重载铁路钢轨隐伤病害处振动特性分析EI北大核心CSCD

钢轨隐伤病害在重载铁路中大量存在,病害发展后期会导致病害位置整个轨道-路基动态响应增大,严重影响轨道-路基正常服役状态。为研究重载铁路典型隐伤病害产生后对整个轨道-路基的时频域影响特征,开展了现场静态测试与病害原因分析,以及分别进行了病害断面和正常断面的动态行车测试对比试验,得出了病害断面的时频域及振动传递特征。结果表明:病害断面钢轨轨头存在局部低塌、剥离掉块及多裂纹病害,轨头表面会存在明显的裂纹扩展区,其呈Y型扩展并有贯通整个轨头的趋势。病害断面轨道-路基振动明显较正常断面大,其中钢轨、轨枕、道床及路基振动大小均值分别是正常断面的26倍、23倍、13倍及5倍;病害断面轨道-路基频谱峰值存在转向架和邻轴距为基频10 Hz左右的周期性调制频率;病害断面轨枕下道砟粉化严重导致振动能量在2000 Hz附近几乎无衰减,而正常断面在2000 Hz附近由上至下各层之间振动能量依次减小;车速增大对病害断面钢轨振动冲击影响最强烈,对其下部轨枕及路基影响在45~75 km/h内逐渐减弱。

Vibration characteristics analysis of rail squats in heavy haul railway

Rail squats are widely exist in heavy-haul railways,resulting in an increase in the dynamic response of the entire track-subgrade at the diseased location,which seriously affects the normal service status of the track-subgrade.In order to study the characteristics of the time-frequency domain effects of typical rail squats on the entire track-subgrade in heavy-haul railways,on-site static testing and cause of disease analysis were carried out,and the dynamic test comparison between the diseased section and the normal section was carried out.Experiments have obtained the time-frequency domain and vibration transmission characteristics of the diseased section.The results show that:the rail head of the diseased section has local collapse,shelling and multiple cracks.There will exist obvious crack propagation area on the surface of the rail head,which extend in a Y-shape and have a tendency to penetrate the entire rail head.The track-subgrade vibration of the diseased section is obviously larger than the normal section,and the average value of the vibration of the rail,sleeper,ballast and subgrade is 26,23,13 and 5 times than the normal section respectively.The track-subgrade spectrum peak of the diseased section has a periodic modulation frequency with the bogie and the adjacent wheelbase at a fundamental frequency of about 10 Hz.The serious pulverization of ballast under the sleeper on the damaged section results in almost no attenuation of vibration energy near 2000 Hz,while the vibration energy of the normal section decreases sequentially from top to bottom around 2000 Hz.The increase of vehicle speed has the strongest impact on the vibration and impact of the diseased section rail,and the impact on the lower sleepers and subgrade gradually weakens in the interval of 45-75 km/h.