变质量弹性梁结构动力学特性  

Dynamics charactersitics of flexible beams undergoing time varying mass

作　　者：马驰骋[1,2] 郭宗和[1] 刘灿昌[1] 代祥俊[1] 张希农[2] 毛伯永[2] MA Chicheng;GUO Zonghe;LIU Canchang;DAI Xiangjun;ZHANG Xinong;MAO Boyong(College of Transportation and Vehicles Engineering,Shandong University of Technology,Zibo 255000,Shandong,China;State Key Laboratory for Strength and Vibration of Mechanical Structures,Xi＇an Jiaotong University,Xi＇an 710049,Shaanxi,China)

机构地区：[1]山东理工大学交通与车辆工程学院,山东淄博255000 [2]西安交通大学机械结构强度与振动国家重点试验室,陕西西安710049

出　　处：《山东大学学报（工学版）》2018年第4期78-87,共10页Journal of Shandong University（Engineering Science）

基　　金：机械结构强度与振动国家重点实验室开放基金资助项目(SV2016-KF-07);山东省自然科学基金资助项目(ZR2016AL06;2016ZRB0179SF)

摘　　要：以变质量弹性梁结构为力学模型,利用模态叠加法推导系统的运动方程,分析质量变化引起的非结构阻尼对系统振动的影响,使用自适应Newmark法求解系统的振动响应。设计变质量-弹性梁结构动力学测试试验,通过控制液体的流入流出实现系统质量的变化。采用时频分析技术处理时变系统的非平稳响应信号,在时频域上更全面得到了系统的振动特性。数值仿真和试验结果一致,说明建模以及试验设计的有效性。研究表明:系统质量减小会引起一个非结构负阻尼,对系统的振动影响非常显著,在机械臂等高精度结构设计时,不能忽略该非结构阻尼对系统振动特性的影响。In terms of an elastic beam with a time varying mass,the oscillation equations were derived using mode superposition method,and the influences of the nonstructural damping induced by the changing mass were investigated. The differential equations were solved by self-adaptive Newmark method,then a relative confirmatory experiment was designed,while the change of the mass was realized by controlling the flowof water. The vibration signals were processed using time-frequency analysis toolkit,which showed more features of the time varying mass system in the time-frequency domain. The comparison of experimental results and numerical results demonstrated the feasibility of the proposed approach and the experimental test. The study showed that the nonstructural negative damping induced by the decreasing mass affected the motions significantly,which could not be neglected in the dynamic design of high precision structures as large-scale flexible robotic manipulators.

关 键 词：变质量系统 时变结构 自适应Newmark法 时频特性 试验 

分 类 号：O329[理学—一般力学与力学基础]