Multiscale analysis and process parameters optimization of residual stress/strain of 3D woven composite

Abstract

To predict the process-induced residual stress/strain of 3D woven composite and propose the optimal cure cycle, a multiscale model of the process analysis has been developed. Based on the representative volume elements (RVE) at the fiber and yarn scale, the modulus development of yarns and 3D woven composite was obtained. A thermal-chemical-mechanical coupling analysis was conducted on the yarn scale with the consideration of chemical shrinkage effect of resin, and the evolution of the microscopic stress-strain was calculated. The fiber Bragg grating (FBG) sensors were embedded in the 3D woven preform through the 3D weaving technique, and the evolutions of temperature and strain were monitored. The accuracy of the finite element model was validated by the experimental result. Three sequential sampling methods based on space, error and result were adopted to establish the surrogate model of the process analysis of 3D woven composite. Based on the surrogate model, the optimization of process parameters of 3D woven composite forming process was carried out. The results show that the residual strain is reduced by 15.4% and the cure cycle is shortened by 10.6%.