资源类型

期刊论文 70

会议视频 3

会议信息 1

年份

2023 8

2022 7

2021 5

2020 4

2019 7

2018 3

2017 1

2015 1

2014 2

2013 1

2012 3

2011 3

2010 6

2009 3

2008 8

2007 4

2005 1

2003 2

2002 1

2001 1

展开 ︾

关键词

信息技术 2

LMS 1

PCB缺陷检测 1

pH值 1

专家系统 1

主动视觉 1

人工智能 1

健康监测 1

光流 1

全寿命管理 1

养护 1

农业科学 1

加窗 1

动态监测 1

单波束测距 1

危险性分析 1

压电陶瓷 1

变形 1

呼吸性粉尘 1

展开 ︾

检索范围：

排序： 展示方式：

A review of nondestructive examination technology for polyethylene pipe in nuclear power plant

Jinyang ZHENG, Yue ZHANG, Dongsheng HOU, Yinkang QIN, Weican GUO, Chuck ZHANG, Jianfeng SHI

《机械工程前沿（英文）》 2018年 第13卷 第4期   页码 535-545 doi: 10.1007/s11465-018-0515-9

摘要：

Polyethylene (PE) pipe, particularly high-density polyethylene (HDPE) pipe, has been successfully utilized to transport cooling water for both non-safety- and safety-related applications in nuclear power plant (NPP). Though ASME Code Case N755, which is the first code case related to NPP HDPE pipe, requires a thorough nondestructive examination (NDE) of HDPE joints. However, no executable regulations presently exist because of the lack of a feasible NDE technique for HDPE pipe in NPP. This work presents a review of current developments in NDE technology for both HDPE pipe in NPP with a diameter of less than 400 mm and that of a larger size. For the former category, phased array ultrasonic technique is proven effective for inspecting typical defects in HDPE pipe, and is thus used in Chinese national standards GB/T 29460 and GB/T 29461. A defect-recognition technique is developed based on pattern recognition, and a safety assessment principle is summa-rized from the database of destructive testing. On the other hand, recent research and practical studies reveal that in current ultrasonic-inspection technology, the absence of effective ultrasonic inspection for large size was lack of consideration of the viscoelasticity effect of PE on acoustic wave propagation in current ultrasonic inspection techno-logy. Furthermore, main technical problems were analyzed in the paper to achieve an effective ultrasonic test method in accordance to the safety and efficiency requirements of related regulations and standards. Finally, the development trend and challenges of NDE test technology for HDPE in NPP are discussed.

关键词： polyethylene pipe     nuclear power plant     ultrasonic inspection     nondestructive testing     safety assessment    

HTML PDF 收藏

density measurement for plastic injection molding via ultrasonic technology

《机械工程前沿（英文）》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0714-2

摘要： Density variation during the injection molding process directly reflects the state of plastic melt and contains valuable information for process monitoring and optimization. Therefore, in-situ density measurement is of great interest and has significant application value. The existing methods, such as pressure−volume−temperature (PVT) method, have the shortages of time-delay and high cost of sensors. This study is the first to propose an in-situ density measurement method using ultrasonic technology. The analyses of the time-domain and frequency-domain signals are combined in the proposed method. The ultrasonic velocity is obtained from the time-domain signals, and the acoustic impedance is computed through a full-spectral analysis of the frequency-domain signals. Experiments with different process conditions are conducted, including different melt temperature, injection speed, material, and mold structure. Results show that the proposed method has good agreement with the PVT method. The proposed method has the advantages of in-situ measurement, non-destructive, high accuracy, low cost, and is of great application value for the injection molding industry.

