Expert Experience and Data-Driven Based Hybrid Fault Diagnosis for High-SpeedWire Rod Finishing Mills

The reliable operation of high-speed wire rod finishing mills is crucial in the steel production enterprise.As complex system-level equipment,it is difficult for high-speed wire rod finishing mills to realize fault location and real-time monitoring.To solve the above problems,an expert experience and data-driven-based hybrid fault diagnosis method for high-speed wire rod finishing mills is proposed in this paper.First,based on its mechanical structure,time and frequency domain analysis are improved in fault feature extraction.The approach of combining virtual value,peak value with kurtosis value index,is adopted in time domain analysis.Speed adjustment and side frequency analysis are proposed in frequency domain analysis to obtain accurate component characteristic frequency and its corresponding sideband.Then,according to time and frequency domain characteristics,fault location based on expert experience is proposed to get an accurate fault result.Finally,the proposed method is implemented in the equipment intelligent diagnosis system.By taking an equipment fault on site,for example,the effectiveness of the proposed method is illustrated in the system.

EXPERIMENTAL STUDY ON HIGH-SPEED CENTRIFUGAL PUMPS WITH DIFFERENT IMPELLERS

The experimental study is carried out on high-speed centrifugal pumps withthree different impellers. The experimental results and analysis show that high-speed centrifugalpumps with a closed complex impeller can achieve the highest efficiency and the lowest headcoefficient followed by those with half-open impeller and open-impeller, and can obtain much easilystable head-capacity characrastic curve, while those with a half-open complex impeller can't. Thecharacteristic curve with a open impeller is almost constant horizontal line before droppingsharply. The results also show that the axial clearance between pump casing and impeller caninfluence greatly on the performance of centrifugal pumps.

NUMERICAL AND EXPERIMENTAL INVESTIGATION OF WAVE DYNAMIC PROCESSES IN HIGH-SPEED TRAIN/TUNNELS

Numerical and experimental investigation on wave dynamic processes induced by high-speed trains entering railway tunnels are presented. Experiments were conducted by using a 1:250 scaled train-tunnel simulator. Numerical simulations were carried out by solving the axisymmetric Euler equations with the dispersion-controlled scheme implemented with moving boundary conditions. Pressure histories at various positions inside the train-tunnel simulator at different distance measured from the entrance of the simulator are recorded both numerically and experimentally, and then compared with each other for two train speeds. After the validation of nonlinear wave phenomena, detailed numerical simulations were then conducted to account for the generation of compression waves near the entrance, the propagation of these waves along the train tunnel, and their gradual development into a weak shock wave. Four wave dynamic processes observed are interpreted by combining numerical results with experiments. They are: high-speed trains moving over a free terrain before entering railway tunnels; the abrupt-entering of high-speed trains into railway tunnels; the abrupt-entering of the tail of high-speed trains into railway tunnels; and the interaction of compression and expansion waves ahead of high-speed trains. The effects of train-tunnel configuration, such as the train length and the train-tunnel blockage ratio, on these wave processes have been investigated as well.

Prediction of high-speed train induced ground vibration based on train-track-ground system model

The development of analysis on train-induced ground vibration is briefly summarized. A train-track- ground integrated dynamic model is introduced in the paper to predict the ground vibration induced by high-speed trains. Representative dynamic responses of the train-track-ground system predicted by the model are presented. Some major results measured from two field tests on the ground vibration induced by two high-speed trains are reported. Numerical prediction with the proposed train-track-ground model is validated by the high-speed train running experiments. Research results show that the wheel/rail dynamic interaction caused by track irregularities has a significant influence on the ground acceleration and little influence on the ground displacement. The main frequencies of the ground vibration induced by high-speed trains are usually below 80 Hz. Compared with the ballasted track, the ballastless track structure can produce much larger train-induced ground vibration at frequencies above 40 Hz. The vertical ground vibration is much larger than the lateral and longitudinal components.

平板式永磁电动悬浮系统设计与实验研究

该文提出一种以汽车为载体的平板式永磁电动悬浮系统,并从结构设计、等效实验、原理样机测试三方面对电磁特性开展研究。首先,阐述系统的结构及原理,依托自主研制的最高时速600 km的动轨实验台,分析在固定参数下的电磁力特性和垂向自稳定能力,并验证有限元模型的准确性。其次,对悬浮磁体、导向磁体、导体板进行计算分析。最后,改装汽车,加装间隙调节机构、简易悬浮架、车载磁体及测试系统,并搭建长50 m的铜制导体板轨道,开展原理样机测试。整车约为1500 kg,最高实验速度为70 km/h,最大悬浮间隙约为35 mm。实验结果验证了导向磁体的有效性,展现出平板式永磁电动悬浮系统较强的载重能力。

The influence of the leading-edge angle of subgrade on the aerodynamic loads of a high-speed train in a wind tunnel

The purpose of this study is to establish the correlation between the boundary layer over the subgrade and the aerodynamic loads act-ing on the train model in conventional wind tunnel tests.Firstly,flow characteristics around the subgrade with different leading-edge angles(15°,30°and 45°)are investigated through the particle image velocimetry(PIV)experimental test method.Then,wind tunnel tests of the aerodynamic performance of a high-speed train are carried out.The results are compared with previous experimental data obtained by moving model tests.Results show that,due to the presence of a boundary layer,the pressure acting on the lower part of the train head decreases,while other locations are not significantly affected.This is the reason for the reduction of the aerodynamic drag and lift on the train.In addition,the reduction effects become more obvious when the thickness of the boundary layer increases.The experimental results obtained could serve as a calibration of aerodynamic forces for wind tunnel tests on high-speed trains.

