基于多个隧道掘进机工程数据回归分析的滚刀磨损评价方法

为了评价不同隧道工程围岩对隧道掘进机(TBM)滚刀磨损的影响,解决滚刀磨耗难以准确预测的问题,基于北疆供水二期、吉林引松供水、陕西引汉济渭、大瑞铁路高黎贡山、深圳地铁10号线等多个隧道(洞)工程TMB滚刀磨损数据,选取岩石单轴抗压强度、岩石等效石英含量、岩石磨蚀性指标、岩体完整性指标、滚刀破岩体积磨损速率等参数进行数据回归分析。结果表明：岩石磨蚀性指标与单轴抗压强度和等效石英含量的乘积成对数函数关系,滚刀破岩体积磨损速率与岩体完整性系数和岩石磨蚀性指标的乘积成指数函数关系,滚刀刀圈寿命与岩体完整性系数和岩石磨蚀性指标的乘积成负指数函数关系。并并在此基础上,建立了岩石磨蚀性和滚刀磨损性的分级评价准则。     

滑动摩擦过程中摩擦热分配的实验及有限元仿真研究

摩擦热导致的温升对摩擦副的稳定性有重要影响,而以往对摩擦热及其在界面的分配有广泛的理论研究,但多乏实验测试的验证。实际摩擦过程中由于界面变化的复杂性,摩擦热的分配情况可能与理论预测不同。使用动态热电偶和红外测温的方法对摩擦表面温升进行测量,并使用有限元方法对摩擦界面温度分配进行分析。有限元计算结果表明,固定摩擦副的导热系数高于运动摩擦副时,摩擦热分配呈现明显的时变特征。实验测量与有限元分析的对比表明,材料导热系数会影响磨损界面层对摩擦热的分配;当固定摩擦副的导热系数高于运动摩擦副时,输入固定摩擦副的热量的比例会降低,反之则会升高。     

水润滑艉轴承综合性能实验平台研究

为实现对水润滑艉轴承及其传动系统的综合性能测试,开发了一种水润滑艉轴承综合性能实验平台,设计了实验平台测试方案,并对其重要部件进行了结构设计和动力学分析,结果表明其结构不会发生共振。该实验平台能模拟水润滑艉轴承及其传动系统的复杂工况,在线检测水润滑艉轴承工作转速、转矩、温度、摩擦特性、水膜压力分布、轴心轨迹、噪声、水膜的动刚度系数和阻尼系数等各项参数,为建立水润滑艉轴承系统实验与评价体系,掌握水润滑摩擦副的承载、失效机理与演化规律、摩擦学性能与动态服役行为等关键科学问题提供实验条件。     

有杆泵井管杆偏磨腐蚀试验研究

利用摩擦磨损试验机,对N80、J55两种油管材料与45#钢、35CrMo和20CrMo 3种抽油杆材料配对后在不同矿化度油井污水、温度下进行了摩擦磨损腐蚀试验.结果表明:在低温、低矿化度污水中,管杆磨蚀量相差不大,磨蚀效果不明显;污水矿化度对配对管杆磨蚀影响显著,而在同等污水条件下,磨蚀量随温度的升高略呈上升趋势;从整体来看,35CrMo/J55配对在各条件下的磨蚀量均较小,是较理想的摩擦副.     

角接触球轴承低温摩擦特性与实验研究

为了分析角接触球轴承低温摩擦特性。首先,用有限元软件分析了轴承低温结构变化,仿真分析了轴承低温结构变形、游隙变化和接触角变化。温度降低会使轴承游隙变大,接触角变大,分析了温度对润滑脂黏度的变化。然后,引用现有轴承摩擦力矩计算模型,计算了轴承的摩擦力矩随转速、预紧力、内圈曲率半径系数和温度的变化;分析了低温下轴承各种摩擦力矩的变化趋势。在低温下轴承的流体动压摩擦力矩占轴承总摩擦力矩的80%,润滑脂的黏度系数对轴承的低温摩擦特性影响最大,低温条件下轴承由于弹性滞后引起的摩擦力矩减小。最后,用实验的方法测试了轴承低温摩擦力矩,与仿真结果进行对比,误差在12%以内,证明了计算的准确性,为低温下轴承的使用提供了理论基础。     

往复式摩擦磨损试验机及其计算机控制系统设计

针对不同固体材料在不同条件下的摩擦磨损实验要求,开发设计了一种往复式摩擦磨损试验机,通过测量实验中产生的摩擦力、摩擦系数和磨损量的变化来研究材料的摩擦磨损性能。为提高测试系统的精确性和实时性,将计算机辅助测试系统应用到摩擦学试验当中,通过数据采集系统和测试软件系统完成摩擦磨损数据的实时动态测试,从根本上改变了传统摩擦磨损试验机的缺点。通过对聚四氟乙烯材料的摩擦磨损性能进行实验,证明该试验机性能稳定,测试系统准确可靠。     

磨蚀系数试验台的自动化改造

利用电液比例控制技术和PLC应用技术对磨蚀系数试验台进行了自动化改造,结构简单、经济合理,能可靠地达到控制要求.实现了磨蚀系数试验台系统柔性化、智能化,控制方式灵活,调试方便,极大地提高了该设备的可靠性.实践表明这种方法能有效提高系统的控制精度和设备换向、调速、调压的自动化程度,便于实现机电液一体化,提高了磨蚀系数测量精度.     

