钢球与简支梁的次碰撞研究  

STUDY OF SUB-IMPACTS IN SIMPLY SUPPORTED BEAM STRUCK BY STEEL SPHERE

作　　者：戚晓利[1,2] 尹晓春[1] 杨海波[1] 金腾飞[1] 

机构地区：[1]南京理工大学理学院,南京210094 [2]安徽工业大学机械工程学院,马鞍山243002

出　　处：《机械强度》2015年第1期45-51,共7页Journal of Mechanical Strength

基　　金：国家自然科学基金面上项目(11372138;10872095);高等学校博士学科点专项科研基金项目(2012321910036);安徽高校省级自然科学研究项目(KJ2013Z021)资助~~

摘　　要：采用自行研制的一套柔性结构次碰撞实验平台和配套搭建的次碰撞瞬态测试系统,对钢球坠落碰撞简支钢梁过程进行了详细的实验测试。在此基础上,结合赫兹碰撞理论和数值仿真方法,深入探讨和研究了碰撞过程中出现的次碰撞现象。研究结果表明:(1)首个次碰撞过程的碰撞持续时间与Hertz碰撞时间相吻合;(2)后续次碰撞与首个次碰撞过程不同,其碰撞持续时间围绕Hertz碰撞时间作随机变化,但在总体趋势上依然符合赫兹碰撞理论;(3)研究表明,看似随机、对结构瞬态响应敏感、十分复杂的次碰撞过程,本质上受到局部接触变形所主导,可以采用Hertz准静态理论研究次碰撞过程的一些机理和规律;(4)后续次碰撞过程明显受到了柔性梁整体变形运动的影响,反过来又影响到钢球的上抛运动和梁的后续瞬态响应,使得下一次碰撞的发生变得难以预测.The sub-impact phenomenon of a simply supported beam struck by a steel sphere were studied by the Hertz impact theory and the three-dimensional dynamic finite element method, and tested by a set of sub-impact experimental device self-designed and its corresponding transient measurement system of the sub-impact. The sub-impact phenomenon was thoroughly discussed and studied through the experimental tests and numerical simulations. The results show that： （1） the impact duration of the first sub-impact is coinciding very well with the Hertz impact duration; （2） The subsequence sub-impacts have some different characteristics from the first sub-impact. And their impact durations vary randomly around the Hertz impact duration, but their variation in general are coincide with the Hertz impact duration; （3） It shows that the complicated sub-impacts that look like random and sensitive to structural transient response are dominated by local impact-contact deformation, and their mechanism can be explained by the Hertz impact theory; （4） The theoretical analysis has shown that the processes of the subsequence sub- impacts are influenced greatly by the global structure vibrations, in turn affecting sphere motion and beam vibration response, and eventually leading to the next collision is difficult to predict.

关 键 词：梁 次碰撞 实验 数值仿真 理论分析 碰撞时间 

分 类 号：O313.4[理学—一般力学与力学基础]