Modeling of Process Induced Residual Stresses in Resin Transfer Molded Composites with Woven Fiber Mats

ABSTRACT: Cure-dependent mechanical properties are used in finite element-based models to determine process-induced residual stresses and deformations in composite parts. The complete cure cycle in resin transfer molding process is modeled in a series of sub steps. The composite mechanical properties are specified in each step according to the composite cure history. The cool down stage after the composite cure is also analyzed. The effects of resin shrinkage on the development of residual stresses and deformations are investigated as well. Case studies involving composite parts with woven carbon and fiberglass mats and ep-oxy resin are presented to demonstrate the effectiveness of the developed models. Residual stresses were found to be compressive throughout the investigated composite parts. Resin shrinkage resulted in a decrease in residual stresses. The present study establishes the bases for quantifying the combined effects of thermomechanical and thermochemical responses of the material on the development of process induced residual stresses and deformations in resin transfer molded composites