基于橡胶弹簧非线性模型的重载车辆轮轨动力特征分析

Wheel-rail Dynamic Interaction between Heavy-haul Freight Car and Ballasted Track Based on A Nonlinear Rubber Spring Model

针对重载车辆一系悬挂橡胶弹性元件,采用分数阶导数理论建立具有历史依赖性的橡胶弹簧非线性力学模型,并将该模型应用于重载车辆-轨道耦合动力分析系统中,比较了传统的Kelvin-Voigt线性模型与该非线性模型在车轮扁疤冲击荷载与实测轨道随机不平顺作用下轮轨动力响应的差异。计算结果表明：在车轮扁疤冲击荷载条件下,传统线性模型与非线性模型得到的轮轨垂向力在低于200Hz频率范围内存在明显的差异,采用线性模型会低估10-80Hz频率范围内的轮轨垂向力,且会高估80~200Hz频率范围内的轮轨垂向力;在轨道随机不平顺作用下,非线性模型得到的轮轨垂向力变化范围更大,且侧架加速度与车体加速度较线性模型均有所下降。

A nonlinear mechanical model for the rubber springs in heavy-haul vehicles was built based on the fractional derivative theory,in which history dependence for the nonlinear rubber springs can be accurately described.The model was used in the heavy-haul freight wagon-track coupled dynamic analysis system to compare the difference of the wheel-rail dynamic response of the nonlinear model and the traditional Kelvin-Voigt linear model of the rubber spring under the impulse load of the wheel flat and track random irregularity.Results indicated that under the impluse load of the wheel,a significant difference was found in the wheel-rail vertical force in the frequency range below 200 Hz between the two models.The wheel-rail vertical force in the linear model was underestimated in the frequency range of 10-80 Hz and overestimated in the frequency range of 80-200Hz.In addition,with the existence of track random irregularity,the variation range of the wheel-rail vertical force was larger in the nonlinear model.The accelerations of side frames and car body decreased in the nonlinear model compared with the linear model.