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Effects of Unbalance Location on Dynamic Characteristics of High-speed Gasoline Engine Turbocharger with Floating Ring Bearings

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Chinese Journal of mechanical Engineering 2016年第2期29卷 271-280页

作者： WANG Longkai BIN Guangfu LI Xuejun LIU Dingqu health maintenance for mechanical Equipment key lab of hunan Province Hunan University of Science and Technology

For the high-speed gasoline engine turbocharger rotor, due to the heterogeneity of multiple parts material, manufacturing and assembly errors, running wear in impeller and uneven carbon of turbine, the random unbalance usually can be developed which will induce excessive rotor vibration, and even lead to nonlinear vibration accidents. However, the investigation of unbalance location on the nonlinear high-speed turbocharger rotordynamic characteristics is less. In order to discuss the rotor unbalance location effects of turbocharger with nonlinear floating ring bearings（FRBs）, the realistic turbocharger of gasoline engine is taken as a research object. The rotordynamic equations of motion under the condition of unbalance are derived by applied unbalance force and nonlinear oil film force of FRBs. The FE model of turbocharger rotor-bearing system is modeled which includes the unbalance excitation and nonlinear FRBs. Under the conditions of four different applied locations of unbalance, the nonlinear transient analyses are performed based on the rotor FEM. The differences of dynamic behavior are obvious to the turbocharger rotor systems for four conditions, and the bifurcation phenomena are different. From the results of waterfall and transient response analysis, the speed for the appearance of fractional frequency is not identical and the amplitude magnitude is different from the different unbalance locations, and the non-synchronous vibration does not occur in the turbocharger and the amplitude is relative stable and minimum under the condition 4. The turbocharger vibration and non-synchronous components could be reduced or suppressed by controlling the applied location of unbalance, which is helpful for the dynamic design, fault diagnosis and vibration control of the high-speed gasoline engine turbochargers.

关键词： high-speed turbocharger unbalance location nonlinear transient analysis waterfall dynamic characteristics

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Effects of Floating Ring Bearing Manufacturing Tolerance Clearances on the Dynamic Characteristics for Turbocharger

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Chinese Journal of mechanical Engineering 2015年第3期28卷 530-540页

作者： WANG Longkai BIN Guangfu LI Xuejun ZHANG Xuefeng health maintenance for mechanical Equipment key lab of hunan Province Hunan University of Science and Technology Xeca Turbo Technologies(Beijing) Co. Ltd.

The inner and outer oil film dynamic characteristic coefficients of floating ring bearings（FRBs） change due to the manufacturing tolerance of the floating ring, journal and intermediate, which leads to high-speed turbocharger＇s vibration too large and even causes nonlinear vibration accident. However, the investigation of floating ring bearing manufacturing tolerance clearance on the rotordynamic characteristics is less at present. In order to study the influence law of inner and outer clearance on turbocharger vibration, the rotor dynamic motion equations of turbocharger supported in FRBs are derived by analyzing the size relations between floating ring, journal and intermediate for the inner and outer oil film clearances, the time transient response analysis for combination of FRBs clearance are developed. A realistic turbocharger is taken as a research object, the FE model of the turbocharger with FRBs is modeled. Under the conditions of four kinds of limit state bearing clearances for inner and outer oil film, the nonlinear transient analyses are performed based on the established FE dynamic models of the nonlinear rotor-FRBs system applied incentive combinations of gravity and unbalance force, respectively. From the waterfall, the simulation results show that the speed for the appearance of fractional frequency is not identical and the amplitude magnitude is different under the four kinds of bearing manufacturing tolerance limit clearances, and fractional frequency does not appear in the turbocharger and the amplitude is minimum under the ODMin/IDMax bearing manufacturing tolerance clearances. The turbocharger vibration is reduced by controlling the manufacturing tolerance clearance combinations of FRBs, which is helpful for the dynamic design and production-manufacturing of high-speed turbocharger.

