EFFECTIVE ELASTIC RESPONSE OF 2-PHASE COMPOSITES

We present finite element analyses of the overall elastic properties o f two-phase composites as a function of the shape, concentration and s patial distribution of the reinforcement. The analyses of the geometri cal effects of constituent phases on the overall elastic moduli have b een carried out within the context of axisymmetric and plane strain un it cell formulations. In most calculations, the phases are taken to be isotropic and linear elastic, and the interface perfectly bonded. The se finite element results are compared with available analytical resul ts for a variety of geometrical arrangements of the constituent phases of the composites. Computations which predict the effective elastic p roperties for the limiting case where all the reinforcing particles fr acture are carried out. The competition between stiffening due to rein forcement and increased compliance due to cracking of the reinforcemen t is evaluated for metallic, ceramic and intermetallic matrices with b rittle reinforcements, and the numerical results are compared with ana lytical solutions. The paper also includes discussions of the role of thermal residual stresses in influencing apparent initial moduli and t he effects of interfacial compliance on the stress distribution within the reinforcement.