特定车速下长头重卡驾驶室异常振动分析

Analysis of Abnormal Vibration of Long-head Heavy Truck Cab at Specific Speed

针对某长头重卡以90 km/h的速度在良好路面行驶过程中出现的驾驶室侧围异常振动现象展开研究。在故障分析和道路试验的基础上,基于PolyLSCF参数识别法对驾驶室白车身进行模态测试,建立驾驶室白车身有限元模型。通过试验与分析相结合的方法,分析外界激励对驾驶室振动的影响,掌握长头车驾驶室的振动特性,找到驾驶室异常振动的原因。研究结果表明:该长头重卡驾驶室侧围刚度较弱,局部模态复杂,模态特性与平头车驾驶室有所不同,特定速度下车轮激励的倍频与驾驶室1阶扭转频率相近。针对驾驶室异常振动问题,提出了结构优化方案,并通过仿真验证了优化措施的有效性。

This article focuses on the phenomenon of abnormal vibrations on the side of the cab that occur when a long-headed truck is traveling at a speed of 90 km/h on a good road.On the basis of fault analysis and road test,the modal test of cab BIW is carried out based on PolyLSCF parameter identification method,and the finite element model of cab body in white is established.Through the method of combination of test and analysis,the influence of external excitation on the vibration of cab is analyzed,the vibration characteristics of cab of long head car are mastered,and the cause of the vibration problem of cab is found.The research shows that the stiffness of the side of the long-head heavy truck cab is weak and the local modes are complex.The modal characteristics are different from those of the flat-head cab,and the frequency doubling of the wheel excitation is similar to the firstorder torsional frequency of the cab at a certain speed.Aiming at the problem of abnormal vibration of the cab,a structural optimization scheme is proposed,and the effectiveness of the optimization measures is verified through simulation.