Data underlying the research of Cure-induced residual stresses for warpage reduction in thermoset laminates

The paper addresses the role played by the cure stage of a vacuum assisted resin transfer molding process (VARTM) in residual stresses generation. The Airstone 780E epoxy resin and Hardener 785H system broadly used in the wind turbine blade industry has been used in this study. The viscous-elastic properties of the resin have been characterized and implemented in a thermo-mechanical FE model. The model has been validated against manufactured laminates. Analysis of residual stresses generation highlighted that compressive stresses generation occurs when the cure is shrinkage dominated and tensile stresses when expansion dominated. The finding points out that 14% reduction in compressive residual stress level and 33% reduction in process time can be obtained by selecting cure cycle parameters that allows tensile stresses development during the cure process