重载铁路不同磨耗阶段车轮与曲线钢轨的接触分析

Analysis of the Contact between Wheel and Rail with Different Wear Profiles in Curve on Heavy Haul Railway

应用轮轨型面测量仪在大秦重载线路上跟踪测量不同磨耗阶段的货车车轮和钢轨型面,并选取典型的轮轨型面,针对曲线轮缘贴靠位置,建立轮轨三维接触有限元模型,进行弹塑性计算分析。计算结果表明:在相同的载荷工况下,随着轮缘的磨耗,轮轨接触斑面积呈现出先增加后减小的变化趋势,初期车轮轮缘根部局部剧烈磨耗,逐渐扩大到整个轮缘剧烈磨耗,然后从III型面开始,轮缘和踏面磨耗均匀,轮缘磨耗进入相对稳定的磨耗阶段直至磨耗到限;在曲线位置处,各个磨耗阶段的车轮型面与磨耗稳定期钢轨型面相匹配时的等效应力均明显小于与标准钢轨相配合时的等效应力,而且磨耗后的钢轨型面能够显著改善轮缘贴靠时的应力分布情况,减小轮轨间等效应力,能相对减轻轮轨磨耗;综合考虑轮轨接触斑面积、等效应力的大小与分布情况,III型车轮型面的综合指标相对较优。

The freight wagon wheel profiles and rail profiles of different wear stages are tracked and measured by the wheel-rail profile admeasuring apparatus from Datong-Qinhuangdao Heavy haul line. The typical wheel-rail profiles are selected and the finite element method（FEM） models of wheel-rail contact are established when the flange gets close to the rail in the curve segment. The elastic-plastic analysis of the FEM models is presented. The results show that under the same loading condition, with the abrasion of wheel flanges, the wheel-rail contact areas increase at first and then decrease. The root of wheel flange is worn severely at preliminary stage, and the wear gradually extends to the entire wheel flange. Starting with the wheel profile III, wheel flange and tread are worn evenly. The wheel flange wear gets into the relatively stable stage until the abrasion limit. When contacting with different stages of wheel profiles in curve, the equivalent stresses of the stable stage of worn rails are obviously smaller than that of the standard rails. Furthermore, the stable stage of worn rails could significantly improve the stress distribution when the flange gets close to the rail in the curve segment, and the wheel-rail contact stresses decrease, which can relatively reduce the abrasion of wheel and rail. Taking all the factors above into consideration, such as the wheel-rail contact area, contact stress and its distribution, the composite indicator of wheel profile III is relatively better.