Process-Induced Stress and Deformation in Thick-Section Thermoset CompositeLaminates

摘要

A study of process-induced stress and deformation in thick-section thermosettingcomposite laminates is presented. A one-dimensional cure simulation analysis is coupled to an incremental laminated plate theory model to study the relationships between complex gradients in temperature and degree of cure, and process-induced residual stress and deformation during cure. Thermal expansion and cure shrinkage contribute to changes in material specific volume and represent important sources of internal loading included in the analysis. Temperature and degree of cure gradients that develop during the curing process represent fundamental mechanisms that contribute to stress development not considered in traditional residual stress analyses of laminated of laminated composites. Model predictions of cure dependent epoxy modulus and curvature in unsymmetric graphite/epoxy laminates are correlated with experimental data. The effects of processing history (autoclave temperature cure cycle), laminate thickness, resin cure shrinkage and laminate stacking sequence on the evolution of process-induced stress and deformation in thick-section glass/polyester and graphite/epoxy laminates during cure are studied. The results clearly indicate that the mechanics and performance of thick-section thermoset laminates are strongly dependent on processing history.