基于电机电流分析法及能量特征向量的摩擦实验

对机床类设备的摩擦状态的监测是设备运行过程的一个重要环节。针对机床类设备运行过程中摩擦状态的变化,提出基于电机电流分析法及能量特征向量对摩擦状态进行测试和分析,利用电流信号的小波包变换节点系数重构各频带信号,计算各信号的能量值,构造能量特征向量。通过分析不同时刻各频带信号的能量值,提取包含摩擦信息的特征值能量值,以此作为分析与监测摩擦状态的特征量。实验表明,分析摩擦特征量的变化曲线,可以获得设备工作过程的摩擦状态,有利于实现摩擦状态的在线监测。     

聚氨酯材料液压密封的磨损加速试验方法浅析

采用针盘式往复摩擦仪和液压密封测试机对聚氨酯液压密封进行耐磨性能分析,与现场实际磨损情况进行比较,来确定液压密封的磨损加速试验方法;但是采用液压密封测试机有显著压缩量,采用降低磨损的变色和氧化铝颗粒液压油经往复型针盘式摩擦仪测试则密封面的磨损加速系数2.1～3.4。此实验有益于液压密封耐磨加速实验损设计和PU密封件设计。     

湿式换挡离合器接合过程黏性转矩计算研究

湿式离合器接合过程一般分为纯油膜剪切、混合摩擦、粗糙接触3个阶段,其中黏性转矩发生在纯油膜剪切阶段和混合摩擦阶段。在考虑压差作用和离心力作用下分别计算径向流速和流量,根据修正的雷诺方程牛顿内摩擦定律分别建立摩擦副间油膜厚度模型和黏性转矩计算模型;利用Simulink仿真模块计算得到油膜厚度和黏性转矩;通过引入系数方程修正黏性转矩公式,并通过实验测试和数据采集分析,确定方程中的自变量系数。黏性转矩试验测试曲线与计算曲线的对比验证了计算模型的正确性。计算结果表明:黏性转矩受离心力和压力差作用影响较大;由于流体的可压缩性和流动性使得控制油压作用减弱,由转速导致的离心力对黏性转矩影响则被加强,因此转速对黏性转矩的影响远大于控制油压的影响。     

Abrasion of 0.85% C-Steel under Natural Hawaiian Marine Conditions

A study was undertaken to obtain design data for possible damage scenarios for a planned deep-sea power cable between two Hawaiian islands. The combined results for abrasion and corrosion-erosion of cold drawn 0.85% C-steel armor wire in seawater against seabottom rocks indicate that failure of the proposed design in the desired design life due to these mechanisms is of only intermediate probability. The results also have some general applicability to abrasive wear by and of natural media. The steel and the rock wear simultaneously, with the rock wearing about 150 times faster than the steel. The results can be explained by considering the armor wire as a hard tool causing wear of the rock while abrasion of the steel is caused solely by the hard olivine grains which constitute 6 percent of the rock. Both adjusted wear rates are comparable to laboratory data on abrasion by hard abrasives.     

Wear Mechanisms on Martensitic Steels Generated by Different Rock Types in Two-Body Conditions

The main purpose of this work is to identify and describe complex wear mechanisms that usually occur in the mining environment. Abrasive conditions can differ a lot, especially in the mining industry. Therefore, the need to study the influence of abrasion conditions on the material wear is crucial in order to improve the lifetime and the cost efficiency of the machinery used in such environments. To study various abrasion mechanisms, a cyclic impact abrasion test was used to simulate two-body impact/abrasion. The tests were performed using two martensitic steels, and three different standard rock types of the mining environment were chosen as abrasives, respectively. The wear was indicated as mass loss by measuring the samples before and after the tests. On the other hand, the particle breakage index, which indicates the potential of a rock to wear, was observed by sieving the abrasives before and after the test. The wear results were correlated with different mechanical rock properties. Wear mechanisms were observed using microscopic investigations. The results indicate that different abrasive rock types have a significant influence on the wear rate of the tested martensitic steels. It was observed that by combining different rocks as abrasives, a simulation of the real field was achieved.     

Abrasive wear of steel against gravel with different rock–steel combinations

Wear testing equipment and tests used in research laboratories are often miniature or simplified versions of real applications. For example standardized ASTM dry sand rubber wheel abrasion test G 65 and pin abrasion test G 132 are widely used to study materials’ abrasion wear resistance. The test results, however, do not always correlate too well with the results obtained from real wear conditions. One reason for this is, for example, that in the crushing applications of mining industry the abrasive size is usually much larger than that used in the laboratory wear tests. To study the abrasive wear caused by larger size gravel, new three-body abrasion test equipment was therefore constructed. The equipment uses the pin-on-disk principle with free abrasive particles of sizes up to 10 mm. During the test the pin is repeatedly pressed against a fixed amount of abrasive that is rotating with the disk having confining walls. As the pin is prevented from touching the counterbody, only the abrasive acts as the wearing agent.Three steels of different hardnesses were cross-tested as pin–disk pairs and as pins against a rubber disk using three igneous rock gravels with different crushability properties as abrasives. The wear was measured as mass loss from both the pin and the disk, and the rock comminution was measured by sieving. The results indicate that the mechanism of wear is greatly affected by the hardness of the counterbody. When using large size abrasives, the rate of comminution is also a very important factor that can significantly affect the wear test results.     

