关键词: 聚脲材料, 分离式 Hopkinson 压杆试验, 动态力学性能, 本构模型

Abstract: To study the fiber-reinforced polyurea material, dynamic mechanical property experiments were conducted using a separated Hopkinson pressure bar. Stress-strain curves for specimens at three different temperatures and various strain rate ranges were obtained. A visco-hyperelastic constitutive model based on the standard linear solid model was established. The experimental results show that the dynamic mechanical response of fiber-reinforced polyurea is nonlinear, with the stress-strain curve consisting of a super-stress region and a hyperelastic region. As the strain increases, the super-stress value tends to stabilize, and the nonlinear term associated with strain rate in the constitutive model also gradually approaches a stable value related to the strain rate. The visco-hyperelastic constitutive model based on the standard linear solid model can accurately describe the dynamic mechanical behavior of fiber-reinforced polyurea. The constitutive model was implemented through secondary development in LS-DYNA for simulation. In both SHPB simulation and air blast simulation, the simulation results are in good agreement with the experimental data, validating the accuracy of the constitutive model.

Key words: Polyurea materials, separated Hopkinson pressure bar test, dynamic mechanical properties, constitutive model