Evolution and influence of residual stresses/strains of fiber reinforced laminates

This paper presents a meso/micromechanical study of fiber reinforced polymeric matrix cross-ply laminates during and after a high temperature curing process. The emphasis is on the generation and evolution of the curing induced residual stress/strain and their influence on the response under subsequent mechanical loading. The cross-ply laminate is modeled by a representative volume element and the constituent materials are described by an elastic model for the fiber and a non-linear viscoelastic model for the polymer matrix. The residual stress/strain fields at the ambient temperature immediately following the cool-down and their evolution with time are determined through the viscoelastic finite element discretization of the RVE with a special consideration given to the fiber/matrix interface region. The results indicate that the residual stresses decrease with time and tend to small asymptotic values after about 34 h. However, the remaining residual strains still have significant influence on the damage evolution of the cross-ply laminate under subsequently superimposed tensile loading.