共查询到19条相似文献,搜索用时 62 毫秒
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车轮是汽车零部件中的A类核心部件,车轮的安全性能直接影响汽车的正常行驶。车轮在工作过程中受到随机载荷的作用,车轮的疲劳寿命问题是核心问题。目前主要采用弯曲疲劳试验和径向疲劳试验作为车轮疲劳寿命的试验方法,但这两种试验只考虑单一载荷工况,导致试验结果与实际情况有较大出入。车轮双轴疲劳试验是一种全新的试验方法,同时考虑多向载荷对车轮的影响,可以较为真实地反映车轮在实际运行过程中的受力情况。试验周期长、成本高是车轮双轴疲劳试验的缺点。以铝合金车轮为例,进行车轮双轴疲劳试验仿真分析,通过对比仿真结果与实际试验结果,验证仿真分析的有效性和可靠性,进而为企业缩短车轮研发周期,降低车轮研发成本提供支持。 相似文献
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将动态接触转化成节点可相对移动的缓冲过渡层,提出径向疲劳模型中轮胎与轮辋接触问题的解决方法.过渡层通过共用节点的方法离散成五面体单元,传递轮胎对轮辋的作用力.由于过渡层刚度很小而且厚度小,所以对车轮刚度的影响可以忽略不计.考虑到试验中转鼓与车轮的滚动接触切向力比较小,仅以等效的径向压力施加到轮胎上.文中建立整个试验过程的有限元模型,通过与试验结果以及前人的成果相对比,表明分析模型是正确而有效的. 相似文献
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随着重载列车的不断发展,辐板的热-机疲劳成为车轮破坏的主要形式。基于Ansys有限元软件,对车轮辐板的制动热应力进行分析,利用单轴疲劳准则和Haigh-Goodman疲劳极限图对车轮辐板进行疲劳评估。分析了制动热应力对车轮辐板单轴疲劳的影响。结果发现:(1)未考虑制动热应力下,新制轮和磨耗轮辐板的各节点的抗疲劳性能均满足要求;制造态残余应力使辐板的疲劳薄弱位置发生了转移;最易发生疲劳的截面为0°、180°和40°~60°。(2)考虑制动热应力下,新制轮和磨耗轮辐板的各节点的抗疲劳性能均满足要求,但是在FPH和BPR处平均应力未能达到安全要求。 相似文献
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弯曲疲劳寿命是汽车车轮重要的性能指标,目前其预测方法仍局限于传统的名义应力法或局部应力应变法,没有考虑微观组织和铸造缺陷对疲劳寿命的影响,预测铝合金车轮在低应力水平下的高周疲劳寿命时与实际情况存在相当差距。基于小裂纹扩展理论,建立低压铸造铝合金A356-T6车轮的以二次枝晶臂间距、针孔尺寸为参数的疲劳寿命预测模型。实现铸造模拟、有限元分析与疲劳分析的集成,初步建立起综合铸造过程、铸造缺陷以及相关下游制造工艺对车轮力学性能影响的平台。以某型车轮为例,采用该方法预测其弯曲疲劳寿命,试验验证预测结果比Simth-Waston-Topper方法更为准确。 相似文献
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根据起重机车轮的工作应力和疲劳强度的概率分布,采用疲劳可靠性设计方法,对车轮进行分析计算,建立车轮许用轮压与起重机机构工作级别、车轮直径、轨道曲率半径及材料疲劳强度极限等因素之间的关系,为起重机车轮的合理选用提供了一种理论依据。 相似文献
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重载货车车轮踏面制动辐板热应力分析 总被引:1,自引:0,他引:1
采用大轴重货车是解决我国铁路货运能力不足的主要途径之一,然而提高轴重意味着车轮踏面所受的制动热负载将会增大,这可能导致大轴重货车车轮辐板热损伤加剧。因此,有必要通过对不同轴重车轮热应力的对比分析,揭示轴重大小对车轮辐板损伤的影响规律,为制定大轴重货车运行和制动条件提供支持。提出研究此问题的新思路,采用热弹塑性有限单元法,模拟在热处理工艺过程中车轮辐板残余应力分布状况,使得车轮存在仿真制动工况所需的初始残余应力。对重载运煤专线—大秦线全程循环制动进行模拟,计算得到车轮制动功率—时间历程,仿真在此工况下30 t重载货车车轮辐板的温度场和热应力场的分布状况。计算比较21 t、25 t和30 t轴重货车车轮在大秦线全程循环制动中热应力和制动完全结束后的残余应力的变化规律。结果表明,车轮在热处理后,车轮辐板残余应力是不可忽视的。随着轴重的增大,车轮辐板将承受更大的热应力和残余应力。 相似文献
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轮毂弯曲疲劳试验的仿真分析 总被引:2,自引:0,他引:2
通过仿真分析和经验总结,找到了轮毂能通过弯曲疲劳试验的极限应力。在产品的设计阶段就可以判断出不能通过试验的薄弱位置,进而通过修改产品设计预先避免不合理的应力分布,并且在实际的应用中,证明了此方法的可行性。 相似文献
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This paper concerns the modelling of the rolling contact fatigue of a railway wheel steel, which is simulated with moving Hertzian contact pressure. Parametric studies are carried out with a two-dimensional elastic-plastic finite element model of a part of a wheel containing defects. Several parameters, namely the size and shape of material defects, the load magnitude and the friction coefficient are varied to investigate their effect on the railway wheel fatigue damage. Defects or small friction coefficient are a plausible explanation to the initiation of deep subsurface fatigue cracks. 相似文献
