钢轨短波长波浪形磨损的安定性分析

针对轮-轨滚动接触的短波长波浪形磨损现象,采用有限元法分析了三维实体模型的接触状态,通过计算分析了高频力作用下接触表面的塑性变形过程.结果表明:在一定的运动条件下,由于重复滚压作用,接触表面发生硬化并达到安定极限状态,生成有规律的短波长变形;钢轨表面塑性变形受枕木间距的影响;就具有随动硬化特性的钢轨材料而言,当摩擦系数μ<0.3时,屈服现象发生在材料表层下方;随着摩擦系数的增大,接触表面的切向力增大,安定极限的临界接触压力Po降低,屈服点移向接触表面,材料失效加快.

Shakedown Analysis of Rolling Contact Surface with Short-Wavelength Corrugation

The contact of a rail-wheel was analyzed making use of three-dimensional elasto-plastic finite element method, with respect to the short wavelength corrugation on the wheel/rail contact surface. The plastic deformation process on the contact surface of the rail in the presence of high frequency force was analyzed based on the calculating results. It was showed that the rail contact surface experienced hardening and plastic deformation in the repetitive rolling of the high frequency force under certain conditions, which led to short-wavelength strain and corrugation of the rail. The plastic deformation and shakedown limit of the rail was related to the sleeper distance and the friction coefficient, which was attributed to the kinematic hardening of the rail material. The yielding of the rail material occurred at some spot of the sub-surface when the friction coefficient was below 0.3, while it occurred on the contact surface when the friction coefficient was above 0.3, and in the latter case the rail material would fail faster than in the former case.