振动压路机用于不同土壤地面的平顺性评价

实际工况中振动压路机车轮会在各种土壤地面上作业和行驶,为了评价振动式压路机在不同土壤路面上的行驶平顺性,该文针对车轮―不同土壤地面的接触分析,建立了某单钢轮振动压路机非线性动力学模型;描述了振动轮在弹塑性土壤下压实对前车架产生垂直激励力.基于Adam D和Kopf F的弹塑性土壤模型,建立了振动轮在作业时的三自由度振动模型;采用软性土壤地面的Bekker假设,建立了轮胎―变形土壤地面接触模型.对建立的非线性动力学模型进行了仿真,并根据ISO2631-1:1997(E)标准分析与评价了不同路况、工况和速度对驾驶员乘坐舒适性的影响.结果表明,刚性路面不平度等级对振动压路机行驶平顺性有较大影响,路面等级越差,驾驶员的主观感觉越不舒适;路面的变形对驾驶室水平晃动有较大影响,土壤路面越软,驾驶室晃动越大;弹塑性土壤对振动压路机的影响表现在低频工况压实时,车辆平顺性比较差.该研究可为振动式压路机的平顺性设计提供参考.

Ride comfort evaluation of vibratory roller under different soil ground

In realistic working conditions, a vibratory roller operates and moves on various kinds of soil ground and when it does vibration excitation sources, such as soil ground, drum and engine are transmitted to the driver through the isolation systems of the cab and seat, which has direct influence on the driver's health and their working efficiency. Thus, in order to evaluate the riding comfort of a vibratory roller under the different soil grounds, a nonlinear dynamics model of a single drum vibratory roller was established in this paper, based on the analysis of the contact physics of the wheel with different soil grounds. In order to describe the vertical excitation force acting on the front frame generated by a vibratory drum with elastic-plastic soil, a 3-DOF vibration model which describes vibratory drum operating is developed in this study, based on Adam D. and Kopf F's elastic-plastic soil model. Using Bekker's hypothesis of the soft soil ground, the tire- deformation soil surface contact model was established to analyze the vertical excitation force acting on the rear frame. Matlab/Simulink software was used to simulate the nonlinear dynamic models and calculate the values of the vertical weighted r.m.s acceleration responses of driver's seat and cab. The nonlinear dynamics model of the whole vehicle was analyzed according to the ISO 2631: 1997 (E) standard, the influence of noise and vibration to human health which evaluates the influence of the different road conditions, operating conditions, and vehicle speeds on the driver's ride comfort. The results showed that the rigid road surface roughness level has a greater influence on vibratory roller ride comfort that a driver subjectively feels is very uncomfortable when the vehicle moves on a poor road surface roughness. The deformation of the road surfaces dominate cab sloshing when a vehicle moves on relatively soft soil road surface. And in a low frequency region, vehicle ride comfort becomes worse when there are vibratory compacts and moves on elastic-plastic soil. The study can provide a reference for vibration roller ride comfort design.