球-梁弹塑性次碰撞的试验研究和数值仿真

发布时间：2018-05-13 10:06

本文选题：梁 + 次碰撞　；参考：《机械工程学报》2016年19期

【摘要】：次碰撞是柔性结构碰撞时特有的物理现象。为观测和深入研究这一现象,专门研制了一套柔性结构次碰撞试验平台。借助该试验平台,结合Hertz碰撞理论和动态子结构方法,对钢球坠落碰撞简支梁过程进行了详细的试验测试和数值仿真,观察到了复杂的次碰撞现象,深入探讨了次碰撞的碰撞接触时间规律和主要影响因素。研究结果表明,动态子结构方法可以作为球-梁弹塑性次碰撞行为分析的一种有效的数值计算手段。研究发现,在低速碰撞时Hertz碰撞理论所揭示的碰撞接触时间规律仍然适用于首个次碰撞过程,表明局部接触变形主导了首个次碰撞过程。次碰撞现象一旦发生,将导致简支梁碰撞端位移响应的前三阶振幅比和第一阶相位角均发生明显的变化。进一步的探讨则发现,次碰撞的发生与球-梁质量比、碰撞初速度和碰撞位置等因素密切相关,若用质量比来度量次碰撞的发生条件,发现存在一个质量比阈值,只有满足该质量比阈值,才会出现次碰撞。
[Abstract]:Secondary collision is a special physical phenomenon of flexible structures. In order to observe and study this phenomenon, a subimpact test platform for flexible structures is developed. With the help of the test platform, combined with the Hertz collision theory and the dynamic substructure method, a detailed experimental test and numerical simulation of the steel ball fall impact simple supported beam process have been carried out, and the complex secondary collision phenomenon has been observed. The contact time law and main influencing factors of secondary collision are discussed. The results show that the dynamic substructure method can be used as an effective numerical method for the analysis of the elastic-plastic secondary collision behavior of a spherical beam. It is found that the contact time law revealed by the Hertz collision theory is still applicable to the first collision process in low speed collisions, indicating that the local contact deformation dominates the first collision process. Once the secondary collision occurs, the first three order amplitude ratio and the first order phase angle of the displacement response at the impact end of the simply supported beam will change obviously. Furthermore, it is found that the secondary impact is closely related to the mass ratio of the ball to beam, the initial velocity and the position of the collision. If the mass ratio is used to measure the occurrence conditions of the secondary collision, a mass ratio threshold is found. Only when the mass ratio threshold is satisfied will secondary collisions occur.
【作者单位】：安徽工业大学机械工程学院;南京理工大学理学院;
【基金】：国家自然科学基金(11372138,10872095) 高等学校博士学科点专项科研基金(2012321910036) 安徽高校省级自然科学研究(KJ2013Z021)资助项目
【分类号】：O313.4

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