磨耗车轮作用下心轨廓形参数合理匹配研究OA

Wheel-rail profile matching significantly affects the dynamic performance of wheel-rail inter-action in fixed crossings.Changes in wheel and rail profiles during service intensify wheel-rail dynamic impacts and impair train running performance.To clarify the effects of wheel-tread wear and changes in the nose-rail profile on wheel-rail dynamic characteristics in the crossing area,this study investi-gates the nose-rail profile parameters under worn wheel conditions.First,a dynamic evaluation method that accounts for parametric reconstruction of the nose-rail profile is developed based on Non-Uniform Rational B-Splines(NURBS)and vehicle-track coupled dynamics.The wheel-rail dynamic character-istics of a train passing through crossings with different nose-rail profile parameters are then investi-gated for both standard and worn wheel treads.The relative effects of the wheel and nose-rail profiles are quantified,and the effects of the railhead slope and proportional coefficient on the dynamic re-sponses are determined.Finally,appropriate nose-rail profile parameters are selected by comparing the dynamic responses of all parameter sets.The results show that,for a standard wheel tread,the nose-rail profile parameters significantly affect the wheel-rail interaction forces but have little effect on safety and ride-quality indices.For worn wheel treads,the railhead slope has a greater effect on the peak vertical and lateral wheel-rail forces than the proportional coefficient.Changes in the wheel-tread profile exert greater effects on the wheel-rail interaction forces,derailment coefficient,and wheel-load reduction rate than the nose-rail profile parameters,whereas both factors have little effect on the verti-cal and lateral carbody accelerations.A railhead slope of 1/20 combined with a proportional coefficient of 1/3 produces the fewest positive deviations in the maximum vertical and lateral wheel-rail forces across the operating stages;this combination is therefore selected as the nose-rail profile suitable for worn wheel treads.These findings provide a reference for the structural design and optimization of crossing areas and may further improve the dynamic performance of trains passing through crossings.