Parameter Identification of Constitute Model of Glass Fiber Reinforced Polypropylene under Adiabatic Temperature Rise Loads

To characterize the stress flow behavior of engineering plastic glass fiber reinforced polypropylene (PPGF) commonly used in automotive interior and exterior components, mechanical property is measured using a universal material testing machine and a servo-hydraulic tensile testing machine under quasi-static, high temperature, and high strain rate conditions. Stress versus strain curves of materials under different conditions are obtained. Based on the measured results, a new parameter identification method of the Johnson-Cook (J-C) constitutive model is proposed by considering the adiabatic temperature rise effect. Firstly, a material-level experiment method is carried out for glass fiber reinforced polypropylene (PPGF) materials, and the influence of wide strain rate range, and large temperature span on the material properties is studied from a macroscopic perspective. Then, the model parameters of the J-C constitutive model are identified based on the experimental data, and the influence of the adiabatic temperature rise effect under dynamic tensile conditions is considered. The parameters that can describe the performance of glass fiber-reinforced polypropylene (PPGF) materials are obtained by fitting. Finally, the three-dimensional model of high-speed tension is established using ABAQUS/Explicit finite element software, and calculation is carried out based on J-C model constitutive parameters obtained from the improved identification method. The results show that J-C constitutive model parameters obtained using the improved identification method can describe the stress flow behavior of PPGF materials under large strains, high strain rates, and high temperatures. A method for characterizing the mechanical properties of commonly used engineering plastics in automotive interior and exterior components under high strain rate conditions is established from both experimental and simulation aspects. This method may be used in actual engineering applications.