基于一重载铁路曲线段的线路条件与钢轨焊缝不平顺现场测试数据,通过建立30 t轴重重载货车-轨道耦合动力学模型,分析了重载铁路钢轨焊缝不平顺参数与曲线参数对重载轮轨系统动力响应的影响规律.结合轮轨动力性能安全评价指标,分析了不同类型重载线路钢轨焊缝短波不平顺的安全限值.结果表明:在小半径曲线段,钢轨焊缝不平顺对重载行车安全性威胁更大;轮重减载率和轮轨垂向力响应指标受钢轨焊缝不平顺的影响较大,可作为钢轨焊缝不平顺动力影响研究的敏感指标;曲线段钢轨焊缝不平顺短波波深限值随行车速度增加而减小,随曲线半径减小而略有减小;30 t轴重重载货车以100 km/h运行于半径400 m的曲线线路时,凸形焊缝不平顺的短波波深安全限值为0.2 mm,凹形焊缝不平顺的短波波深安全限值为0.1 mm.
Safety Management Limits for Rail Weld Irregularity in Small Radius Curved Sections of Heavy Haul Railway
Based on the line conditions of a curved section of a heavy haul railway and on-site test data of rail weld irregularities,a coupled dynamic model of a 30 t axle load heavy haul freight-track was established to analyze the influence law of rail weld irregularities and curve parameters on the dynamic response of the heavy haul wheel-rail system.Combining the safety evaluation indicators of wheel-rail dynamic performance,the safety limit values of short-wavelength irregularity of rail welds on different types of heavy haul lines were analyzed.The results show that in small radius curved sections,rail weld irregularity pose a greater threat to the safety of heavy haul driving.The wheel unloading rate and the response index of wheel-rail vertical force are greatly affected by the rail weld irregularity,and can be used as sensitive indicators for studying the dynamic impact of rail weld irregularity.The limit value of short-wavelength irregularity in curved steel rails decreases with increasing driving speed and slightly decreases with decreasing curve radius.When a 30 t axle heavy haul freight runs on a curved line with a radius of 400 m at a speed of 100 km/h,the safety limit value of the short-wavelength irregularity for convex weld depth is 0.2 mm,and the safety limit value of the short-wavelength irregularity for the concave weld is 0.1 mm.
heavy haul railwayrail weld irregularitynumerical simulationwheel-rail responsesafety limitssmall radius curve
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