关键词： ultrasonic measurement     melt density     in-situ measurement     injection molding    

HTML PDF 收藏

Linear ultrasonic motor using quadrate plate transducer

Jiamei JIN, Chunsheng ZHAO

《机械工程前沿（英文）》 2009年 第4卷 第1期   页码 88-91 doi: 10.1007/s11465-009-0016-y

摘要： A linear ultrasonic motor using a quadrate plate transducer was developed for precision positioning. This motor consists of two pairs of Pb(Zr,Ti)O piezoelectric ceramic elements, which are piezoelectrically excited into the second-bending mode of the motor stator’s neutral surface in two orthogonal directions, on which the tops of four projections move along an elliptical trajectory, which in turn drives a contacted slider into linear motion via frictional forces. The coincident frequency of the stator is easily obtained for its coincident characteristic dimension in two orthogonal directions. The performance characteristics achieved by the motor are: 1) a maximum linear speed of more than 60 mm/s; 2) a stroke of more than150 mm; 3) a driving force of more than 5.0 N; and 4) a response time of about 2 ms.

关键词： ultrasonic motor     quadrate plate     coincident frequency     alternant contact    

HTML PDF 收藏

Postprocessor development for ultrasonic cutting of honeycomb core curved surface with a straight blade

《机械工程前沿（英文）》 2023年 第18卷 第1期 doi: 10.1007/s11465-022-0729-8

摘要： When ultrasonically cutting honeycomb core curved parts, the tool face of the straight blade must be along the curved surface’s tangent direction at all times to ensure high-quality machining of the curved surface. However, given that the straight blade is a nonstandard tool, the existing computer-aided manufacturing technology cannot directly realize the above action requirement. To solve this problem, this paper proposed an algorithm for extracting a straight blade real-time tool face vector from a 5-axis milling automatically programmed tool location file, which can realize the tool location point and tool axis vector conversion from the flat end mill to the straight blade. At the same time, for the multi-solution problem of the rotation axis, the dependent axis rotation minimization algorithm was introduced, and the spindle rotation algorithm was proposed for the tool edge orientation problem when the straight blade is used to machine the curved part. Finally, on the basis of the MATLAB platform, the dependent axis rotation minimization algorithm and spindle rotation algorithm were integrated and compiled, and the straight blade ultrasonic cutting honeycomb core postprocessor was then developed. The model of the machine tool and the definition of the straight blade were conducted in the VERICUT simulation software, and the simulation machining of the equivalent entity of the honeycomb core can then be realized. The correctness of the numerical control program generated by the postprocessor was verified by machining and accuracy testing of the two designed features. Observation and analysis of the simulation and experiment indicate that the tool pose is the same under each working condition, and the workpieces obtained by machining also meet the corresponding accuracy requirements. Therefore, the postprocessor developed in this paper can be well adapted to the honeycomb core ultrasonic cutting machine tool and realize high-quality and high-efficient machining of honeycomb core composites.

关键词： honeycomb core     straight blade     ultrasonic cutting     tool pose     postprocessor    

HTML PDF 收藏

Vibration characteristics and machining performance of a novel perforated ultrasonic vibration platform

《机械工程前沿（英文）》 2023年 第18卷 第1期 doi: 10.1007/s11465-022-0730-2

摘要： Ultrasonic vibration-assisted grinding (UVAG) is an advanced hybrid process for the precision machining of difficult-to-cut materials. The resonator is a critical part of the UVAG system. Its performance considerably influences the vibration amplitude and resonant frequency. In this work, a novel perforated ultrasonic vibration platform resonator was developed for UVAG. The holes were evenly arranged at the top and side surfaces of the vibration platform to improve the vibration characteristics. A modified apparent elasticity method (AEM) was proposed to reveal the influence of holes on the vibration mode. The performance of the vibration platform was evaluated by the vibration tests and UVAG experiments of particulate-reinforced titanium matrix composites. Results indicate that the reasonable distribution of holes helps improve the resonant frequency and vibration mode. The modified AEM, the finite element method, and the vibration tests show a high degree of consistency for developing the perforated ultrasonic vibration platform with a maximum frequency error of 3%. The employment of ultrasonic vibration reduces the grinding force by 36% at most, thereby decreasing the machined surface defects, such as voids, cracks, and burnout.