关键词： turbocharger floating ring bearing manufacturing tolerance clearance nonlinear transient analysis dynamic characteristics

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Evaluation of remaining useful life for corroded pipeline with finite element simulation and reliability theory

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Journal of Southeast University(English Edition) 2022年第1期38卷 70-76页

作者： Wang Yifei Su Chun Xie Mingjiang School of mechanical Engineering Southeast UniversityNanjing 211189China hunan provincial key lab of health maintenance for mechanical egquipment Hunan University of Science and TechnologyXiangtan 411201China

An integrated approach was proposed to evaluate the remaining useful life(RUL)of corroded petroleum *** types of failure modes(i.e.,leakage and burst failure)were considered,and the corresponding limit state functions(LSFs)were established with the structural reliability theory.A power-law function was applied to model the growth of corrosion defects,and the effect of external environmental factors on the growth of the pipeline s defect was ***,the result was compared with the commonly used linear growth *** that,a finite element simulation model was established to calculate the burst pressure of the pipeline with corrosion defects,and its accuracy was verified through hydraulic burst test and by comparison with international *** that basis,the probability that the pipeline may fail was calculated with Monte Carlo simulation(MCS)and by considering the LSFs,and the pipeline s RUL was obtained ***,sensitivity analysis was conducted to determine the sensitivity parameters for the corrosion and RUL of the *** results indicate that the radial corrosion rate,wall thickness and working pressure have a great influence on the failure probability of the ***,corresponding measures should be adopted during the operation process of the pipeline to reduce the corrosion rate and increase the wall thickness,so as to prolong the pipeline s RUL.

关键词： pipeline burst pressure finite element method remaining useful life Monte Carlo simulation

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Study on quality evaluation model in multi-station assembly processes

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Engineering Sciences 2008年第4期6卷 25-30页

作者： Wen Zejun Liu Deshun Yang Shuyi hunan provincial key lab of health maintenance for mechanical Equipment Hunan University of Science and Technology Xiangtan Hunan 411201 China School of mechanical and Electrical Engineering Central South University Changsha 410083 China

Based on features of dimension variation propagation in multi-station assembly processes,a new quality evaluation model of assembly processes is established. Firstly,the error source of multi-station assembly system is analyzed,the relationship of dimension variation propagation in multi-station assembly processes is studied and the state equation for variation propagation is constructed too. Then,the feature parameters which influence variation propagation and accumulation in multi-station assembly processes are found to evaluate quality characteristic of the assembly system. Through the derivation of equation on dimension variation propagation,station coefficient matrices which are combined and conversed to determine the max eigenvalue are educed. The max eigenvalue is multiplied by the weight coefficient to establish the quality evaluation model in multi-station assembly processes. Furthermore,assembly variation indexes are proposed to judge of the assembly technology process. Finally,through the practical example,the application of the model and assembly variation indexes are presented.

关键词： multi-station quality evaluation model variation propagation assembly variation indexes

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The Influence of the Supporting Wheel Deflection of Large-scale Rotary Kiln on Maximum Contact Stress

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工程科学（英文版） 2006年第4期4卷 92-96页

作者： Li Xuejun Qiu Weiliang Yuan Yincai Li Ping health maintenance for mechanical Equipment key lab of hunan Province Hunan Science and Technology University Xiangtan Hunan 411201 School of mechanical and Electronic Central South University Hunan Changsha 410083

The relation between the maximum contact stress ratio and deflection angle is derived from Hertz contact theory when the deflection of rotary kiln supporting wheel happens. According to the analysis of practical example, the maximum contact stress ratio within the deflection range of rotary kiln supporting wheel is listed. The contact stress will increase largely when rotary kiln supporting wheel deflects with little angle, which probably will result in accidents correlating to safety. This will provide theory conference for the design, the operating condition analysis and adjusting of the rotary kiln.

