门式起重机小车-轨道耦合系统摩擦振动特征分析

Analysis of Friction-Induced Vibration Characteristics of Gantry Crane Trolley-Track Coupling System

本研究建立起门式起重机小车—轨道耦合模型,采用隐式动力学分析算法,研究了起重小车在轨道上滚动过程中产生的摩擦振动现象。结果表明,起重机的低阶结构模态主要表现为主梁的弯曲运动,随着阶次增大,起重机的自然模态逐渐演变为主梁—轨道—车轮三者耦合运动的形式。在摩擦力作用下,车轮与轨道之间将会产生某特定频率和特定振型的摩擦振动现象。隐式动力学分析结果表明,在小车与轨道摩擦过程中,起重小车与轨道均出现了明显的振动现象,且系统的切向振动强度大于法向振动强度,这也导致所提升物体的切向偏摆现象更加剧烈,造成更加严重的安全隐患。小车—轨道的摩擦振动具有多频复合的特征,轨道的振动主要表现为高频振动,而小车的振动是高频和低频的结合。起重小车在轨道上滚动的过程中,由于摩擦振动的存在,车轮与轨道的接触状态发生实时改变,从而使得最大应力位置发生变形。本研究结果对认识起重机的稳定性具有一定的意义,并能为改善起重机摩擦振动问题的结构设计提供参考。

The coupling model of gantry crane trolley and track is established,and the friction-induced vibration of gantry crane trolley during rolling on track is studied by using implicit dynamic analysis algorithm.Results show that the structure mode of the crane with lower order is main⁃ly represented by the bending motion of the main beam.With the increase of the order,the natural mode of the crane gradually evolves into the form of coupling motion of girder,track and wheel.With the action of friction,there will be a certain frequency and a certain mode of friction vibra⁃tion generated from the wheel and the track.Implicit dynamics analysis results show that during the sliding process,both trolley and track exhibit obvious vibration phenomenon,and the tangential vibration intensity is greater than the normal vibration intensity,leading to improve the cutting of the deflection of the phenomenon is more intense,causing more serious security hidden danger.The friction-induced vibration of trolley-track has the characteristic of multi-frequency composite,the vibration of the track is mainly manifested as high frequency vibration,while the vibration of trolley is the combination of high frequency and low frequency.During the friction process of the lifting trolley on the track,the contact state be⁃tween the wheel and the track changes in real time due to the existence of frictional vibration,which results in the deformation of the maximum stress position.The results of this study have a certain meaning to understand the stability of the crane,and can provide a reference for improving the structure design of the crane’s friction vibration problem.