共查询到20条相似文献,搜索用时 62 毫秒
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基于非Hertz滚动接触理论利用数值计算方法详细分析了静态接触情况下,横移量和摇头角对轮轨接触质点间蠕滑力、接触斑粘滑区的分布、等效应力的影响.通过数值计算表明:横移量、摇头角的变化对轮轨滚动接触行为的影响是同时存在并且相互影响的.随着横移量的增加,接触斑的滑动区逐渐增大,粘着区面积逐渐减小,横向移动分量逐渐增大,最大应力值逐渐减小;随着摇头角的增大,接触斑上滑移区面积和最大剪应力和等效应力值均逐渐增大,直至接触斑处于全滑动状态,当轮轨接触斑上的切向力达到饱和时,摇头角对接轮轨接触斑上的蠕滑力、粘滑区分布和应力分布没有影响,计算结果对研究轮轨滚动接触疲劳提供一定的参考价值. 相似文献
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接触角和横向载荷对轮轨粘着的影响 总被引:1,自引:0,他引:1
应用多层多支子结构技术建立轮对与轨道的多体接触模型,采用参变量变分原理和数学二次规划法求解轮轨接触力,根据不同的接触角和横向载荷计算得出轮轨接触力分布,分析接触角和横向载荷对纵向摩擦力(牵引力)以及粘着系数的影响。计算结果表明,轮对承受横向载荷时,轮轨接触点对之间摩擦力的方向在粘着区和蠕滑区有明显的不同,在粘着区其方向与钢轨纵向夹角较小,而在蠕滑区其方向与钢轨纵向夹角较大;当接触角较小时,粘着系数随着横向载荷的增加而减小;当接触角较大时,随着横向载荷的增加,粘着系数先增加后减小;在直线段粘着系数随着轮对承受横向载荷的增加而减小,在曲线段选取适当的横向载荷能够提高粘着系数。 相似文献
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不同介质作用下轮轨粘着特性研究 总被引:2,自引:0,他引:2
利用MMS-2A型微机控制摩擦磨损试验机开展介质工况下的轮轨粘着特性试验,研究干态、水、油、砂、树叶等介质对轮轨粘着系数的影响。结果表明:不同介质工况下的轮轨粘着系数明显不同,干态下轮轨粘着系数最大,油水介质下粘着系数最小,加水和油将显著降低轮轨粘着系数,且油介质下的轮轨粘着系数明显小于水介质下的粘着系数;随环境湿度增加轮轨粘着系数明显降低,当湿度从20%增加到100%时,粘着系数将降低约17%;干态和油水介质下,随轴重增加轮轨粘着系数呈明显增加趋势;轮轨接触面间加入新鲜树叶后粘着系数将降低,树叶与水共同作用下的轮轨粘着系数最小;通过撒砂能提高水油介质工况下的轮轨粘着系数,但会加剧轮轨试样表面损伤,导致剥落损伤出现。 相似文献
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撒砂对轮轨粘着特性的影响 总被引:4,自引:0,他引:4
利用JD-1轮轨模拟试验机研究干态/水介质工况下撒砂对轮轨粘着特性的影响,分析砂粒尺寸、撒砂量对轮轨粘着系数的影响.结果表明:干态工况下加水会使轮轨粘着系数大幅下降,撒砂可提高轮轨粘着力;水介质工况下撒细砂可使轮轨粘着系数增加50%左右,水介质工况下撒粗砂可使轮轨粘着系数增加65%左右;干态工况下撒砂对轮轨粘着系数有较小影响;水介质下撒砂的增粘效果主要取决于砂子颗粒的直径及撒砂量,大砂粒直径的增粘效果更佳,当撒砂量小于50 g/min时,随撒砂量的增加轮轨粘着系数呈增加趋势,但是撒砂量超过50 g/min时产生轮轨粘着系数小于撒砂量为50 g/min时产生的轮轨粘着系数. 相似文献
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轮轨接触的力学特性研究对保障列车的安全运行至关重要。选择动车组车轮LMa踏面与标准CHN60钢轨,借助有限元理论,分别计算两种轮径在不同轴重以及不同横移量下的轮轨接触应力变化情况。计算结果表明:随着轴重的增加,轮轨接触应力会增大;当车轮有横移时,发现靠近轮缘侧的轮轨接触应力大于远离轮缘侧的;同种工况下,增大轮径可以适当改善轮轨受力状态。 相似文献
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从研究影响轮轨滚动接触几何关系的机制出发,利用数值计算方法分析横移量和摇头角变化速率对轮轨接触质点间蠕滑力/率、接触斑黏滑区的分布等的影响。分析结果表明:横移量、摇头角的变化速率对轮轨滚动接触蠕滑特性具有重要的影响具有重要的影响;随着横移量变化速率的增加,轮轨接触斑间的横向蠕滑力/率、蠕滑力密度等增大,同时滑动区逐渐增大,黏着区面积逐渐减小,因此当列车在加速过程中要适当考虑增黏措施;随着摇头角的变化速率的增大,轮轨接触斑间的纵向蠕滑力/率、蠕滑力密度等增大,而横向蠕滑力/率、蠕滑力密度等减小,接触斑上滑移区面积逐渐增大,直至接触斑切向力达到饱和处于全滑动状态。 相似文献
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轮轨粗糙度是影响轮轨声源进而影响车内噪声的关键因素。本文基于结构有限元、声学边界元和轮轨接触力模型建立了轮轨滚动噪声预测模型,分析了120 km/h运行速度下不同轮轨粗糙度对轮轨噪声的影响。得出如下结论:120 km/h轮轨噪声主要能量集中在中高频段,且在800 Hz频段处有峰值。与车轮镟修前相比,车轮镟修后轮轨噪声总值为107.8 dB(A),降低12.1 dB(A)。车轮粗糙度主要影响轮轨噪声中高频段。不同等级钢轨粗糙度对应的轮轨噪声在106.9~117.9 dB(A)之间,且钢轨粗糙度对轮轨噪声全频段均有影响,对低频影响相对较大。 相似文献
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The article deals briefly with the principles of the method of analyzing dimensionalities and its relation to the modeling theory. It is shown that the method of analyzing dimensionalities is applicable to constructing qualitative models of wear and adhesion in the wheel-rail interface. 相似文献
