BOUNDS ON ELASTIC-MODULI OF UNIDIRECTIONAL COMPOSITES WITH IMPERFECT BONDING

Starting from the homogenization technique for periodic media, the present work aims to evaluate the effective elastic moduli of continuous-fiber-reinforced matrix composites, in which slipping between the constituents occurs. The interface degradation is modeled by a tangential slip without any normal debonding. It may be elastic, viscous or viscoelastic. The method developed consists of building statically admissible stress fields, which allow one to obtain analytical expressions for the estimates of the elastic effective moduli. Previously obtained upper bounds and the present lower bounds are compared with each other and with results found in the literature.