Yanhu Zhang-江苏大学机械工程学院

　　Name: Yanhu Zhang (ZHANG Yan-Hu)

　　Title: Ph. D, Associate professor, M. D supervisor

　　Address: Room No.1215, Physics and Practice Building

　　Phone: (86) 18362897956

　　Fax: (86)-511-88792058

　　E-mail: zhyh@ujs.edu.cn

Education

1. 2004/08-2008/06: B.S., School of Mechanical Engineering, North China University of Water Resources and Electric Power
2. 2008/08-2011/06: M.D., School of Mechanical Engineering, Jiangsu University,
3. 2011/09-2016/12 Ph.D., School of Mechatronics Engineering, Harbin Institute of Technology

Professional Experience

1. 2011/03-2011/08: R & D Engineer, SANY Heavy Industry Co., Ltd.
2. 2017/03-2021/07: Assistant Research Associate, Institute of Advanced Manufacturing & Modern Equipment Technology, Jiangsu University
3. 2018/08-2021/10: Post-Doctorate Research Fellowship, Electrical Engineering postdoctoral research flow station, Jiangsu University
4. 2021/07- present: Associate professor, Institute of Advanced Manufacturing & Modern Equipment Technology, Jiangsu University

Social Academic Post

1. InviteReviewerIEEE Transactions on Industrial Electronics IEEE/ASME Transactions on Mechatronics Journal of Materials Processing Technology Surface and Coatings Technology
Ceramics International
New Journal of Chemistry
Polymers for Advanced Technologies
IEEE Access
Advances in Mechanical Engineering
Journal of the Brazilian Society of Mechanical Sciences and Engineering
Materials
Machines
Lubricants
2. Members
Jiangsu Society of Mechanical Engineering-Tribology　　(M’18)
Chinese Society of Theoretical and Applied Mechanics　　(M’15)
Chinese Society of Vibration Engineering　　(M’20)
Chinese Society of Mechanical Engineering　　(SM’20)

Research Interests

1.Piezoelectric motors, including service performances and friction materials.
Ultrasonic motors (USMs) are driven by friction to translate or revolve through the micro-amplitude of a vibrating stator, which is in frictional contact with a slider or rotor. As the number of applications for USMs increases, additional demands are placed on this technology. Two key issues are the needed improvements in driving efficiency and the length of the service lifetime. At present, USM characteristics can be enhanced through optimization of the design of the stator structure, utilization of high performance of piezo-ceramic materials, compensation in the control circuit, and the use of optimized friction materials.

　　　　
(a)Designed vibration mode　　　　　　　　(b) working principle

　　　　
(c)Friction drive　　　　　　　　(d) performance enhancement

Fig. 1 Illustration issues of travelling-wave USM on principle and tribological characteristics.
Friction and wear was predetermined to affect the running process of ultrasonic motors for the intrinsic friction driving principle. Importantly, both service performance and durable lifespan are depended upon the tribological behaviors of stator and slider of linear ultrasonic motors. Specifically for linear standing-wave ultrasonic motors (SWUMs), the frictional force of the stator/slider contact interface is closely related to the output characteristics, and the wear process directly restricts the service life of the motors. In order to improve the output performance and prolong the service life of the motors, exploring the friction and wear behaviors of stator/slider contact interface has become a hypothetical issue that hinders the rapid development and application of SWUMs.

Fig. 2 Dynamic contact forces considering Coulomb friction and ultrasonic vibration.

Fig. 3 Graphically illustration of the cracking mechanism on the slider surface layer under the dynamic contact forces with considering the ultrasonic vibration.
2. Special tribology, including ultrasonic, space and cryogenic tribology.
Null.
3. Laser precision machining, surface texturing and functionalization.
Inefficient systemic loss of energy in machinery can be minimized by reduction of friction and wear in mechanical components. For example, the indispensable cogs and bearings in industrial machine are of interest, with the hope of bridging the gap between our desire for energy and adverse environmental effects. Tribology design and surface engineering technologies are sought after for improving the effectiveness and reducing friction losses in mechanical systems. Available literature indicates that surface texturing is one potential strategy to improve energy efficiency, decrease waste disposal and emissions. Textured surfaces with some intricate microstructures (pits, craters and grooves) have gained widespread acceptance in tribology because of their ability to achieve micro-hydrodynamic bearing effect, acting as reservoirs for the continuous supply of lubricants, and trapping of wear debris by eliminating or reducing plowing effects of the working surfaces.

