摘要
为探究共振碎石机在路面改造过程中的动力学行为,研究外部参数对其振动的影响,用以对实际工程应用提出帮助,首先基于共振碎石机的力学原理,对其进行合理的力学模型简化,建立了共振碎石机共振大梁的动力学模型。考虑刚体振动,求解了系统作刚体振动的固有频率及模态。基于假设模态法,将刚体振动模态和自由梁的弹性振动模态取为假设模态,对系统进行了离散,分析了系统的固有频率,得到了强迫振动响应的解析解。然后着重研究了系统参数(包括共振大梁截面尺寸、减震器等效刚度、锤头质量、激振器质量等)对共振频率的影响,分析了阻尼参数对锤头端响应的影响。结果表明:系统做刚体振动时的固有频率分别为3.35,5.87 Hz,不在共振碎石机的工作频率范围内,工作频率发生在弹性振动阶段;改变系统参数会引起结构共振频率的增大或减小,其中激振端与锤头端质量对共振频率的影响呈反比;共振大梁截面的高度对共振频率的影响最大,随着截面高度的增大共振频率呈现明显的上升趋势,并且越高阶,频率受影响越大,最大增长率超过20%;外激励频率逼近系统固有频率时发生共振,锤头振幅变大,此时利用能量的效率越高且弹簧刚度越大,发生共振时的频率越高;当阻尼器的阻尼系数增大时,锤头的振幅呈现衰减的趋势。
In order to explore the dynamic behavior of the resonant stone crusher in the process of pavement reconstruction,and study the influence of external parameters on its vibration,wish used to help practical engineering applications,first,based on the mechanics principle of the resonance stone crusher,a reasonable mechanical model was simplified,and the dynamic model of the resonance beam of the resonance stone crusher is established.Considering the rigid body vibration,the natural frequency and the mode of the rigid body vibration of the system are solved.Based on the hypothetical mode method,taking the rigid body vibration mode and the elastic vibration mode of the free beam as the hypothetical modes,the system is discretized and the natural frequency of the system is analyzed,and the analytical solution of the forced vibration response is obtained.Then,the influence of the system parameters(including cross-sectional size of resonant beam,equivalent stiffness of shock absorber,weight of hammerhead,mass of exciter,etc.)on the resonance frequency is studied,and the influence of damping parameters on the response of the hammer tip is analyzed.The result shows that(1)the natural frequencies of the system vibrates rigidly are 3.35 Hz and 5.87 Hz,which are not within the working frequency range of the resonant rock crusher,and the working frequencies occur in the elastic vibration stage;(2)changing the system parameters will increase or reduce the structural resonance frequency,where the influence of the weights of exciting end and the hammer tip end on the resonance frequency is inversely proportional;(3)the height of the resonant beam section has the greatest influence on the resonance frequency,the resonance frequency shows a clear upward trend with the increase of the section height,and the higher the order,the greater the influence on the frequency,the maximum growth rate exceeds 20%;(4)resonance occurs when the external excitation frequency approaches the natural frequency of the system,and the amplitude of the hammerhead becomes larger,at this time,the higher the efficiency of energy utilization and the greater the spring stiffness,the higher the frequency when resonance occurs;(5)when the damping coefficient of the damper increases,the amplitude of the hammerhead shows a tendency to attenuate.
作者
李吉祥
范晨光
李彦达
LI Ji-xiang;FAN Chen-guang;LI Yan-da(School of Mechanics and Engineering,Southwest Jiaotong University,Chengdu Sichuan 611756,China)
出处
《公路交通科技》
CAS
CSCD
北大核心
2020年第11期15-21,共7页
Journal of Highway and Transportation Research and Development
基金
国家自然科学基金项目(11302181)。
关键词
道路工程
共振
假设模态法
共振碎石机
参数控制
road engineering
resonance
hypothetical modal method
resonance stone crusher
parameter control