关键词：回转窑接触面应力支护水泥冶金工程

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Toughened (Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))B_(2)–SiC composites fabricated by one-step reactive sintering with a unique SiB_(6) additive

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Journal of Advanced Ceramics 2024年第1期13卷 86-100页

作者： Wei Hao Xinzhe Lu Ling Li Tao Wang Guoliang Ren Huangyue Cai Xiaofeng Zhao Dongyun Wang Na Ni Zhejiang provincial key laboratory of Urban Rail Transit Intelligent Operation and maintenance Technology&Equipment Zhejiang Normal UniversityZhejiang 321004China key lab of Education Ministry for Power Machinery and Engineering School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China

High-entropy diboride has been arousing considerable interest in recent ***,the low toughness and damage tolerance limit its applications as ultra-high-temperature structural *** we report that a unique SiB_(6) additive has been first incorporated as boron and silicon sources to fabricate a high-entropy boride(Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))B_(2)–SiC composite though one-step boro/carbothermal reduction reactive sintering.A synergetic effect of high-entropy sluggish diffusion and SiC secondary phase retarded the grain growth of the(Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))B_(2)–51SiC *** small grain size was beneficial to shorten the diffusion path for mass transport,thereby enhancing the relative density to~99.3%.These results in an increase of fracture toughness from~5.2 in HEBS-1900 to~7.7 MPa·m^(1/2) in HEBS-2000,which corresponded to a large improvement of 48%.The improvement was attributed to a mixed mode of intergranular and transgranular cracking for offering effective pinning in crack propagation,resulting from balanced grain boundary strength collectively affected by improved densification,solid solution strengthening,and incorporation of SiC secondary phase.

关键词： high-entropy diboride silicon hexaboride boro/carbothermal reduction reactive sintering fracture toughness

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Applications of Wigner high-order spectra in feature extraction of acoustic emission signals

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Engineering Sciences 2009年第3期7卷 59-65页

作者： Xiao Siwen Liao Chuanjun Li Xuejun key lab of health maintenance for mechanical Equipment of hunan Province Hunan Science and Technology University Xiangtan Hunan 411201 China Department of Precision Instruments Tsinghua University Beijing 100084 China

The characteristics of typical AE signals initiated by mechanical component damages are analyzed. Based on the extracting principle of acoustic emission(AE) signals from damaged components,the paper introduces Wigner high-order spectra to the field of feature extraction and fault diagnosis of AE signals. Some main performances of Wigner binary spectra,Wigner triple spectra and Wigner-Ville distribution (WVD) are discussed,including of time-frequency resolution,energy accumulation,reduction of crossing items and noise elimination. Wigner triple spectra is employed to the fault diagnosis of rolling bearings with AE techniques. The fault features reading from experimental data analysis are clear,accurate and intuitionistic. The validity and accuracy of Wigner high-order spectra methods proposed agree quite well with simulation results. Simulation and research results indicate that wigner high-order spectra is quite useful for condition monitoring and fault diagnosis in conjunction with AE technique,and has very important research and application values in feature extraction and faults diagnosis based on AE signals due to mechanical component damages.

关键词： acoustic emission Wigner spectra Wigner binary spectra Wigner triple spectra feature extraction rolling bearing

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Disassemblability Modeling Technology of Configurable Product Based on Disassembly Constraint Relation Weighted Design Structure Matrix(DSM)

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Chinese Journal of mechanical Engineering 2014年第3期27卷 511-519页

作者： QIU Lemiao LIU Xiaojian ZHANG Shuyou SUN Liangfeng The State key lab of Fluid Power Transmission and Control Zhejiang University

The current research of configurable product disassemblability focuses on disassemblability evaluation and disassembly sequence planning. Little work has been done on quantitative analysis of configurable product disassemblability. The disassemblability modeling technology for configurable product based on disassembly constraint relation weighted design structure matrix （DSM） is proposed. Major factors affecting the disassemblability of configurable product are analyzed, and the disassembling degrees between components in configurable product are obtained by calculating disassembly entropies such as joint type, joint quantity, disassembly path, disassembly accessibility and material compatibility. The disassembly constraint relation weighted DSM of configurable product is constructed and configuration modules are formed by matrix decomposition and tearing operations. The disassembly constraint relation in configuration modules is strong coupling, and the disassembly constraint relation between modules is weak coupling, and the disassemblability configuration model is constructed based on configuration module. Finally, taking a hydraulic forging press as an example, the decomposed weak coupling components are used as configuration modules alone, components with a strong coupling are aggregated into configuration modules, and the disassembly sequence of components inside configuration modules is optimized by tearing operation. A disassemblability configuration model of the hydraulic forging press is constructed. By researching the disassemblability modeling technology of product configuration design based on disassembly constraint relation weighted DSM, the disassembly property in maintenance, recycling and reuse of configurable product are optimized.

