基于非正交本构模型的热塑性机织物预浸料宽温域赋形褶皱缺陷仿真方法

The forming quality of thermoplastic composite preforms directly affects the manufacturing quality of structure. Due to the high melting temperature and viscosity of thermoplastic matrix, unreasonable design of forming process temperature will lead to forming defects such as wrinkles, which brings challenges to high-quality forming of thermoplastic composite structures. Currently, the existing researches on thermoforming of thermoplastic prepregs are mainly based on the continuous, the discrete and the semi-discrete approaches, the anisotropic large deformation behavior of thermoplastic prepreg is analyzed by establishing a multi-mechanism coupled constitutive model, which is not fully considered the influence of process control on wrinkle defects during forming macroscopic deformation. In this paper, a simulation method of forming wrinkle defects in thermoplastic prepregs in a wide temperature range was developed. By characterizing the mechanical properties of thermoplastic woven fabric prepregs at different temperatures and loads, the non-orthogonal constitutive model parameters of thermoplastic prepregs in a wide temperature range were obtained. The effect of temperature on forming wrinkle defects in thermoplastic prepregs was proposed, and the deformation mechanism of wrinkle defects in a wide temperature range in the forming process was revealed, and the optimal control scheme of forming temperature was obtained. The research results show that the initiation and evolution of wrinkle defects has been affected by the in-plane shear and compressive deformation behaviors at different temperatures, the deformation degree of wrinkle defects of prepreg has been decreased with the increase of temperature. The simulation results of the non-orthogonal constitutive model are basically closer to the experimental results.