AN ANALYTICAL AND NUMERICAL STUDY OF THE OVERALL BEHAVIOR OF METAL-MATRIX COMPOSITES

An analytical and numerical study of the overall behaviour of metal-ma trix composites reinforced by particles or short fibres is presented. The particles are elastic and the matrix is elastic-plastic with isotr opic hardening. Cell calculations are performed under the assumption o f continuity of displacements and tractions across the interfaces and are compared with theoretical predictions for the overall stress-strai n curves of the composites derived from a bounding procedure for non-l inear materials. Experimental evidence of the influence of the interfa ce on the overall characteristics of the composite has been given in t he literature. To get some insight into this problem, a model of inter facial degradation is proposed. The influence of the interface propert ies on the overall ductility, through its effect on the deformation of the matrix surrounding the reinforcements, is discussed. Finally, the effects of ductile damage due to void growth in the matrix and to cra cking of the particles are respectively examined.