超音速火焰喷涂WC-Co涂层耐磨性研究

利用超音速火焰喷涂（HVOF）工艺制备了WC-Co涂层，测定了涂层孔隙率、显微硬度及干摩擦磨损过程中涂层材料失重，得出涂层干摩擦因数随时间的变化关系，分析了涂层摩擦磨损机制。结果表明，WC-Co涂层致密，平均孔隙率为1．29％，显微硬度达1140HV（测试载荷2．94N），干摩擦条件下材料失重低于电镀Cr镀层2个数量级；摩擦初期，干摩擦因数迅速增加，主要磨损特征是粘结相富Co区的犁沟切削，摩擦中后期，摩擦副间实际接触面积增大，摩擦因数变化较小，磨损趋于稳定。WC-Co涂层的主要磨损机制是疲劳磨损和犁沟切削。     

托辊阻力系数的微机测试系统及其数据处理

阐述托辊阻力系数测试仪的测量原理,给出该仪器的结构原理图,设计计算机辅助测试系统及其阻力系统测试数据处理软件的结构,并给出测试数据处理主模块流程图。     

Correlation of physico-mechanical properties of granitic rocks with Cerchar Abrasivity Index in Turkey

During the last decades, the rapid developments in mining operations and tunnel construction have lead to a rapid increase in the number of excavation machines. In order to achieve the expected benefits of mechanical excavation machines, these machines should be selected in accordance with the characteristics of rocks. Tool abrasion is an important factor in hard rock tunnelling, mining, and it is highly affected by rock abrasivity. There are several methods to identify the rock abrasivity. One of the commonly used abrasion test in rock is the Cerchar abrasivity index (CAI). Before selection and implementation of excavating machines, physical and mechanical properties of the rocks should be determined. It’s known that, physical-mechanical properties of granitic rocks are generally better than those of many rock types although they cause some difficulties (tool wear, lost time, etc.) in excavation and increase the cutter costs. The purpose of the present study is to determine empirical relationships between CAI and physical-mechanical properties of different granitic rocks using regression method. In this study, some laboratory experiments were conducted on samples collected from granite quarries in different parts of Turkey, particularly from the Marmara Region. Firstly, petrographical, mineralogical and physical-mechanical characteristics of the collected granitic rocks were determined. Then, empirical relationships between these properties and CAI were determined using method of regression analysis. According to the results obtained, a strong correlation is found between CAI value, quartz content and quartz size of the granitic rocks. In addition, the uniaxial compressive strength and indirect tensile strength of the studied granitic rocks increase as CAI increases. Surface roughness, waviness and peak number of granitic rocks lead to an increase in CAI. On the contrary, Bohme abrasion resistance increases while CAI decreases.     

显微观察手段在机械摩擦磨损研究中的应用

选择机械零件常用的材料作为试样,在M-200型磨损试验机上对试样进行摩擦磨损试验。试验后对试样进行一系列处理后,用L2003A型金相显微系统和S-570型扫描电镜仪对试样进行金相组织观察和表面扫描,从而研究材料的磨损和显微表面变化的机理。试验结果表明：试样表面有颗粒脱落,某些试样表面有微小固相焊合点,磨损恶劣部位表面的金相组织发生变化;试样摩擦磨损后的表面形貌大部分主要表现为摩擦磨损造成的划痕和擦伤。     

滚齿加工中滚刀的磨损分析与对策

滚齿在齿轮加工中占有重要的地位,自有滚齿加工工艺开始,人们就一直对滚刀的磨损问题进行研究。文章以实验数据为根据,分析了滚齿加工中刀具的磨损原因,提出了合理使用刀具的有效方法。     

两种受电靴材料与不锈钢带电接触摩擦磨损特性的试验研究

在销-盘式摩擦磨损试验机上分别进行了不锈钢／铜基烧结合金材料和不锈钢／铜石墨烧结材料接触的载流摩擦磨损行为的试验研究。在试验中记录了摩擦因数和磨损量的变化，并对磨痕形貌进行了光学显微镜观察。结果显示，电流对2种摩擦副带电接触的摩擦磨损行为有重要的影响。2种材料的摩擦因数随电流的增大而呈现截然相反的变化趋势，但两者的磨损量却随电流的增加而增大。不锈钢／铜基烧结合金材料的磨损机制主要是粘着磨损及氧化磨损。不锈钢／铜石墨烧结材料磨损机制包括磨粒、粘着磨损和电弧烧蚀，其中电弧烧蚀对磨损量的影响随电流的增大而增加。