检索结果-南通市图书馆

Material analysis of the fatigue mechanism of rollers in tapered roller bearings

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2018年第7期61卷 1003-1011页

作者： GUO Wei cao hongrui ZI YanYang HE ZhengJia State Key Laboratory for Manufacturing Systems Engineering Xi'an Jiaotong University

Rolling contact fatigue is the main failure mechanism of tapered roller bearings. This study investigated the fatigue mechanism of rollers in a tapered roller bearing that failed in a run-to-failure test. Roller microstructure and crack morphology were investigated through scanning electron microscopy. A microhardness test was performed to investigate the strain hardening of the roller material induced by rolling contact fatigue. Results showed that microcavities and holes are important influential factors of crack initiation and propagation. Crack propagation angle affects crack morphology and propagation mode. Material strain hardening accelerates crack growth. Furthermore, roller misalignment causes uneven hardenability and severe damage to roller ends.

关键词： rolling contact fatigue mechanism crack propagation material microstructure roller misalignment

A novel method for vibration signal transmission and attenuation analysis in complex planetary gearboxes

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第9期67卷 2939-2953页

作者： WEI ChaoHu cao hongrui SHI JiangHai YANG Yang DU MingGang National and Local Joint Engineering Research Center of Equipment Operation Safety and Intelligent Monitoring Xi’an Jiaotong UniversityXi’an 710049China School of Mechanical Engineering Xi’an Jiaotong UniversityXi’an 710049China China North Vehicle Research Institute Beijing 100072China

Planetary gearboxes play a crucial role in altering rotary speed and transmitting power in large machines like wind turbines and sophisticated vehicles. There are many nonlinear interfaces, such as splines, bearings, and gear pairs, in planetary gearboxes, and the resulting vibration signal transmission and attenuation mechanisms are still unknown. In this study, a novel method for quantitatively analyzing the transmission and attenuation of vibration signals is proposed. A multibody dynamic model of the planetary gearbox considering nonlinear gear meshing is presented and experimentally validated. To avoid the interference of foundation vibration on the transmission of the fault signal, the fault impact factor(FIF) is used to describe the intensity of the failure, which aligns well with the experimental signals. Based on the FIF, the vibration signal attenuation of nonlinear interfaces such as splines, bearings, and gear meshing interfaces is quantitatively evaluated. To clarify the transfer paths of fault vibration signals inside the gearbox, the transfer path area method(TPAM) based on FIF is proposed. According to the simulated results,the primary transfer paths of fault vibration signals within the gearbox have been identified, which is of great help in understanding the transmission and attenuation of vibration signals in planetary gearboxes.

关键词： planetary gearbox nonlinear interface fault mechanism vibration transmission vibration attenuation

A data-driven threshold for wavelet sliding window denoising in mechanical fault detection

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2014年第3期57卷 589-597页

作者： CHEN YiMin ZI YanYang cao hongrui HE ZhengJia SUN HaiLiang School of Mechanical Engineering State Key Laboratory for Manufacturing and Systems Engineering Xi'an Jiaotong University Beijing Institute of Astronautical Systems Engineering

Wavelet denoising is an effective approach to extract fault features from strong background *** has been widely used in mechanical fault detection and shown excellent ***,traditional thresholds are not suitable for nonstationary signal denoising because they set universal thresholds for different wavelet ***,a data-driven threshold strategy is proposed in this ***,the signal is decomposed into different subbands by wavelet *** a data-driven threshold is derived by estimating the noise power spectral density in different *** the data-driven threshold is dependent on the noise estimation and adapted to data,it is more robust and accurate for denoising than traditional ***,sliding window method is adopted to set a flexible local *** this method was applied to simulation signal and an inner race fault diagnostic case of dedusting fan bearing,the proposed method has good result and provides valuable advantages over traditional methods in the fault detection of rotating machines.

关键词： wavelet denoising data-driven threshold noise estimation bearing fault diagnosis

The principle of second generation wavelet for milling cutter breakage detection

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2009年第5期52卷 1312-1322页

作者： HE ZhengJia cao hongrui LI Zhen ZI YanYang CHEN XueFeng State Key Laboratory for Manufacturing Systems Engineering School of Mechanical EngineeringXi’an Jiaotong UniversityXi’an 710049China

Performance degradation or failure of manufacturing equipment will badly influence machining *** of discontinuousness of the milling process,dynamic signals produced in the milling process become *** paper indicates that the essence of SGW(second generation wavelet) transform in non-stationary signal processing is the mathematics principle of inner product transform of a dynamic signal with basis ***,by means of the inner product operation of a signal with basis functions containing scale function and wavelet function,signal decomposition and reconstruction are *** emission signals generated in the milling processes of a CNC machine were analyzed by using the basis functions of SGW which are oscillation,decay and compact *** features of end milling cutter breakage have been extracted,and the influences on machining surface quality have been identified effectively,which provide scientific bases for fault diagnosis,error tracing and quality control.

关键词： SGW inner product algorithm cutter breakage machining quality

Neutronic analysis of ITER radial x-ray camera

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2019年第2期21卷 105-112页

作者： Luying NIU hongrui cao Kun XU Liqun HU Institute of Plasma Physics Chinese Academy of Sciences

The radial x-ray camera(RXC) is designed to measure the poloidal profile of plasma x-ray emission with high spatial and temporal resolution. The RXC diagnostic system consists of internal camera module and external camera module that view the core region and outer region through the vertical slots of the diagnostic first wall and diagnostics shield module of the equatorial port plug. To ensure the normal performance of the silicon photodiode array detectors of the cameras in the hard neutron irradiation environment in ITER tokamak, it is necessary to calculate neutron flux, radiation damage and the nuclear heating of the silicon photodiode array detectors and simulate the radiation maps of the range of RXC. This work estimated the nuclear environment of RXC based on Monte Carlo N-particle transport code, plasma scenarios of ITER tokamak and the RXC-integrated ITER CLITE model. The neutron flux of silicon photodiode array detectors and the lifetime of the silicon photodiode detector in the camera were calculated. The neutronic analysis results show that the shielding design has achieved the effect as expected and is able to guarantee the normal work of the detector during the ITER deuterium–deuterium phase without replacement, three detectors of the external camera can be operated during the whole deuterium–tritium phase without replacement.

