液压减振器双向比对机车动力学性能影响研究

Study the influence of hydraulic shock absorber bidirectional ratio on dynamic performance of locomotive

为研究机车悬挂系统液压减振器双向比对机车动力学性能的影响,以某六轴宽轨机车为对象,利用Simpack软件建立了主要由车体、构架和轮对三大部分构成,共计90个自由度的车辆动力学模型,其中嵌入了减振器的非线性阻尼特性。在AAR 5级轨道谱的随机激励下,分别对减振器双向比大于1、等于1和小于1的阻尼模型所对应的机车动力学性能进行仿真分析。结果表明:当一系垂向减振器双向比为1时,直线工况下的机车垂向Sperling平稳性指标为3.08,加速度功率谱密度最大为0.11 m^(2)/s^(3),均小于双向比不为1的阻尼模型,能更有效衰减传递到车体的振动;在直线工况和车速小于100 km/h的条件下,减振器双向比等于1时一系悬挂装置和二系悬挂装置的垂向动荷系数均最小,但车速大于100 km/h时却不是最小;对于减振器双向比为1的阻尼模型,曲线工况下的机车抗脱轨系数和二系悬挂装置垂向动荷系数相比双向比不为1时更优,但一系悬挂装置垂向动荷系数值却最大;当二系横向减振器双向比为1时,机车非线性临界速度最大值达到263 km/h,均高于双向比不为1时的非线性临界速度。研究可为机车悬挂系统的设计提供一定的参考。

In order to study the influence of bidirectional ratio of hydraulic shock absorber in locomotive suspension system on locomotive dynamic performance, a vehicle dynamic model with 90 degrees of freedom was established by using Simpack software, which consisted of body, frame, wheelset etc. The nonlinear damping characteristics of shock absorber were embedded. Under random excitation of AAR 5 track spectrum, the locomotive dynamic performance corresponding to the damping model with two-way ratio of shock absorber greater than, equal to and less than 1 was simulated and analyzed respectively. The results show that: When the bidirectional ratio of primary vertical shock absorbers is 1, the vertical Sperling stability index of the locomotive under linear working condition is 3.08,and the maximum acceleration power spectral density is 0.11 m^(2)/s^(3), both of which are smaller than the damping model with bidirectional ratio not 1, and the vibration transmission to the car body is more effectively attenuated. The vertical dynamic load coefficients of the primary and secondary suspension systems are minimum when the bidirectional ratio of the shock absorber is equal to 1, but they are not minimum when the vehicle speed is greater than 100 km/h. For the damping model with bidirectional ratio of 1, the anti-derailment coefficient of the locomotive and the vertical dynamic load coefficient of the secondary suspension device under curving conditions are better than that with bidirectional ratio greater than 1 or less than 1, but the vertical dynamic load coefficient of the primary suspension device is the largest. When the bidirectional ratio of the secondary transverse shock absorber is 1, the maximum nonlinear critical speed of the locomotive reaches 263 km/h, which is higher than that when the bidirectional ratio is greater than or less than 1. The research can provide some reference for the design of locomotive suspension system.