Modeling of process induced residual stresses in resin transfer molded composites with woven fiber mats

Cure-dependent mechanical properties are used in finite element-based model s to determine process-induced residual stresses and deformations in compos ite parts. The complete cure cycle in resin transfer molding process is mod eled in a series of sub steps. The composite mechanical properties are spec ified in each step according to the composite cure history. The cool down s tage after the composite cure is also analyzed. The effects of resin shrink age on the development of residual stresses and deformations are investigat ed as well. Case studies involving composite parts with woven carbon and fi berglass mats and epoxy resin are presented to demonstrate the effectivenes s of the developed models. Residual stresses were found to be compressive t hroughout the investigated composite parts. Resin shrinkage resulted in a d ecrease in residual stresses. The present study establishes the bases for q uantifying the combined effects of thermomechanical and thermochemical resp onses of the material on the development of process induced residual stress es and deformations in resin transfer molded composites.