热塑性预浸料赋形褶皱缺陷的全局灵敏度分析

Wrinkles are easily produced during the forming process of complex composite structures, which affect the forming quality and load-bearing performance of the components. It is urgent to establish the quantitative mapping relationship between forming process parameters and prepreg wrinkles to support the low-defect forming manufacturing of components. In this paper, a global sensitivity analysis method for wrinkled defects in thermoplastic prepregs coupled with multiple process parameters is proposed. A finite element simulation method based on a non-orthogonal constitutive model is developed for the wide temperature domain deformation of thermoplastic prepreg. Combining the distance between the prepreg and the mold and the curvature of the out of plane bending of the prepreg improves the reliability of quantitative characterization of crease defects. Finally, a global sensitivity analysis method was established using the Sobol global sensitivity index based on variance, which can quantitatively calculate the impact of forming process parameters on wrinkle defects. It is verified through the typical carbon fiber/polycarbonate (CF/PC) material single dome forming process. The results show that in the temperature range of 200-250℃ and the pressure range of 0.2-2.0 kPa, the influence of temperature on the wrinkling defects of CF/PC prepreg is greater than that of pressure, and there is a dual parameter coupling effect of temperature and pressure during the forming process.