关键词： ultrasonic vibration-assisted grinding     perforated ultrasonic vibration platform     vibration characteristics     apparent elasticity method     grinding force     surface integrity    

HTML PDF 收藏

Design of ultrasonic elliptical vibration cutting system for tungsten heavy alloy

《机械工程前沿（英文）》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0715-1

摘要： Nanoscale surface roughness of tungsten heavy alloy components is required in the nuclear industry and precision instruments. In this study, a high-performance ultrasonic elliptical vibration cutting (UEVC) system is developed to solve the precision machining problem of tungsten heavy alloy. A new design method of stepped bending vibration horn based on Timoshenko’s theory is first proposed, and its design process is greatly simplified. The arrangement and working principle of piezoelectric transducers on the ultrasonic vibrator using the fifth resonant mode of bending are analyzed to realize the dual-bending vibration modes. A cutting tool is installed at the end of the ultrasonic vibration unit to output the ultrasonic elliptical vibration locus, which is verified by finite element method. The vibration unit can display different three-degree-of-freedom (3-DOF) UEVC characteristics by adjusting the corresponding position of the unit and workpiece. A dual-channel ultrasonic power supply is developed to excite the ultrasonic vibration unit, which makes the UEVC system present the resonant frequency of 41 kHz and the maximum amplitude of 14.2 μm. Different microtopography and surface roughness are obtained by the cutting experiments of tungsten heavy alloy hemispherical workpiece with the UEVC system, which validates the proposed design’s technical capability and provides optimization basis for further improving the machining quality of the curved surface components of tungsten heavy alloy.

关键词： tungsten heavy alloy     ultrasonic elliptical vibration cutting     Timoshenko’s theory     resonant mode of bending     finite element method    

HTML PDF 收藏

视觉检测技术及应用

叶声华,邾继贵,王仲,杨学友

《中国工程科学》 1999年 第1卷 第1期   页码 49-52

摘要：

视觉检测技术，尤其是基于三角法的主动和被动视觉检测技术具有非接触、速度快、柔性好等特点，是一种先进的检测手段，适合现代制造业的需要。文章论述了视觉检测技术原理，讨论了已经研制的多个实际视觉检测系统，从不同角度展示了视觉检测技术在现代制造业中广阔的应用前景。

关键词： 主动视觉     被动视觉     检测系统     现代制造    

HTML PDF 收藏

中医舌诊客观化研究

翁维良,黄世敬

《中国工程科学》 2001年 第3卷 第1期   页码 78-82

摘要：

中国中医研究院西苑医院等运用计算机图像处理技术，结合中医舌诊相关理论研制出“中医舌诊专家系统”，实现了舌诊的定量分析。我们应用该系统，对927例患者舌质舌苔定量观察，探讨舌诊定量变化规律，结果表明，各类舌质舌苔有相应的RGB（R为红色，G为绿色，B为蓝色）数量特征（P<0.01）;舌苔RGB值不仅与舌苔颜色密切相关，而且和舌苔的厚薄、腐腻等变化明显相关；舌苔面积百分数基本上反映了舌苔的覆盖面积。因此，应用中医舌诊专家系统对舌质舌苔进行量化诊断，可为中医辨证提供客观依据。

关键词： 舌诊     客观化     专家系统    

HTML PDF 收藏

Improving the performances of ultrasonic motors using intermittent contact scheme

Jiamei JIN, Jianhui ZHANG, Fu QIAN, Zhenfeng PAN,

《机械工程前沿（英文）》 2010年 第5卷 第2期   页码 242-246 doi: 10.1007/s11465-010-0016-y

摘要： Most ultrasonic motors operate in intermittent contact scheme. Their stators drive the rotors (or sliders) when the stators contact the rotors, and the rotors (or sliders) move under an inertia force when the stators and the rotors are separated. The duty cycle of the contact and the “flight” manages motors’ output performance. To obtain a large output force or output velocity, this paper proposes a concept using the alternative work of a multi-stator or the multi-driving end of a single stator. The method can avoid larger noise, poor efficiency, and lifetime of motors. A novel linear ultrasonic motor using the alternative work of the multi-driving end of a single stator was fabricated and investigated experimentally. The traveling speed without load of the slider is 88 mm/s, and the maximum load is 0.32 N.