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The application of an ultrasonic technique to estimate the Real Contact Area (RCA) in a wheel-rail system is proposed. The method is based on the analysis of the reflection of ultrasonic waves which are sent over the contact region and reflected by it according to the state of contact. The interaction of the experimental data with a theoretical model formulated in the early 1990s by Krolikowski allows us to calculate the RCA for the area illuminated by the ultrasonic beam. By varying the external load and the surface conditions of the contacting elements, it is possible to obtain the trend of the RCA with increasing load (for a certain roughness) as well to explore changes in RCA for different roughness while the load is kept fixed. Results showed that RCA grows almost linearly with the applied load and that an increase of one order of magnitude in combined roughness of the wheel-rail system leads to a roughly sevenfold reduction in RCA under a given load. 相似文献
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《Wear》1986,113(1):103-122
The interactions between the tribological stress parameters and the measurable wear quantities during rolling with slip are examined with the help of experimental results already published and the results of some new investigations by the authors of this paper.It is from these that the following model for wear behaviour is derived.
- 1.(1) The wear quantities (wear volume and mass loss due to wear) are first of all proportional to the frictional work.
- 2.(2) The factor of proportionality between frictional work and wear volume depends on (a) the structure of the tribological system (material pairing and environment) and (b) the temperature of the contacting surfaces. This temperature is a function of the stress collective, the influence of which may be approximated as the relation of frictional power to contact area, the surface temperature thus governing the transitions between mild and severe wear.
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《Wear》1986,113(1):123-130
Experimental investigations into the interactions between surface pressure, tangential tractions and plastic deformations during rolling gave the following results.
- 1.(1) The most intensive plastic deformations are caused by lateral frictional forces, followed by longitudinal frictional forces. The material flow is smallest with pure rolling.
- 2.(2) In agreement with Johnson's theory for a steel with a carbon content of 0.6% (similar to those used for wheels and rails) the shakedown limit was found at a maximum hertzian surface pressure of about 1600 N mm−2.
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针对天线轮轨系统中的轮轨接触变形问题,对轮轨组合的数学模型、接触关系、工作模式、运行轨道等方面进行了研究,基于多体动力学对天线轮轨系统建立了刚柔耦合模型,利用Recurdyn软件对轮轨系统进行了仿真分析,得到了轨道应力和变形云图,提出了轮轨接触模型的最大应力和最大变形出现位置,设计了轨道加载变形测量实验,并将现场实验测得的轮轨变形数据与仿真结果进行了比较,验证了轮轨接触模型的准确性。研究结果表明,该轮轨接触动力学模型能够为国家天文台50 m射电天线的轮轨磨损和冲击变形提供了参考,也为模型的进一步优化设计提供了依据和思路。 相似文献
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