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为了揭示轮轨波状表面与非稳态载荷的内在联系,利用有限元法,建立了二维弹塑性轮轨纯滚动接触计算模型,分析法向接触载荷波动值对钢轨残余应力、应变和变形的影响。模型中材料本构采用考虑棘轮效应的Jiang-Sehitoglu模型,非稳态仅考虑法向接触载荷的简谐变化,用弹塑性无限半空间表面上重复移动赫兹法向压力分布模拟反复纯滚动接触过程。发现非稳态法向接触载荷作用下产生同样波长的波状接触表面;随滚动次数的增加,残余应力增大,但很快趋于稳定,而残余应变也增大,但增大速率衰减;载荷波动值越大,波谷和波峰处的纵向残余应力越大,波谷处的轴向残余应力、残余剪应变和表面纵向位移越大,而波峰处的轴向残余应力、残余剪应变和表面纵向位移越小,波深越大。
In order to reveal the inherent relationship between wheel-rail wavy surface and unsteady load, a two-dimensional elastic-plastic wheel-rail pure rolling contact model was established by finite element method. The influence of normal contact load fluctuation on the residual stress, strain and deformation of the rail influences. In this model, the Jiang-Sehitoglu model considering the ratchet effect is used. In the unsteady state, only simple harmonic changes of the normal contact load are considered, and the Hertz normal pressure distribution on the surface is repeatedly simulated in the infinite half-space to simulate the repeated pure rolling contact process . It is found that the wavy contact surface with the same wavelength is produced by the unsteady normal contact load. The residual stress increases with the increase of the rolling number, but tends to be stable quickly and the residual strain increases, but the rate of increase decays. The load The larger the fluctuation is, the larger the longitudinal residual stress is at the troughs and crests, the greater the axial residual stress, the residual shear strain and the longitudinal longitudinal displacement of the trough are, while the axial residual stress, residual shear strain and surface longitudinal displacement The smaller, the greater the wave depth.