关键词： ultrasonic motor     intermittent contact     alternative work    

HTML PDF 收藏

Investigation on a cylindrical ultrasonic micromotor

ZHU Hua, CHEN Chao, ZHAO Chunsheng

《机械工程前沿（英文）》 2007年 第2卷 第4期   页码 394-398 doi: 10.1007/s11465-007-0068-9

摘要： The relationship between the arrangement of ceramics and the force coefficient shows that the maximum excitation efficiency will be obtained when the ceramics are placed at the trough of the first bending mode of the stator. Therefore, a cylindrical ultrasonic micromotor with a novel stator is proposed. The prototype motor is 5 mm in diameter, 30 mm in length and 4.2 g in weight. The micromotor operates with the first bending mode at 53 kHz. Its maximum speed is 350 r/min when the drive voltage is 200 V and the stall torque reaches 2.5 mN · m. As this motor is suitable for miniaturization because of its simple structure, another cylindrical ultrasonic micromotor is developed. Piezoelectric ceramic tube is used as its stator. This micromtor is 2 mm in diameter, 7 mm in length and 0.258 g in weight. Its speed reaches 813 r/min when the drive voltage is 60 V at 75 kHz. The operation mechanism, structure and design method of these two motors are introduced.

关键词： coefficient     bending     kHz     suitable     weight    

HTML PDF 收藏

Machinability of ultrasonic vibration-assisted micro-grinding in biological bone using nanolubricant

《机械工程前沿（英文）》 2023年 第18卷 第1期 doi: 10.1007/s11465-022-0717-z

摘要： Bone grinding is an essential and vital procedure in most surgical operations. Currently, the insufficient cooling capacity of dry grinding, poor visibility of drip irrigation surgery area, and large grinding force leading to high grinding temperature are the technical bottlenecks of micro-grinding. A new micro-grinding process called ultrasonic vibration-assisted nanoparticle jet mist cooling (U-NJMC) is innovatively proposed to solve the technical problem. It combines the advantages of ultrasonic vibration (UV) and nanoparticle jet mist cooling (NJMC). Notwithstanding, the combined effect of multi parameter collaborative of U-NJMC on cooling has not been investigated. The grinding force, friction coefficient, specific grinding energy, and grinding temperature under dry, drip irrigation, UV, minimum quantity lubrication (MQL), NJMC, and U-NJMC micro-grinding were compared and analyzed. Results showed that the minimum normal grinding force and tangential grinding force of U-NJMC micro-grinding were 1.39 and 0.32 N, which were 75.1% and 82.9% less than those in dry grinding, respectively. The minimum friction coefficient and specific grinding energy were achieved using U-NJMC. Compared with dry, drip, UV, MQL, and NJMC grinding, the friction coefficient of U-NJMC was decreased by 31.3%, 17.0%, 19.0%, 9.8%, and 12.5%, respectively, and the specific grinding energy was decreased by 83.0%, 72.7%, 77.8%, 52.3%, and 64.7%, respectively. Compared with UV or NJMC alone, the grinding temperature of U-NJMC was decreased by 33.5% and 10.0%, respectively. These results showed that U-NJMC provides a novel approach for clinical surgical micro-grinding of biological bone.

