检索结果-南通市图书馆

Acoustics Based Monitoring and Diagnostics for the Progressive Deterioration of Helical Gearboxes

Chinese Journal of Mechanical Engineering 2021年第4期34卷 98-109页

作者： Kaibo Lu james xi gu Hongwei Fan xiuquan Sun Bing Li Fengshou gu College of Mechanical and Vehicle Engineering Taiyuan University of TechnologyTaiyuan 030024China School of Engineering University of BoltonBolton BL35ABUK College of Mechanical Engineering Xi’an University of Science and TechnologyXi’an 710054China Centre for Efficiency and Performance Engineering University of HuddersfieldHuddersfield HD13DHUK. School of Industrial Automation Beijing Institute of TechnologyZhuhai 519088China

Gearbox condition monitoring(CM)plays a significant role in ensuring the operational reliability and efficiency of a wide range of critical industrial systems such as wind turbines and *** and timely diagnosis of gear faults will improve the maintenance of gearboxes operating under sub-optimal conditions,avoid excessive energy consumption and prevent avoidable damages to *** study focuses on developing CM for a multi-stage helical gearbox using airborne *** on signal phase alignments,Modulation Signal Bispectrum(MSB)analysis allows random noise and interrupting events in sound signals to be suppressed greatly and obtains nonlinear modulation features in association with gear *** coherence is evaluated for selecting the reliable bi-spectral peaks for indication of gear deterioration.A run-to-failure test of two industrial gearboxes was tested under various loading *** omnidirectional microphones were fixed near the gearboxes to sense acoustic information during *** has been shown that compared against vibration based CM,acoustics can perceive the responses of vibration in a larger areas and contains more comprehensive and stable information related to gear dynamics variation due to ***,the MSB magnitude peaks at the first three harmonic components of gear mesh and rotation components are demonstrated to be sufficient in characterizing the gradual deterioration of gear ***,the combining of MSB peaks with baseline normalization yields more accurate monitoring trends and diagnostics,allowing the gradual deterioration process and gear wear location to be represented more consistently.

关键词： Acoustics Modulation Signal Bispectrum Helical gearbox Gear wear

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

An Improved Coupled Dynamic Modelling for Exploring Gearbox Vibrations Considering Local Defects

引用

Journal of Dynamics, Monitoring and Diagnostics 2023年第4期2卷 262-274页

作者： Yaoyao Han xiaohui Chen Jiawei xiao james xi gu Minmin Xu State Key Laboratory of Mechanical Transmission Chongqing UniversityChongqingChina College of Mechanical and Vehicle Engineering Chongqing UniversityChongqingChina School of Engineering University of BoltonBoltonBL35ABUK

Gearbox is a key part in machinery,in which gear,shaft and bearing operate together to transmit motion and *** wide usage and high failure rate of gearbox make it attract much attention on its health monitoring and fault *** modelling can study the mechanism under different faults and provide theoretical foundation for fault ***,current commonly used gear dynamic model usually neglects the influence of bearing and shaft,resulting in incomplete understanding of gearbox fault diagnosis especially under the effect of local defects on gear and *** address this problem,an improved gear-shaft-bearing-housing dynamic model is proposed to reveal the vibration mechanism and responses considering shaft whirling and gear local ***,an eighteen degree-of-freedom gearbox dynamic model is proposed,taking into account the interaction among gear,bearing and ***,the dynamic model is iteratively ***,vibration responses are expounded and analysed considering gear spalling and shaft *** results show that the gear mesh frequency and its harmonics have higher amplitude through the *** RMS and the shaft rotating frequency increase with the spalling size and shaft crack angle in *** experiment is designed to verify the rationality of the proposed gearbox ***,comprehensive analysis under different spalling size and shaft crack angle are *** show that when spalling size and crack angle are larger,RMS and the amplitude of shaft rotating frequency will not increase *** dynamic model can accurately simulate the vibration of gear transmission system,which is helpful for gearbox fault diagnosis.

关键词： coupled gear-shaft-bearing-housing dynamic mode gearbox gearbox fault diagnosis local defects shaft crack

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

An Improved Dynamic Modelling for Exploring Ball Bearing Vibrations from Time-Varying Oil Film

引用

Journal of Dynamics, Monitoring and Diagnostics 2022年第2期1卷 93-102页

作者： Minmin Xu Zhenzhen Song xiaoxi Ding guoxing Li Yimin Shao james xi gu State Key Laboratory of Mechanical Transmission Chongqing UniversityChongqing 400044China College of Mechanical and Vehicle Engineering Taiyuan University of TechnologyTaiyuan 030024China School of Engineering University of BoltonBoltonBL35ABUK

Bearings are key components in rotating machinery,which is widely used in many fields,such as CNC machines,wind turbines and induction *** increasingly harsh operation environment can lead to wear and tear on raceways and reduce the precision and reliability of bearing or even *** could relieve the wear to some degree,which is benefit to prolong the bearing’s ***,investigation on the vibration responses under the influence of oil film is of great ***,for mechanism analysis,how to include the oil film into the bearing dynamic model affects the result and efficiency of *** address this problem,this study proposed a fast algorithm through load distribution and interpolation when calculating oil film stiffness and thickness during the solution of bearing vibration *** of oil film on vibration is carried out and a bearing test rig is designed to verify the proposed *** simulation result shows that rotational speed and load have vital effect on oil film and *** experimental result is consistent with the simulation,which shows that the proposed model has a better performance on modeling bearing vibration and the method of considering oil film is reasonable.

