Reliability of Composite Laminates Through a Damage Tolerance Approach: Applications into Carbon-Epoxy and Glass-Epoxy Composite Shells

Abstract

In the present paper, the damaged mechanical behaviour of carbon-epoxy and glass-epoxy composite shells has been characterised into quasi-static conditions, under different uniaxial or biaxial loadings. The experimental data obtained through different tests upon [±55°]3 glass-epoxy laminates and upon [±55°]3, [±35°]3, [±75°]3 carbon-epoxy shells have been compared with the numerical results based on a damage-elastoplastic theoretical model. This damage model has been developed by introducing damage and elastoplastic parameters into layer constitutive equations. In particular, a tensor quantity has been introduced, able to simulate damage in the elastoplastic field and to describe the new stress distribution into layers. The resulting strongly non-linear set of equations requires numerical solution, since generally, the mechanical characteristics of the layers result function of their position into laminate shell, and depending on damage through its characteristic tensor variable.