关键词： disassemblability modeling disassembly entropy disassembling degree weighted DSM product configuration model

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复杂机械产品多准则预防性维护设计(英文)

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2014年第11期15卷 862-872页

作者： Yi-cong GAO Yi-xiong FENG Jian-rong TAN State key lab of Fluid Power Transmission and Control Zhejiang University

研究目的:为复杂机械产品提供满足整机可靠性指标和维护成本指标的预防性维护方案多准则规划方法。创新要点:1.分析了检查、维修、更换等对复杂机械产品零部件工作寿命变化的作用机理;2.提出了复杂机械产品预防性维护多准则规划方法。... 详细信息

研究目的:为复杂机械产品提供满足整机可靠性指标和维护成本指标的预防性维护方案多准则规划方法。创新要点:1.分析了检查、维修、更换等对复杂机械产品零部件工作寿命变化的作用机理;2.提出了复杂机械产品预防性维护多准则规划方法。研究方法:1.基于非完美维修理论,建立不同模式下零件间工作寿命模型,定义维修效能因子,表征检查、维修、更换对零件寿命的影响;2.通过求解获得复杂机械产品指定时间区间的预防性维护方案,根据零部件工作寿命,采取维修和更换等预防性维护措施,减少零部件故障的发生。重要结论:零部件的预防性维护次数与其故障因子相关;机械产品尤其是复杂机械产品实施定期预防性维护能够减少或消除故障的发生。

关键词：预防性维护多准则优化工作寿命

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5-HT2A receptor-Cx43 signaling pathway participating in mirror image pain induced by scorpion sting

5-HT2A receptor-Cx43 signaling pathway participating in mirr...

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第12届生物毒素研究及医药应用学术大会

作者： Zhi-Hong Sun Hong-Ni Zhu Xiao-Xia Zhao Yu-Ying Han Cheng-Hui Cao Jiang-Bo Wang Qing-Hu Yang Yan-Heng Zhou Xia Liu Zhan-Tao Bai College of Life Sciences & Research Center for Peptide Drugs Yanan University Shaanxi Engineering & Technological Research Center for Conversation & Utilization of Regional Biological Resources Shaanxi provincial key lab of Red Dates

Serotonin(5-HT),a neuroactive substances,play an important role in the descending inhibitory and descending facilitation system.5-HT receptors,especially 5HT receptor,showed dual-directional regulation of nociceptive information,and modulated chronic *** addition,many evidences demonstrated that the 5-HT receptor(5-HT),gap junction intercellular communication,glia may participate in the regulation of pain through different molecular and cellular ***,whether their interactions are underlying or not,remains to be a necessary *** found that 5-HT antagonist significantly suppressed BmK(scorpion Buthus martensii Karsch) I-induced spontaneous pain,bilateral mechanical hypersensitivity and unilateral thermal *** pain condition,the expression of 5-HT receptor,connexin 43 and glia,showed an obvious asymmetry and variation in spinal cord and dorsal root *** addition,5-HT receptor was co-localized differentially with neuronal and glia markers and connexin ***,the gap junction hemi-channels in cultured astrocyte were opened by 5-HT,and the opening were reduced by5-HT *** indicates that the 5-HT-Cx43 signaling pathways at least in part,modulate the induction,development,maintenance and recovery of mirror image *** findings would help to elucidate the persistence,chronicalization,diversities,personalization of pain mechanisms,and further provide an effective analgesia strategy combing with 5-HTand connexins.

关键词： Serotonin 5-HT2Areceptor Connexins Mirror image pain

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