关键词： dynamic modeling fault diagnosis lubrication rolling elements bearing time-varying oil film

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Palladium-Catalzyed Atroposelective 16-Membered Macrocyclization: Total Synthesis of lsoplagiochin D

引用

Chinese Journal of Chemistry 2020年第10期38卷 1081-1085页

作者： Junwei xi Zhenhua gu Hefei National Laboratory for Physical Sciences ot the Microscale and Department of ChemistryUniversity of Science and Technology of China96 Jinzhai RoodHefeiAnhui 230026China Center for Excellence in Molecular Synthesis of CAS HefeiAnhui 230026China

Summary of main observation and conclusion Isoplagiochin D is a ring-strained macrocyclic bisbibenzylis,which showed stable axial chirality in one biaryl structure,and semistable axial chirality in the other biaryl *** reported here an unprecedented example for the catalytically asymmetric synthesis of ring-strained atropisomers via Pd-catalyzed macrocyclization between benzyl halides and *** newly developed Pd-catalyzed asym-metric macrocyclization protocol enabled us a quick synthesis of isoplagiochin D in a highly enantioselective manner.

关键词： cyclization benzyl catalyzed

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Modified bottleneck-based heuristic for large-scale job-shop scheduling problems with a single bottleneck

引用

Journal of Systems Engineering and Electronics 2007年第3期18卷 556-565页

作者： Zuo Yan gu Hanyu xi Yugeng Inst. of Automation Shanghai Jiaotong Univ. Shanghai 200240 P. R. China

A modified bottleneck-based （MB） heuristic for large-scale job-shop scheduling problems with a welldefined bottleneck is suggested, which is simpler but more tailored than the shifting bottleneck （SB） procedure. In this algorithm, the bottleneck is first scheduled optimally while the non-bottleneck machines are subordinated around the solutions of the bottleneck schedule by some effective dispatching rules. Computational results indicate that the MB heuristic can achieve a better tradeoff between solution quality and computational time compared to SB procedure for medium-size problems. Furthermore, it can obtain a good solution in a short time for large-scale jobshop scheduling problems.

关键词： job shop scheduling problem bottleneck shifting bottleneck procedure.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of Trace Addition of Ceramic on Microstructure Development and Mechanical Properties of Selective Laser Melted AlSi10Mg Alloy

引用

Chinese Journal of Mechanical Engineering 2020年第2期33卷 56-68页

作者： Yuxin Li Dongdong gu Han Zhang Lixia xi College of Materials Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 211106China

Selective laser melting(SLM)is an emerging additive manufacturing technology for fabricating aluminum alloys and aluminum matrix ***,it remains unclear how to improve the properties of laser manufactured aluminum alloy by adding ceramic reinforcing *** the effect of trace addition of TiB2 ceramic(1%weight fraction)on microstructural and mechanical properties of SLM-produced AlSi10Mg composite parts was *** densification level increased with increasing laser power and decreasing scan speed.A near fully dense composite part(99.37%)with smooth surface morphology and elevated inter-layer bonding was successfully obtained.A decrease of lattice plane distance was identified by X-ray diffraction with the laser scan speed decreased,which implied that the crystal lattices were distorted due to the dissolution of Si and TiB2 particles.A homogeneous composite microstructure with the distribution of surface-smoothened TiB2 particles was present,and a small amount of Si particles precipitated at the interface between reinforcing particles and *** contrast to the AlSi10Mg alloy,the composites showed a stabilized microhardness distribution.A higher ultimate tensile strength of 380.0 MPa,yield strength of 250.4 MPa and elongation of 3.43%were obtained even with a trace amount of ceramic *** improvement of tensile properties can be attributed to multiple mechanisms including solid solution strengthening,load-bearing strengthening and dispersion *** research provides a theoretical basis for ceramic reinforced aluminum matrix composites by additive manufacturing.

关键词： Selective laser melting TiB2 Aluminum matrix composites Mechanical properties Strengthening mechanism

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Reconfigurable manufacturing systems： Principles, design, and future trends

引用

Frontiers of Mechanical Engineering 2018年第2期13卷 121-136页

作者： Yoram KOREN xi gu Weihong guO Department of Mechanical Engineering University of Michigan Ann Arbor MI 48109 USA Department of Industrial and Systems Engineering Rutgers The State University of New Jersey Piscataway NJ 08854 USA

Reconfigurable manufacturing systems （RMSs）, which possess the advantages of both dedicated serial lines and flexible manufacturing systems, were introduced in the mid-1990s to address the challenges initiated by globalization. The principal goal of an RMS is to enhance the responsiveness of manufacturing systems to unforeseen changes in product demand. RMSs are cost- effective because they boost productivity, and increase the lifetime of the manufacturing system. Because of the many streams in which a product may be produced on an RMS, maintaining product precision in an RMS is a challenge. But the experience with RMS in the last 20 years indicates that product quality can be definitely maintained by inserting in-line inspection stations. In this paper, we formulate the design and operational principles for RMSs, and provide a state-of-the-art review of the design and operations methodologies of RMSs according to these principles. Finally, we propose future research directions, and deliberate on how recent intelligent manufacturing technologies may advance the design and operations of RMSs.