Numerical and experimental studies on unsupervised deep Lagrangian learning based rotor balancing method

Rotor balancing is essential to rotor dynamic analysis.To make the balancing process convenient and costless,a balancing method using unsupervised deep Lagrangian network without weight trail is proposed.In the proposed network,a Lagrangian layer is applied to the network to introduce the physical prior knowledge.Compared to traditional balancing method,trail weight process is not necessary.Meanwhile,parameter sharing mechanics in baseline design or Lagrangian layer are applied to identify the unbalanced force without labeled data.Both numerical case study and corresponding experiment are conducted to validate the method.Both experimental and numerical results find that the proposed rotor balancing approach gives reasonable and comparative results with the considerations of both cost and accuracy.Compared with the baseline,to which no physical prior is applied,the balancing method with Lagrangian mechanism involved could achieve better performance.This proposed rotor dynamic balancing method gives out an alternative approach of rotor balancing methods.

超级稻单茎秆切割力学性能试验

在自制的切割试验台上对超级稻单茎秆切割力学特性进行了试验。根据测量获取的切割力连续变化曲线计算了6种超级稻样本的切割功耗,分析了切割速度、切割位置以及切割刀具组合对茎秆切割力和功耗的影响。结果表明：不同品种超级稻单茎秆峰值切割力达到24~32 N,随着切割位置的提高切割力有小幅下降趋势,峰值切割力和切割功耗随茎秆截面积的增大几乎呈线性增加,随着切割速度的增加而逐渐减小。

盾构掘进机关键技术及模拟试验台现状与展望

针对盾构机在掘进过程中穿越复杂地质时,负载和动态过程难以用理论模型准确描述的难题,采用模拟试验方法完善盾构设计和取得关键技术的突破.归纳盾构设计和制造中所涉及到的6项关键技术,介绍盾构掘进模拟试验方法及模拟试验中的相似关系,重点论述体现盾构模拟试验技术先进性的模拟试验平台的研制进展和现状.结合工程实际和未来发展趋势,分析并总结现有模拟试验平台存在的局限性,研制具有功能多样且集成度高、模拟地质环境覆盖范围宽、掘进土体边界影响小等特点的新一代盾构综合模拟试验平台.

SD振子的设计及非线性特性实验研究初探

具有光滑与不连续转迁特征的SD振子发现和提出以来,引起了广泛关注.基于双稳系统大位移特征的测量法困难,SD振子的实验研究还未见报道.该文提出并设计了具有SD振子系统光滑特征的非线性实验装置,用实验的方法揭示由几何关系产生的强非线性系统的非线性动力学行为.设计的非线性实验装置基本振动参数均有良好的可调性和可测量性,对SD振子在不同频率及幅值的简谐激励作用下的非线性动力学响应进行了实验研究.为克服大位移测量难题,研究采用高速摄像机采集振子振动视频信号并进行分析.结果表明,SD振子系统在一定的参数条件下会产生周期振动、周期5振动及混沌运动等复杂非线性动力学现象,在相同实验参数条件下进行了数值仿真,仿真结果与实验结果一致.

自升式钻井平台插桩分析的几个关键问题

独立桩脚自升式钻井平台在我国海洋石油勘探开发中的应用已有三十多年的历史,在长期平台插桩分析工作的基础,虽然积累了丰富的经验,但面对新的勘探区域,也会出现预测不准的情况。究其原因主要是对场地土质条件了解不够充分、土质参数评价不够准确、计算模型过于单一和地区经验积累不足等。为提高插桩分析结果的准确性,通过多次工程插桩实践,总结了插桩分析几个需重点关注问题。结合某工程实例,在考虑这些关键问题的基础上,得到插桩分析预测结果与实际插桩结果基本吻合。

人体站姿竖向振动等效单自由度模型参数研究

人体单自由度简化模型应用广泛,但其参数取值尚未有统一标准。在前人研究的基础上提出等效模型参数的思路,并进行了相关动力学理论推导和物理意义分析。为得到模型参数,采用两种不同原理的单自由度振动台对人与结构耦合自由振动进行了测试和数据分析。实验数据拟合结果表明,该模型具有较好的精度和应用价值,所得结果在一定范围内与相关参考文献的分析结果表现出良好的一致性。结论是当人体与不同参数的结构耦合振动时,由于主振型的变化将表现出不同的单自由度等效自振频率和阻尼比,另外局部肢体姿态对等效参数的取值也有一定影响。

