关键词: 弹塑性, 接触冲击, 冲击角, 动力学建模, 恢复系数

Abstract: For the elasto-plastic contact-impact problems of a vertical rod-like structure impacting the fixed oblique flat surface, the dynamics equations of the rod-like structure and the formulations of instantaneous contact forces in each phase during contact-impact events were established, and the various laws of the motion parameters and the contact forces were systematically studied in detail. Using ODE45 function, the time-variation laws such as the kinetic energy of the rod-like structure, position and velocity of the contact point, angle and angular velocity of the rod-like structure were analyzed. Besides, the relationships between the coefficient of restitution and the initial impact velocity, and the permanent deformations depending on initial impact velocity, as well as the contact forces with the contact deflection, were also achieved by the numerical analyses. The results show that the higher the initial drop height, the shorter the contact-impact time and the more obvious the rebounding phenomenon. And the contact force vs. contact deflection curves show similar trends with increasing initial drop height, but the permanent deformations are closer to the maximum deformation. Contact-impact tests were performed by dropping the vertical rounded ended rod-like structure from different initial drop heights on the fixed oblique flat surface with the inclination angle of 45°, and then, combined with testing data for the coefficient of restitution and permanent deformation in normal impact events reported in literatures, the comparative analysis results show that the simulation results are basically match with the testing results, which is verified the accuracy of the established model.

Key words: elasto-plastic, contact-impact, impact angle, dynamics modelling, coefficient of restitution