关键词： reconfigurable manufacturing systems responsiveness intelligent manufacturing

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

MODIFIED BOTTLENECK-BASED PROCEDURE FOR LARGE-SCALE FLOW-SHOP SCHEDULING PROBLEMS WITH BOTTLENECK

引用

Chinese Journal of Mechanical Engineering 2006年第3期19卷 356-361页

作者： ZUO Yan gu Hanyu xi Yugeng Institute of Automation Shanghai Jiaotong University Shanghai 200240 China

A new bottleneck-based heuristic for large-scale flow-shop scheduling problems with a bottleneck is proposed, which is simpler but more tailored than the shifting bottleneck （SB） procedure. In this algorithm, a schedule for the bottleneck machine is first constructed optimally and then the non-bottleneck machines are scheduled around the bottleneck schedule by some effective dispatching rules. Computational results show that the modified bottleneck-based procedure can achieve a tradeoff between solution quality and computational time comparing with SB procedure for medium-size problems. Furthermore it can obtain a good solution in quite short time for large-scale scheduling problems.

关键词： Flow-shop scheduling problem Heuristic Bottleneck machine

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Experimental investigations for parametric effects of dual synthetic jets on delaying stall of a thick airfoil

引用

Chinese Journal of Aeronautics 2016年第2期29卷 346-357页

作者： Zhao guoqing Zhao Qijun gu Yunsong Chen xi National Key Laboratory of Science and Technology on Rotorcraft Aeromechanics Nanjing University of Aeronauticsand Astronautics Nanjing 210016 China College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

A promising strategy of synthetic jet arrays （SJA） control for NACA0021 airfoil in preventing flow separation and delaying stall is investigated. Through aerodynamic forces, flowfield and velocity profiles measurements, it indicates that the synthetic jet （S J） could enlarge the mixing of the shear layer and then enhance the stability of boundary layer, resulting in scope reduction of the flow separation zone. Furthermore, the control effects of dual jet arrays positioned at 15%c （Actuator 1） and 40%c （Actuator 2） respectively are systematically investigated with different jet parameters, such as two typical relative phase angles and various incline angles of the jet. The jet closer to the leading edge of airfoil is more advantageous in delaying the stall of airfoil, and overall, the flow control performances of jet arrays are better than those of single actuator. At the angle of attack （AoA） just approaching and larger than the stall AoA, jet array with 180° phase difference could increase the lift coefficient more significantly and prevent flow separation. When momentum coefficient of the jet arrays is small, a larger jet angle of Actuator 2 is more effective in improving the maximum lift coefficient of airfoil. With a larger momentum coefficient of jet array, a smaller jet angle of Actuator 2 is more effective.

关键词： Active flow control Airfoil Dual synthetic jet arraysFlow separation Stall

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Interface engineering and heterometal doping Mo-NiS/Ni(OH)_(2)for overall water splitting

引用

Nano Research 2021年第10期14卷 3466-3473页

作者： Hua Zhang Baojuan xi Yu gu Weihua Chen Shenglin xiong Key Laboratory of Colloid and Interface Chemistry Ministry of EducationSchool of Chemistry and Chemical EngineeringState Key Laboratory of Crystal MaterialsShandong UniversityJinan 250100China Key Laboratory of Material Processing and Mold of Ministry of Education Zhengzhou UniversityZhengzhou 450001China

Developing cost-effective,efficient and bifunctional electrocatalysts is vital for both hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)*** catalytic activity of electrocatalysts could be optimized by reasonable electronic structure regulation and increasing active ***,we report the design and fabrication of Mo-doped nickel sulfide/hydroxide heterostructures(Mo-NiS/Ni(OH)_(2))as a multisite water splitting catalyst via straightforward solvothermal and in-situ growth *** on foreign metal doping and interface interaction,the electronic conductivity of heterostructures is improved and the charge transfer kinetics across the interface is promoted,which are demonstrated by the theoretical ***-NiS/Ni(OH)_(2)electrocatalyst is endowed with high electrocatalytic performance for water splitting and remarkable durability in alkaline *** exhibits the low overpotential of 186 and 74 mV at 10 mA·cm^(-2)for OER and HER,***,after continuously working for 50 h,the current densities of HER and OER both show negligible ***,the resulting Mo-NiS/Ni(OH)_(2)better catalyzes water splitting,yielding a current density of 10 mA·cm^(-2)at a cell voltage of 1.5 V and outperforming Pt/C-IrO2 couple(1.53 V).This result demonstrates that transition metal doping and heterogeneous interface engineering are useful means for conventional catalyst design.

关键词： heterostructure doping bifunctional catalyst overall water splitting

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：