基于格林函数法的车辆—轨道垂向耦合系统随机振动分析

Analysis on Random Vibration of Vehicle-Track Vertical Coupling System with Green Function Method

视钢轨为弹性欧拉梁（Euler梁）,建立离散支撑弹性轨道模型,并采用格林函数法得到全频域范围内轨道上任意点处的频率响应;结合高速车辆模型,视车辆和轨道系统为线性弹簧阻尼系统,轮轨接触为线性刚性接触,采用基于虚拟激励法的轮轨接触多点激励,以真实轨道谱为输入,计算车辆—轨道垂向耦合系统的随机振动响应,并分析不同高速轨道谱和车速对车辆—轨道垂向耦合系统随机振动的影响。结果表明：采用格林函数法可快速求解无限长离散支撑弹性轨道模型的频响特性;分析振动频率在15 Hz以上的车体及构架振动时,采用离散支撑弹性轨道模型较传统的刚性轨道模型更为准确;计算车辆—轨道垂向耦合系统的振动能量时,在15-60Hz的中频区域内,采用离散支撑弹性轨道模型得到的计算结果要高于传统的刚性轨道模型,而在高频区域内则相反;车辆—轨道垂向耦合系统的随机振动响应对轨道谱类型和车速均较为敏感。

The rail was regarded as the elastic Euler-Bernoulli beam（Euler beam）and the discrete elastic support track model was established.Green function method was applied for calculating the frequency response at any point of the track in the whole frequency domain.Combined with high speed vehicle model,the vehicle-track system was considered as the linear spring-damping system and wheel-rail contact was considered as linear rigid contact.With real track spectrum as input,the random vibration of vehicletrack vertical coupling system was calculated with the multipoint excitation of wheel-rail contact based on pseudo excitation method.Moreover,the influence of different high speed track spectrum and train speed on the random vibration of vehicle-track vertical coupling system was analyzed.The results show that Green function method can rapidly get the frequency response characteristics for infinite discrete elastic support track model.Compared with the traditional rigid track model,the discrete elastic support track model can more accurately analyze the vibration of car body and framework at the vibration frequency of above 15 Hz.In calculating the vibration energy of vehicle-track vertical coupling system at the intermediate frequency range of 15~60Hz,the results calculated by discrete elastic support track model are higher than those obtained by traditional rigid track model,but the results are the opposite at high frequency range.The random vibration response of vehicle-track vertical coupling system is more sensitive to both the types of track spectrum and train speed.