends si gnificantly on the aspect ratio of the inclusions. With prolate inclus ions, the presence of thermal residual stresses generate a higher comp ressive hardening curves of the composite, but it is reversed with obl ate inclusions. For particle reinforced composite, thermal residual st resses induce a tensile hardening curve higher than the compressive on e and this is in agreement with experimental observations. (C) 1998 El sevier Science Ltd.