某款摩托车后轮圈断裂分析

在轮圈的设计中,运用有限元分析技术是非常有必要的,它和场地恶路试验一起可以有效预测并发现轮圈设计时的强度问题,并进行优化设计来避免。通过对优化后的轮圈1 000 km恶路路况试验后,无异常情况发生,说明优化方法是可行的、有效的。     

A study of polygonal wheel wear through a field test programme

High magnitude impact loads caused by polygonal wear of the wheels have been associated with in-service failures of structural components of high-speed railways, although the mechanisms leading to wheels’ polygonalisation is not yet fully understood. In this study, a long-term field test programme is undertaken and the data are analysed to gain better understanding of the growth in polygonal wear, and its characteristics and correlation with the axle box acceleration. The field measurements on a high-speed railway involved monitoring of wheels profiles between successive re-profiling of the wheels so as to identify the rate of growth of wear in addition to the axle box acceleration. The data suggested rapid growth in wheel wear, which could be characterised by polygonal wear of nearly 18th and 19th harmonic order. It is further shown that the magnitude of axle box acceleration increased considerably with increasing wear magnitude of the wheel.     

断开式平衡轴端盖螺栓拧紧工艺方案设计

本文从断开式平衡轴端盖螺栓的连接结构出发,分析了该结构的拧紧特点,设计了螺栓拧紧的工艺方案.     

负压吸气装置在摩托车铝合金车轮模具上的应用

产品模具安装负压吸气装置后,经生产3个批次产品检查确认,轮辋和轮辐加工面的气孔和针孔大幅减少,材料强度均有较大幅度提升,针孔数量明显减少,产品的外观和材料强度完全达到相关技术要求,客户确认合格。     

发动机12.9级连杆螺栓的材料与工艺

为实现12．9级螺栓的国产化,以发动机连杆螺栓为对象,研究了12．9连杆螺栓的材料和工艺。研究结果表明,35CrMo钢是发动机12．9级连杆螺栓的优良材料,可满足12．9级螺栓材料的力学性能要求。对12．9级连杆螺栓采取氮气保护热处理、杆部缩细冷镦、热处理后滚丝是可行的工艺方法,可生产出高质量、高精度螺栓,而且满足批量生产要求。     

某轻型客车轮毂轴承的匹配计算

某汽车厂家为迎合市场需求,开发了一款轻型客车。该车型在试验场路试过程中,发生了两起前轮毂轴承烧蚀问题。本文针对该问题,运用理论计算、CAE分析,并结合试验,制定相关措施,优化设计轮毂轴承。     

The role of the contact geometry in wheel–rail impact due to wheel flats

A thorough investigation of wheel–rail impact due to wheel flats is presented, together with a quantitative characterization of the main mechanisms and parameters. A criterion for the speed with respect to contact loss between wheel and rail is derived. In the subcritical speed regime, the magnitude of the impact force is shown to be directly related to the geometry of the flat, whereas in the transcritical speed regime a fictitious or effective flat depth exists, which decreases with the second order of the speed. In this domain, the position of impact shifts towards the end of the flat with increasing speed. The impact force increases with the second order of the speed in the subcritical speed regime and approximately the first order of the speed in the transcritical speed regime. The magnitude of the impact force is inversely proportional to the minimum circumferential curvature of the wheel tread defect in the subcritical speed regime, and to the effective minimum curvature in the transcritical case. The variation with the flat depth is less; the impact varies with the square root of the flat depth. The presented theory is in accordance with measurements reported in the literature and explains characteristic features in them.     

基于改进BP神经网络的车轮定位参数动态测量

结合人工神经网络(ANN)技术，提出了基于改进的BP神经网络的车轮定位参数动态测量方法，编制了相应的程序，并进行了试验验证。结果表明，通过将车辆前进时的侧滑量作为已训练好改进BP神经网络的输入，根据网络的输出值可以有效地识别出车辆行驶时的车轮外倾角与前束值，从而实现在侧滑试验台上对车轮外倾角和前束值的测定，并依据测定结果有效地指导检修人员进行车轮外倾角与前束值的调整。     

高速铁路噪声计算方法

根据离开轨道中心15m处高速铁路的噪声暴露声级,通过引入地面衰减、屏障衰减和房屋建筑及树木的附加衰减参数,建立噪声理论分析模型。导出预测高速铁路牵引噪声、轮轨噪声和空气动力噪声的理论计算式。对秦沈客运专线铁路噪声进行了预测。经与实测数据进行对比,数据吻合良好。     

轮轨系统高频振动研究

通过建立轮轨系统高频振动模型,分析轮轨相互作用关系,给出车轮及钢轨的高频振动功率谱计算式,并且推导了车轮、钢轨阻抗特性,计算因轮轨表面粗糙度而引起的轮轨高频振动响应。表明大约在1300Hz以下频段,主要以钢轨振动为主,而在1300Hz以上频段,车轮振动占主导地位。