共查询到20条相似文献,搜索用时 15 毫秒
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针对湿式离合器试验过程中磨合状态的预测问题,提出利用摩擦转矩信号分形特征来预测和评价磨合状态的新方法.首先,分别阐述了摩擦转矩信号盒子维数和关联维数的计算方法;然后,在湿式离合器试验台上提取了磨合试验的摩擦转矩信号,并对信号进行了自相似性分析;最后,应用盒子维数和关联维数分别对摩擦转矩信号进行了分形研究.分析结果表明:盒子维数和关联维数都能定量描述试验过程中摩擦转矩信号的分形特征,随着磨合次数的增加,摩擦转矩信号的盒子维数和关联维数的波动范围都逐渐减小,并且最终收敛于较小的波动范围.因此,利用试验中摩擦转矩信号的分形特征能够在不开箱条件下定量地预测和评价湿式离合器的磨合状态. 相似文献
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L. F. Coffin Jr. 《摩擦学汇刊》2013,56(1):139-150
Various material combinations are investigated in the form of thrust bearings in such fluids as sodium-potassium eutectic, xylene and spindle oil. It is found that with these fluids certain material combinations can be made to perform satisfactorily as hydrodynamic bearings by a process of wearing-in. With these unique combinations it is possible to obtain film thicknesses of the order of 10 × 10?6 inches by extreme wear-in. The characteristics of bearings worn in to this degree are reported and mechanisms for the observed effects discussed. 相似文献
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Russian Engineering Research - The use of ultrahigh-molecular-weight polyethylene (UHMWPE) in manufacturing is proposed—in particular, for the cuffs of hydraulic drives. The properties of... 相似文献
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This paper describes failure processes in plastic rollers that undergo rolling contact, and the effect of initial surface roughness upon wear and rolling fatigue. Experiments were performed with mating cylindrical rollers of high-density polyethylene (PE rollers) and chrome-plated cylindrical driving rollers. Surface roughness of the PE roller is affected by three successive transition processes. In the first period, the amount of wear can hardly be measured, although a reduction of surface roughness is noted. During the second period, wear occurs in proportion to the initial surface roughness. In the third period, wear becomes independent of the initial surface roughness, and increases in a manner exponential to load. At the end of this period, small cracks appear randomly, and grow into pits. Roller fatigue Life, defined by the time when cracks appear, is shown by an S-N curve. It is found that fatigue limiting stress, represented by Hertz stresses, is about 107pa. 相似文献
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The tribological (friction and wear) behaviour of different polymeric materials was evaluated for hip prostheses applications. First, three polymeric materials were tested with fixed conditions of contact stress and sliding velocity. In a second phase, the material which presented the best results was selected. Its frictional behaviour under dynamic conditions of contact stress and sliding velocity was evaluated. 相似文献
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A mechanism is proposed for orienting motion of anthropomorphic robots and arm prostheses, with limited rotation of the output component. The linear displacements and drive forces required for specified rotations and the torques at the output component are determined. A simplified control algorithm is devised. 相似文献
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《机械设计与制造》2017,(12)
影响非骨水泥假体长期稳定的因素是无菌松动,微动和应力遮蔽通过破坏假体近端的骨整合导致假体的无菌松动,而微动和应力遮蔽与假体的力传递相关。定制式假体的设计模型来源于病人股骨的CT数据,它建立了有限元模型与手术模型的一致性,通过有限元模型上的力传递分析,优化假体的设计和假体与髓腔的匹配,控制手术后假体上的力传递,避免假体近端大的微动和应力遮蔽而破坏假体在髓腔中的初期稳定性,促进假体近端的骨整合。针对定制式假体,发展一种新型的集成技术,形成定制式假体设计、有限元分析和制造一体化,特别是采用CAD/CAM/Robot集成技术加工定制式假体,在建立CAM软件空间各单元与机器人工作空间对应各单元一致性基础上,提高了假体的制造精度。仿真和实验结果表明,有限元分析方法可以控制假体上的力传递,机器人磨削柄体的误差小于0.9mm。 相似文献
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高密度聚乙烯硅芯塑料管拉伸强度测量的不确定度评定 总被引:1,自引:0,他引:1
介绍了用CSS44100电子万能试验机测定地下通信管道用高密度聚乙烯硅芯塑料管拉伸强度的试验方法,并对试验结果的测量不确定度进行分析评定,找出了影响拉伸强度测量结果的主要因素。 相似文献
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聚乙烯,聚氯乙烯薄膜在冷冲压拉深工艺中的应用 总被引:1,自引:0,他引:1
结合生产工艺,本文介绍了聚乙烯(PE)、聚氯乙烯(PVC)薄膜在拉深工艺中的应用,分析了聚合物薄膜的摩擦性能,润滑机理,重点论述了PE,PVC薄膜在小型单缸柴油机油底壳拉深工艺中的润滑作用,结果表明固体润滑剂具有比油脂润滑剂更优越的性能,同时指出,聚乙烯、聚氯乙烯等聚合物自润滑薄膜在金属塑性加工工艺中具有广泛的应用价值。 相似文献
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