关键词: Q345E舰船钢, 静动态力学性能, 本构模型, 断裂模型, 高速穿甲

Abstract: In order to characterize the mechanical response of Q345E steel under high-speed impact conditions, quasi-static tensile and Hopkinson compression experiment were conducted to determine the static and dynamic mechanical properties of Q345E steel as well as its fracture characteristics in wide stress triaxiality. Based on the Johnson-Cook and Cowper-Symonds models, a JC-CS constitutive model was proposed to characterize the static and dynamic mechanical behavior of Q345E steel. The three-stage Wierzbicki failure model and the failure parameters were obtained by experiment and numerical simulation. The ABAQUS-VUMAT subroutine was used to verify the validity of the constitutive and failure model. The results show that Q345E steel has obvious strain hardening and strain rate effects. The two kinds of effects are coupled under dynamic loading, and the proposed JC-CS constitutive model can accurately characterize the rate-dependent strain hardening and strain rate effects in the range from quasi-static to high strain rate. The fracture strain of Q345E steel is related to the stress triaxiality. When the stress triaxiality is greater than -1/3 and less than 2, the fracture strain decreases, increases, and then tends to zero. The fracture strain is infinite when the stress triaxiality tends to -1/3. The numerical simulation results, based on material experiment and high-speed perforation experiment, demonstrate a high level of agreement between the fracture morphology, failure mode of the plates and multi-layer targets perforating predicted by the simulation and the experimental results. This indicates that both the established JC-CS constitutive model and Wierzbicki failure model effectively capture the fracture behavior of Q345E steel as well as its response characteristics under high-speed perforation.