Prediction of residual stresses and distortion in carbon fiber-epoxy composite parts due to curing process using finite element analysis

Abstract

To predict the final geometry of carbon fiber-epoxy composite parts, a methodology is introduced that takes into account cure kinetics, cure shrinkage, thermal strains, tool-part interface, and development of mechanical properties during cure. These parameters affect process-induced residual stresses and distortion in the parts. A module was developed for each mechanism and a fully 3D coupled thermomechanical finite element analysis was utilized. To validate the simulation results, a square composite panel was fabricated and its pattern of distortion was obtained. The simulated distortion pattern agreed well with the actual pattern obtained from the experiments. Parallel processing and optimization of the developed codes were used resulting in 94% reduction in the computational time. The proposed methodology proved to be accurate and time-efficient in predicting the final geometry of the parts.