MICROMECHANICAL MODEL FOR COMPOSITES REINFORCED BY LARGE VOLUMEFRACTION OF PARTICLES Ⅰ: ELASTIC ANALYSIS AND EFFECTIVE MODULUS

A micro-mechanical elastic analysis of composites reinforced by a large volume fraction of particles ispursued. A simplified microst ructure model has been suggested. The particles are assumed to be spheres linked byshort cylinders of mat rix material. The displacement component s are assumed to be linearly dist ributed along the axial direction of mat rix cylinders. Micro st resses and micro elastic constant s of a two-particle combination are first deduced for tensile and shear loading cases. Macro elastic constant s for the composite are then obtained by averagingthe micro elastic constant s in various special directions. Thus a relation between micro and macro analyses is const ructed. The model is applied to a metal mat rix composite with two different particle volume f ractions. The predicted elastic properties agree well with the experiment result s. The analysis also reveals that the effect of the particlepacking pattern on the macro elastic properties is t rivial ; however , the dist ribution of micro st resses in differentpacking patterns varies significantly.