Creep-damage interaction in composites

Experimental results and theoretical prediction of the response of glass-fiber reinforced polyester under quasi-static, creep, and fatigue loading are presented. Non-linear strain component at static loading and strain amplitude rate at cyclic off-axis loading for the orthotropic composite are shown to follow the associated flow rule with a single-parameter quadratic potential function. The influence of fatigue damage on deformation is essential by reducing the elastic modulus of the composite and apparently negligible by its effect on creep kernel parameters.