数控微米刨切试验台的设计与试验

为解决传统热磨法加工微米薄木片及木纤维中高能耗、工序复杂、加工成本高的缺点,现改变加工方法,采用顺纹纵向刨切木材的方式,研发了数控微米刨切试验台。试验台主要由机架、纵向进给机构总成、工件夹具、控制面板、刨切机构总成、升降机构总成和限位机构组成,可对宽度为50 mm,长度为300～600 mm,高度为20～90 mm的木材工件进行纵向进给、切削量进给和刨切作业。笔者对试验台整机以及各机构进行设计,并通过ANSYSY对刀具进行强度校核。通过试验,确定刨切机构切削角δ取45°,刀刃伸出量h取0.05 mm,刀门宽度d取0.2 mm,刨得的木片平均厚度为18.7μm,最薄为15μm。最后通过显微镜观察发现经过刨切后的刀刃部分出现磨损,可通过表面改性提高刀具的耐磨性。

机车车辆滚动振动试验台标定试验研究

为了对机车车辆滚动振动试验台的性能、试验方法以及线路试验结果与试验台试验结果的比较等方面进行深入研究，通过试验台动力性能试验得到了试验台的一些基本性能参数；由线路试验得到了试验样车的轴箱加速度响应，在试验台上利用波形再现技术，反推出了相应的轨道不平顺信号；并利用该信号在试验台上进行了车辆的动力学性能试验，给出了试验结果。

竖直平板水膜表面波演化行为实验研究

设计与搭建了大尺寸水膜稳定性实验台,并进行了竖直平板上降水膜表面波过程参数演化实验。实验中水膜Re的范围为300～1 350。借助高频电容式水膜测厚仪和高速摄像仪等测量设备对水膜表面波速率、波长、频率等参数随平板沿程位移增加的演化行为进行了测量与分析。实验结果表明:中低水膜Re条件下表面波运动速率、波长和频率与沿程位移弱相关;同时,在仔细观察整个小波交融现象演化过程的基础上,对小波交融特征进行了总结。

大温差空气源热泵热水器实验台的研制

介绍了研制本实验台的背景,给出了实验台的工作原理图及各主要部件的技术参数。通过实验(在人工环境实验室内)分别对实验台在单级压缩模式及双级压缩模式下的运行特性进行分析比较,显示在低温工况下双级压缩模式的运行性能比单级压缩模式有很大提高。系统设计合理,运行可靠。为进一步研究大温差风冷热泵热水器创造了条件。

竖直平板降水膜表面波波动特性实验研究

设计与搭建了大尺寸水膜稳定性实验台,并进行竖直平板上降水膜表面波波动特性实验研究。实验中水膜雷诺数Re的范围为20～1 200。借助电容式水膜测厚仪和高速摄像仪对水膜表面波形态、波幅、波速和波频等过程参数进行测量与分析。实验结果表明:中低水膜Re条件下孤波振幅、弧波波速分别与水膜Re成正比;孤波频率与水膜Re成弱相关性,入口扰动条件与初始轮廓对孤波频率的影响远大于水膜Re的影响。

CTR120/300复合连续油管钻机研制与试验

连续油管钻井技术是20世纪90年代从北美地区迅速发展起来的一项高效、低成本、安全环保的钻井技术。四川宏华石油设备有限公司成功研发了国内首台复合连续油管钻机,名义钻井深度(Φ114.3mm钻杆)2 000m。钻机的主要设备由移动运输性好的3台拖挂单元组成:连续油管井架底座拖挂单元、连续油管滚筒拖挂单元和机械手拖挂单元。该钻机将连续油管装置和带动力水龙头的常规钻井装置集成在一起,既能进行常规钻杆钻井,又能进行连续油管钻井。钻机配备的全套自动化管子处理装置、轻便铁钻工、自动液压卡瓦等机具,极大地减少了钻台面的作业量,降低了劳动强度。钻井试验结果表明,CTR 120/300复合连续油管钻机总体性能符合设计要求,与常规钻井相比具有起下钻速度快、机械钻速高、钻井液连续循环等优点,但还需要进一步加强井下工具和钻井工艺的研究,以加快其在国内的推广应用和发展。

深井钻机K型井架的动力模型设计

动力模型试验是研究深井钻机井架的动力特性的有效方法。为制作井架的动力模型,基于相似理论分析了K型井架动力模型与原型之间的相似准则,采用量纲分析以及方程式分析法推导了井架各相似判据的相似比,并以此为依据设计出井架模型。为满足加工工艺的要求,对部分杆件的长度和截面做了适当调整,在此基础上采用有限元软件分别对井架模型和原型进行模态分析,通过对比验证,发现前6阶模态频率的最大相对误差仅为7.70%,说明井架模型能准确反映原型的动力特性,该模型的设计合理。本设计结果为深井钻机井架的模型试验打下了基础。

汽车空调压缩机耐久性试验台设计

汽车空调压缩机是汽车空调系统的核心,耐久性试验是汽车空调压缩机最重要的试验之一。本文介绍了汽车空调压缩机耐久性试验台的设计依据、试验台工作原理、系统设计等方面的内容。在对汽车空调压缩机耐久性试验要求详细分析和研究的基础上,提出了由基本耐久试验系统和计算机数据采集与处理系统组成的试验台总体设计方案。