摘要
建立了一类简谐激励作用下、两自由度含干摩擦无足自驱动系统的力学模型,描述并分析了系统的运动特性,得到了系统参数选择的最佳范围。研究发现:在低频区,随着激励频率ω的减小,擦边分岔诱导系统碰撞次数逐渐增加,直至颤振序列;在高频区,系统存在混沌运动。在一个完整周期内,基体的运动由黏滞、正向驱进和负向驱进三种中的一种或多种组成;系统平均驱进速度v对激励频率ω和质量比μm的变化较敏感,摩擦比f、间隙δ、刚度比μk对系统的影响相对较小,质量比μm的最佳选择范围为[0.4,0.8];系统正向和负向驱进的最大平均速度出现在低频区和质量比较小时;在高频区,基体趋于黏滞状态。该研究结果和方法,可为无足自驱动系统的设计及参数优化提供相应的理论依据。
The mechanical model for a two degrees of freedom self-driving system with dry friction subjected to simple harmonic excitation was established. The motion characteristics of the system were described and analyzed, and the optimal selection range of system parameters was obtained. It is found that in the low frequency region, with the decrease of the excitation frequency ω, the number of impacts induced by the grazing bifurcation gradually increases until to a chatter sequence. In the high frequency region, the chaotic motion can be observed. In a complete cycle, the motion of the substrate consists of one or more of three types motions: sticking motion, forward driving motion, and negative driving motion. The average driving speed of the system v is sensitive to changes in excitation frequency ω and mass ratio μm. The friction ratio f, clearance δ and stiffness ratio μk have relatively weak influence on the system, and the best choice range of mass ratio is [0.4,0.8]. The maximum average speed of the forward and negative driving of the system occurs in the low frequency region and with a small mass ratio. In the high frequency region, the substrate tends to make sticking motion. The results and methods in the paper provide some theoretical basis for the design and parameter optimization of wheel-free self-driving systems.
作者
李国芳
俞力洋
丁旺才
吴少培
LI Guofang;YU Liyang;DING Wangcai;WU Shaopei(School of Mechatronic Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)
出处
《振动与冲击》
EI
CSCD
北大核心
2020年第14期9-16,共8页
Journal of Vibration and Shock
基金
国家自然科学基金(11962013,11732014)
兰州交通大学-天津大学联合创新基金(2019059)。
关键词
干摩擦
无足自驱动系统
驱进速度
擦边分岔
颤振
dry friction
wheel-free self-driving system
driving speed
grazing bifurcation
chatter