关键词： micro-grinding     biological bone     ultrasonic vibration (UV)     nanoparticle jet mist cooling (NJMC)     grinding force     grinding temperature    

HTML PDF 收藏

Effects of inclination angles of disc cutter on machining quality of Nomex honeycomb core in ultrasonic

Yidan WANG, Renke KANG, Yan QIN, Qian MENG, Zhigang DONG

《机械工程前沿（英文）》 2021年 第16卷 第2期   页码 285-297 doi: 10.1007/s11465-021-0631-9

摘要： Ultrasonic cutting with a disc cutter is an advanced machining method for the high-quality processing of Nomex honeycomb core. The machining quality is influenced by ultrasonic cutting parameters, as well as tool orientations, which are determined by the multi-axis machining requirements and the angle control of the cutting system. However, in existing research, the effect of the disc cutter orientation on the machining quality has not been studied in depth, and practical guidance for the use of disc cutters is lacking. In this work, the inclined ultrasonic cutting process with a disc cutter was analyzed, and cutting experiments with different inclination angles were conducted. The theoretical residual height models of the honeycomb core, as a result of the lead and tilt angles, were established and verified with the results obtained by a linear laser displacement sensor. Research shows that the residual height of the honeycomb core, as a result of the tilt angle, is much larger than that as a result of the lead angle. Furthermore, the tearing of the cell wall on the machined surface was observed, and the effects of the ultrasonic vibration, lead angle, and tilt angle on the tear rate and tear length of the cell wall were studied. Experimental results revealed that ultrasonic vibration can effectively decrease the tearing of the cell wall and improve the machining quality. Changes in the tilt angle have less effect than changes in the lead angle on the tearing of the cell wall. The determination of inclination angles should consider the actual processing requirements for the residual height and the machining quality of the cell wall. This study investigates the influence of the inclination angles of a disc cutter on the machining quality of Nomex honeycomb core in ultrasonic cutting and provides guidelines for machining.

关键词： Nomex honeycomb core     disc cutter     inclined ultrasonic cutting     machining quality    

HTML PDF 收藏

QMS: Its Application and Innovation at a Small Inspection and Appraisal Company

Ai-lian Lin,Yong-ning Niu,Ping-jing Yu

《工程管理前沿（英文）》 2014年 第1卷 第4期   页码 390-394 doi: 10.15302/J-FEM-2014054

摘要： This paper analyzes the experience of a small inspection and appraisal company, discusses the establishment of the criteria and principles of a quality management system (QMS), explores how to appropriately use the articles of the relevant regulations and laws and how to foster innovation in quality management, and finally, makes an evaluation of QMS improvement and its contribution to the development of quality management companies.

关键词： buildings     inspection-appraisal     quality management system (QMS)    

HTML PDF 收藏

Performance investigation on ultrasonic levitation axial bearing for flywheel storage system

Taijiang PENG, Zhigang YANG, Junwu KAN, Fengjun TIAN, Xiaohong CHE,

《机械工程前沿（英文）》 2009年 第4卷 第4期   页码 415-419 doi: 10.1007/s11465-009-0051-8

摘要： The bearing is an important basic mechanical part for supporting a shaft. A flywheel storage system needs a type of noncontact support bearing to enhance the speed of the axis. A magnetic suspension bearing is one type of noncontact bearing but has electromagnetic interference to other electric equipment. Based on the performance research of ultrasonic levitation technology, a novel noncontact bearing called ultrasonic bearing is presented, which consists of a special piezoelectric vibrator supporting the load. Experiments are carried out to study the relationships among the amplitude of the vibrator and levitation clearance, the highest speed of the axis, and the frictional moment of the axis. Results show that the levitation clearance becomes smaller gradually with increasing load; the rotation speed is up to 8946 r/min, and the friction moment is only 2.095×10 N·m when the levitation clearance is 8.53 μm. The ultrasonic bearing is highlighted because of its simple structure, strong levitation ability, and low friction moment.

