轴箱对轨道不平顺的响应及其可测性分析

轨道不平顺会加剧轮轨的动态作用,引起轮轨部件损坏、噪声等问题,一直是铁路维护工作的重点。考虑到维护的成本,对轨道不平顺程度的实时监测显得尤为重要,其中轴箱加速度信号的二次积分是使用较多的方法。然而轴箱加速度包含的成分复杂,为了更深入地认识轴箱加速度的测量结果,建立多车轮与轨道相互作用模型,详细分析轨道不平顺激励下的轴箱与转向架的动态位移响应,重点关注轴箱响应对轨道不平顺的可测性,并给出了扩大测量频率范围的建议。结果显示:低频(长波长)情况下轴箱对轨道不平顺的响应接近理想,但是高频的位移响应受到多车轮耦合作用的影响,呈现很大的不确定性。

Dynamic Response of Axle-boxes to Rail Unevenness Excitation due to Multiple Wheel-rail Interactions andIts Measurability Analysis

Track irregularities give rise to severe wheel/rail interaction and thus the fatigue of vehicle and rail parts and railway noise, which make it a key point of track maintenance. Considering the costs of maintenance work, real-time monitoring of track unevenness becomes very important. The most frequently-used method of track condition monitoring is to double integrating the axle-box acceleration. But axle-box response is found to be influenced by various factors. To obtain a better understanding of measurement results, the dynamic behavior of axle-box response to the unevenness excitation due to multiple wheel/rail interactions is analyzed in frequency domain with “moving irregularity” model considered. Based on the analysis of axle-box response, the measurability of track unevenness is discussed. Results show that the response of axle-box to track unevenness at long wavelength is nearly ideal whereas at higher frequencies it is influenced by the standing waves formed between wheels and presents a variety of uncertainty due to wave reflections. In order to extend the range of measurable wavelength, it is suggested that the unevenness measurability via axle-box acceleration can be improved by reducing the mass of measuring wheel.