三维机织复合材料残余应力/应变多尺度分析及工艺参数优化

为预测三维机织复合材料工艺引入的残余应力/应变,提出工艺制度优化方案,建立了一种工艺过程分析的多尺度模型.通过建立纤维尺度及纱线尺度代表体元(RVE),计算了成型过程中纤维纱线及三维机织复合材料的模量演化历程.考虑固化过程中树脂的化学收缩效应,在纱线尺度上开展热-化学-力学耦合分析,预测了细观残余应力-应变及其演化规律...

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

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%.