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根据UIC510-5标准,使用单轴疲劳准则对辐板非孔区域进行分析,应用Crossland和Dang Van多轴疲劳准则分析定位销安装孔和螺栓孔的疲劳强度,分析结果表明:制动盘的安装使辐板孔区域、辐板与轮毂过渡区域,以及辐板与轮辋过渡区域的最小安全系数增大;螺栓预紧力由47.62k N增大至64.94k N,车轮辐板各区域的安全系数变化较小;相对于Crossland准则,使用Dang Van多轴疲劳准则评定辐板孔区域疲劳强度得到的安全系数较小;车轮辐板区域最小安全系数为1.17,其疲劳强度满足要求。 相似文献
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The cause of the ICE train derailment, which occurred in 1998 at Eschede, was fatigue failure originating on the inside of the wheel tire. Rubber-sprung resilient wheels were used for the trailer cars. The wheel tire is mounted on the wheel disc. Thirty-four rubber pads were arranged between the wheel disc and the wheel tire. It was postulated that fretting fatigue between the rubber block and the inner side of the tire might have an influence on the initiation of the incipient crack. In order to clarify the influence of the rubber contact on the fatigue strength of the tire, fretting fatigue experiments under rubber contact conditions were performed. During the fundamental fretting fatigue test using bridge pads and small size carbon steel specimens, no typical fretting damage such as fretting wear and minute cracks were observed due to contact of the rubber. Stress conditions of the rubber-sprung wheel under vertical and lateral wheel loads were evaluated by a three-dimensional elastic stress analysis. Since the rubber is a super-elastic material, the Mooney-Rivlin model was used in the FEM calculation. It was found that the wheel tire is subjected to a cyclic stress during one revolution of the wheel and the maximum stress occurred at the center of the inner surface of the tire where the fatigue crack initiated. Fatigue strength of the wheel tire was determined by the rotating bending fatigue testing of specimens taken from the tire. It was found that the tire with an 862 mm diameter at a wheel load of 80 kN had a safety factor more than 3.5 from a fatigue limit diagram with a failure probability of 0.01. To confirm the fretting damage under the rubber contact and the result of the fatigue strength evaluation, fatigue tests of a full size wheel were made. After 20 million cycles at the wheel load of 280 kN, which was just below the endurance limit estimated by the endurance limit diagram, no fretting damage and no fatigue cracks were observed. The wheel was, however, fractured at 1.56 million cycles under the maximum load of 308 kN, which was just above the endurance limit. The estimation of the safety factor of 3.5 estimated from the endurance diagram was confirmed by the full size fatigue testing. It was concluded that there was no effect of fretting due to the rubber contact on the fatigue strength of the rubber-sprung single-ring railway wheel. 相似文献
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针对铝合金轮毂有限元分析模型中的应力集中和强度富余情况,利用ANSYS软件对其进行结构优化,使其应力分布更加合理,达到了提高材料的利用率和减轻自重的目的.优化后的轮毂通过了弯曲疲劳试验、径向疲劳试验和冲击试验,且试验结果与有限元分析结果基本吻合,从而论证了该轮毂研发途径的可行性. 相似文献