INFLUENCE OF RANDOM BRIDGING ON THE ELASTIC AND ELASTOPLASTIC PROPERTIES OF FIBER-REINFORCED COMPOSITES

The overall elastic moduli and elastoplastic stress-strain relations o f a fiber-reinforced composite containing either aligned or randomly o riented spheroidal voids are derived explicitly. The results are given in terms of the void shape and concentration, and for the elastic mod uli the void shape is further pushed to the limit for cracked bodies. The present theory also corresponds to the condition of ''random bridg ing'', with a longitudinal Young's modulus and axial shear modulus lyi ng between those of ''full bridging'' and ''no bridging''. Numerical r esults further indicate that both elastic and elastoplastic strength o f the fiber-reinforced composite can be significantly weakened by the presence of both types of distribution, but the extent of stiffness or strength reduction is highly dependent upon the void shape and loadin g direction.