轮对扁疤动态冲击激励对车辆垂向振动特性的影响

Influence of Wheel Flat Scar Dynamic Impact on Vertical Vibration Characteristics of the Vehicles

在轨道车辆高速运行过程中,由于紧急制动或者轮对打滑空转等原因造成的踏面局部擦伤和剥离统称为轮对扁疤。基于计算多体动力学和轮轨接触理论,建立了考虑扁疤冲击的动车组动力学模型,模拟车辆的动态响应特性。在该模型的基础上研究了高速列车轮对新旧扁疤以及几何尺寸对车辆系统动态行为的影响,给出不同速度下车体、构架、轴箱垂向振动等振动状况,确定高速行车条件下轮对扁疤对动力学性能的影响。结果表明:轮对扁疤对高速动车组轮轨接触及轴箱垂向激扰有着极大的影响,在轮对扁疤作用下,轮轨冲击和轴箱振动情况比正常轮对情况要严重得多;另一方面由于一系钢簧和二系空气弹簧低频滤波作用的存在,削弱了扁疤振动激扰对构架和车体的影响。

In the process of high-speed operation of railway vehicles,the local tread scratches and stripping caused by emergency braking or wheel pair skidding and idling are collectively referred to as wheel flat scar.Based on computational multi-body dynamics and wheel-rail contact theory,a dynamic model of EMUs considering flat scar impact was established to simulate the dynamic response characteristics of vehicles.On the basis of this model,the influence of old and new flat scar and geometric dimensions wheel pairs on the dynamic behavior of vehicle system was studied.The vibration status of vehicle body,frame and axle box at different speeds was given,and the influence of wheel flat scar on dynamic performance under high-speed driving conditions was determined.The results showed that wheel flat scar has a great influence on wheel-rail contact and axle box vertical excitation of high-speed EMUs.Under the action of wheel flat scar,wheel rail impact and axle box vibration are much more serious than that of normal wheel rail;on the other hand,due to the existence of low-frequency filtering function of primary spring and secondary air spring,the influence of wheel flat scar vibration excitation on frame and body is weakened.