关键词： tokamak radial x-ray camera neutronic

Dynamic linear calibration method for a wide range neutron flux monitor system in ITER

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2013年第4期24卷 57-60页

作者： LI Shiping XU Xiufeng cao hongrui YANG Qingwei YIN Zejie State Key Laboratory of Particle Detection and Electronics University of Science andTechnology of China Department of Modern Physics University of Science and Technology of China Southwestern Institute of Physics

As a key part of the diagnosis system in the International Thermonuclear Experimental Reactor(ITER),the neutron flux monitor(NFM),which measures the neutron intensity of the fusion reaction,is a Counting-Campbelling system with a large dynamic counting range.A dynamic linear calibration method is proposed in this paper to solve the problem of cross-over between the different counting and Campbelling channels,and improve the accuracy of the cross-calibration for long-term *** experimental results show that the NFM system with the dynamic linear calibration system can obtain the neutron flux of the fusion reactor in real time and realize the seamless measurement area connection between the two channels.

关键词：动态非线性监测系统中子通量校正方法 ITER 国际热核实验反应堆聚变反应堆组成部分

Simulation and calibration of the response function of multi-sphere neutron spectrometer

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2013年第6期24卷 105-108页

作者： JIANG Xiaofei CHEN Chao cao Jing cao hongrui LI Shiping SONG Xianying YIN Zejie State Key Laboratory of Particle Detection and Electronics University of Science and Technology of China Department of Modern Physics University of Science and Technology of China Southwestern Institute of Physics

In order to realize the on-line real-time measurement of neutron spectrum of ITER fusion,this paper presents a multi-sphere spectrometer system which consists of eight thermal neutron detectors,namely SP9 3He proportional counter,embedded in eight different diameter polyethylene *** response function of eight polyethylene spheres of multi-sphere neutron spectrometer was calculated after the simulation of the neutron transport processes in multi-sphere spectrometer by adopting software *** peak of the response function is in the low energy region for smaller diameter polyethylene *** the polyethylene sphere diameter increased,the peak of the response function moves to the high energy *** experimental calibration adopts 241Am-Be neutron *** relative error between normalized data of experiment 4πsolid angle counts and normalized data of simulated detection efficiency of 4in to 8in polyethylene sphere is from 1.152%to 12.222%.The experimental results verify the response function of the *** these results provide a theoretical and experimental basis for solving the on-line real-time neutron spectrum of ITER fusion.

关键词：响应函数中子谱仪仿真在线实时测量正比计数管数据归一化校准 Geant4

An automatic gain adjustment Campbell integrator for neutron flux detection in ITER

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2012年第2期23卷 114-117页

作者： cao hongrui LI Shiping XU Xiufeng TANG Shibiao YANG Jinwei YANG Qingwei YIN Zejie State Key Lab Particle Detect&Elect University of Science and Technology of ChinaHefei 230026China Southwestern Institute of Physics Chengdu 610041China

Neutron Flux Monitor, a key diagnostic system in International Thermonuclear Experimental Reactor, may provide for reading a series of important parameters in fusion reaction process. We designed an important part of its main electronic system - Automatic Gain Adjustment Campbell Integrator (AGACI), expanding the detecting neutron counting rate of 104-108 cps (counts per second). The total gain of AGACI in five files is divided into 1, 10, 100, 1000, and 10 000 times, and can be automatically adjusted. The linear correlation coefficient (R) is more than 0.9999 in AGACI working range.

关键词：增益调整中子通量 ITER 贝尔检测国际热核实验反应堆积分线性相关系数

在线全文

学校读者我要写书评

暂无评论

切削工况下机床主轴回转精度动态预测方法

机械工程学报 2020年第17期56卷 240-248页

作者：康婷曹宏瑞西安交通大学机械工程学院西安710049 西安交通大学机械制造系统工程国家重点实验室西安710049

回转精度是衡量主轴加工性能的重要指标。现有的回转精度测量方法通常借助标准球并在空转条件下进行,无法计入切削载荷等负载带来的影响,难以反映主轴在切削状态下的真实精度。针对该问题,提出一种基于动力学模型的主轴回转精度动态预... 详细信息

回转精度是衡量主轴加工性能的重要指标。现有的回转精度测量方法通常借助标准球并在空转条件下进行,无法计入切削载荷等负载带来的影响,难以反映主轴在切削状态下的真实精度。针对该问题,提出一种基于动力学模型的主轴回转精度动态预测方法。首先建立高保真的高速主轴-轴承系统动力学模型,并将切削力等激励载荷作为输入边界条件。然后利用测力仪测量、修正切削力,并将其输入动力学模型,实现主轴振动响应和径向回转误差的动态预测。设计并制作一套主轴回转误差在线测量装置,对回转精度预测结果进行试验验证。将不同切削工况下的仿真与试验结果进行对比分析,结果表明提出的方法能够准确预测主轴回转精度的变化规律,可以为主轴加工性能评估提供依据。

关键词：回转精度机床主轴动力学建模切削工况动态预测