梁缝冲击对悬挂式单轨车桥系统动力特性的影响研究

Research on the Influences of Beam Joint Impact on the Dynamic Features of Suspended Monorail Vehicle-Bridge System

悬挂式单轨轨道梁梁端客观存在局部梁缝不平顺,列车通过时会产生较大的轮轨动力冲击,对车辆和桥梁的动力学性能均有重要影响。为探明梁缝冲击对悬挂式单轨车辆与轨道梁桥系统动力特性的影响,基于车辆-桥梁动力相互作用理论,建立悬挂式单轨车-桥耦合动力学模型,在此基础上以实测梁缝不平顺作为外部激励,研究梁缝冲击作用下车桥系统耦合振动特性及车辆系统关键参数的影响。研究结果表明:梁缝冲击会显著增大悬挂式单轨车桥系统动力响应幅值,其中车体、构架及轮轨力的响应在5 Hz以上增长显著,轨道梁振动加剧主要集中在40 Hz以上;随着梁缝不平顺幅值增大,系统垂向振动响应均呈现非线性规律增加,尤其是驱动轮轮轨力,为保障驱动轮使用安全,建议梁缝不平顺幅值不超过6 mm;为有效控制梁缝冲击对系统动力性能的影响,车辆二系悬挂垂向刚度、阻尼及驱动轮径向刚度的合理取值分别为0.1 MN/m、16 kN·s/m和4 MN/m。

Beam joint irregularities exist at the ends of suspended monorail track beams.They can cause significant wheel-track dynamic impacts when the train passes through the bridge.These impacts have a considerable influence on the dynamic performance of both the vehicle and the bridge.To reveal the effect of beam joint impacts on the dynamic features of the suspended monorail vehicle and bridge system(SMVBS),a coupled dynamic model of SMVBS was established based on the vehicle-bridge dynamic interaction theory.Using measured beam joint irregularities as the external excitation,the study explored the coupled vibration characteristics of SMVBS under the beam joint impacts and analyzed the effect of key parameters in the vehicle system.The results showed that the beam joint impacts significantly increased the dynamic response amplitudes in the SMVBS.The responses of the car body,the vehicle frame,and the wheel-rail forces showed a notable increase above 5 Hz,while the intensified vibration of the track was mainly concentrated at above 40 Hz.As the amplitude of beam joint irregularities increased,the vertical vibration response of SMVBS showed a nonlinear increase,especially in the wheel-rail force of the driving wheel.To ensure the safety of the driving wheel,it was recommended that the amplitude of beam joint irregularities should not exceed 6 mm.To effectively control the influence of beam joint irregularities on the dynamic performance of SMVBS,reasonable values for vertical stiffness and damping of the secondary suspension,as well as the radial stiffness of the driving wheel,should be 0.1 MN/m,16 kN·s/m and 4 MN/m,respectively.