路基冻胀作用下车辆的动力响应变化规律

Dynamic Response Changes of Vehicles under the Action of Roadbed Frost Heave

路基冻胀作用下无砟轨道产生不平顺和损害失稳,导致运行车辆产生消极的动力响应,严重影响列车的平稳运行。基于路基冻胀数值分析模型研究路基冻胀作用下车辆动力响应的影响,研究结果表明:(1)轮轨最大垂向作用力随冻胀量的增大而指数增大,车体垂向振动加速度也逐渐增大,车体垂向稳定性指标由1.70指数增大至2.56;(2)随着冻胀波长增加,车辆轮轨的最大垂向作用力、车体垂向振动加速度和车体垂向稳定性指标均逐渐降低;(3)冻胀波数对轮轨垂向作用力不产生影响,车体垂向加速度先增加后保持不变,车体垂向稳定性指标随冻胀波数增加而指数关系增大。

Under the effect of roadbed frost heave,ballastless tracks produce unevenness and damage instability,leading to negative dynamic response of running vehicles and seriously affecting the smooth operation of trains.Based on the numerical analysis model of roadbed frost heave,the influence of vehicle dynamic response under roadbed frost heave is studied.Based on the numerical analysis model of subgrade frost heave,the effect of vehicle dynamic response on subgrade frost heave is studied.The results show that:(1)The maximum vertical force of wheel-rail increases exponentially with the increase of frost heave,the vertical vibration acceleration of vehicle body also increases gradually,and the vertical stability index of vehicle body increases from 1.70 index to 2.56 index;(2)With the increase of frost heave wavelength,the maximum vertical force of wheel and rail,the vertical vibration acceleration of vehicle body and the vertical stability index of vehicle body gradually decrease;(3)Frost heave wave number has no effect on the vertical force of wheel and rail,the vertical acceleration of car body increases first and then remains unchanged,and the vertical stability index of car body increases exponentially with the increase of frost heave wave number.