关键词： ultrasonic bearing     flywheel storage system     piezoelectric ceramic     piezoelectric vibrator    

HTML PDF 收藏

Analysis and control of micro-stepping characteristics of ultrasonic motor

Ning CHEN, Jieji ZHENG, Xianliang JIANG, Shixun FAN, Dapeng FAN

《机械工程前沿（英文）》 2020年 第15卷 第4期   页码 585-599 doi: 10.1007/s11465-019-0577-3

摘要： Micro-stepping motion of ultrasonic motors satisfies biomedical applications, such as cell operation and nuclear magnetic resonance, which require a precise compact-structure non-magnetization positioning device. When the pulse number is relatively small, the stopping characteristics have a non-negligible effect on the entire stepwise process. However, few studies have been conducted to show the rule of the open-loop stepwise motion, especially the shutdown stage. In this study, the modal differences of the shutdown stage are found connected with amplitude and velocity at the turn-off instant. Changes of the length in the contact area and driving zone as well as the input currents, vibration states, output torque, and axial pressure are derived by a simulation model to further explore the rules. The speed curves and vibration results in functions of different pulse numbers are compared, and the stepwise motion can be described by a two-stage two-order transfer function. A test workbench based on the Field Programmable Gate Array is built for acquiring the speed, currents, and feedback voltages of the startup–shutdown stage accurately with the help of its excellent synchronization performances. Therefore, stator vibration, rotor velocity, and terminal displacements under different pulse numbers can be compared. Moreover, the two-stage two-order model is identified on the stepwise speed curves, and the fitness over 85% between the simulation and test verifies the model availability. Finally, with the optimization of the pulse number, the motor achieves 3.3 µrad in clockwise and counterclockwise direction.

关键词： ultrasonic motor     stepping characteristics     pulse number control     synchronous acquisition system     precise positioning    

HTML PDF 收藏

标题 作者 时间 类型 操作

A review of nondestructive examination technology for polyethylene pipe in nuclear power plant

Jinyang ZHENG, Yue ZHANG, Dongsheng HOU, Yinkang QIN, Weican GUO, Chuck ZHANG, Jianfeng SHI

期刊论文

density measurement for plastic injection molding via ultrasonic technology

期刊论文

Linear ultrasonic motor using quadrate plate transducer

Jiamei JIN, Chunsheng ZHAO

期刊论文

Postprocessor development for ultrasonic cutting of honeycomb core curved surface with a straight blade

期刊论文

Vibration characteristics and machining performance of a novel perforated ultrasonic vibration platform

期刊论文

Design of ultrasonic elliptical vibration cutting system for tungsten heavy alloy

期刊论文

视觉检测技术及应用

叶声华,邾继贵,王仲,杨学友

期刊论文

中医舌诊客观化研究

翁维良,黄世敬

期刊论文

Improving the performances of ultrasonic motors using intermittent contact scheme

Jiamei JIN, Jianhui ZHANG, Fu QIAN, Zhenfeng PAN,

期刊论文

Investigation on a cylindrical ultrasonic micromotor

ZHU Hua, CHEN Chao, ZHAO Chunsheng

期刊论文

Machinability of ultrasonic vibration-assisted micro-grinding in biological bone using nanolubricant

期刊论文

Effects of inclination angles of disc cutter on machining quality of Nomex honeycomb core in ultrasonic

Yidan WANG, Renke KANG, Yan QIN, Qian MENG, Zhigang DONG

期刊论文

QMS: Its Application and Innovation at a Small Inspection and Appraisal Company

Ai-lian Lin,Yong-ning Niu,Ping-jing Yu

期刊论文

Performance investigation on ultrasonic levitation axial bearing for flywheel storage system

Taijiang PENG, Zhigang YANG, Junwu KAN, Fengjun TIAN, Xiaohong CHE,

期刊论文

Analysis and control of micro-stepping characteristics of ultrasonic motor

Ning CHEN, Jieji ZHENG, Xianliang JIANG, Shixun FAN, Dapeng FAN

期刊论文