Fig. 4 Illustration of smooth, coated, textured, and textured & coated surface and their friction characteristics.
Laser surface texturing (LST) has become an established manufacturing method owning to its advantages of been extremely fast, clean to the environment and provides excellent control on shape and size of microstructures. It has been proved that LST is valid for tribological applications in mechanical face seal, thrust bearings, cutting tools, cams/tappets, drill bit and piston rings. LST is also used for the reduction of friction (or stiction) in magnetic storage devices, minimization of wear and mechanical losses for Micro-Electro-Mechanical System (MEMS) devices. However, LST is deficient for the new challenges of improving performances of tribological systems. Importantly, it fails to timely exhibit good transitional process from boundary (and dry) lubrication to full-film lubrication or its vice-versa, though the true state of tribological system is complicated and filled with uncertainties. An important but little-known problem is the friction and wear mechanisms of textured surfaces with different lubrication regions, as well as effective measures to improve the transitional behaviour in various lubrication regimes. LST can increase the range of hydrodynamic lubrication regime in the Stribeck curve. Meanwhile, it is stated that the bulges at the edge of the dimple need to be optimized to have the positive effect of LST on lubrication regime transitions. The friction coefficient is an important parameter for tribological performance followed by wear loss, friction force, efficiency and reliability are all critical to the operation of special tribological system. In addition, it is necessary to understand the detailed wear and durability of laser textured surface for different regions and working conditions.

Fig. 5 Illustration of the laser-textured surfaces for lubrication adaptive design.

Teaching Courses

1. Piezoelectric Technology (Undergraduate course)
2. Mechanical Manufacturing Equipment Design (Undergraduate course)
3. Engineering Graphics (Undergraduate course)

Honours and Awards

1. Certificate of Reviewing, Elsevier Reviewer Recognition, 2019.05
2. High-level Innovative Talents Introduction Plan of Jiangsu Province (Jiangsu province “Double Plan”), 2018.09
3. National scholarship for doctoral students, Ministry of Education of the People's Republic of China, 2014.12
4. Best expression Award, 2013 National doctoral Academic Forum on optics and precision measurement. 2013. 12.26-12.29.

Main Research Projects

1. National Natural Science Foundation of China (51705210)
2. Jiangsu Province Post-Doctoral Research Funding Scheme (2019K195)
3. Subproject of key project of national basic research plan (Null)

Main Scientific Publications

1. Yanhu Zhang*, Yonghong Fu, Xijun Hua, Li Quan, Jianjun Qu*. Characteristics and attenuation mechanism of linear standing-wave piezoelectric motors with ceramics-mated friction couples. Tribology International, 153, 2021, 106580.
2. Zhiqiang Gong, Yanhu Zhang*, Hao Fu, Yuhua Zhou, Hongyu Liang & Jinghu Ji. Fracture behaviours of brittle ceramics under elliptical ultrasonic vibration: near-to-limit contact analysis of an elastic flat punch. International Journal of Mechanics and Materials in Design, 2021.
3. Yanhu Zhang*, Yonghong Fu, Xijun Hua, Li Quan, Jianjun Qu*. Wear debris of friction materials for linear standing-wave ultrasonic motors: Theory and experiments. Wear, 448–449, 2020, 203216.
4. Qu Yanyan, Zhang Yanhu*, Qu Jianjun*. Micro-driving behavior of carbon-fiber-reinforced epoxy resin for standing-wave ultrasonic motor. Polymer Composites. 2016, 37(7): 2152–2159.
5. Yanhu Zhang, Jianjun Qu*, Jinbang Li. Friction and wear behavior of linear standing-wave ultrasonic motors with V-shape transducers.Tribology International. 2016, 95: 95-108.

Patents

1. In-plane thin-plate longitudinal bending composite linear ultrasonic motor with small frequency difference and high efficiency, China Patent, ZL 201810064276.4.
2. A double load adjustable thrust measuring device for linear micro special motor. China Patent, ZL 201811086281.1
3. An automatic performance test system for linear micro special motor. China Patent, ZL 201811087322.9
4. A low friction cylinder for sleeve multimodal vibration caused by preloaded piezoelectric stack. China Patent, ZL 201811424294.5
5. A low friction cylinder with high frequency torsional vibration of piston rod sleeve caused by preloaded piezoelectric stack. China Patent, ZL 201811431578.7
6. A multistage parallel rotating ultrasonic motor with double output shaft. China Patent, ZL 201910559270.9
7. A preload application device for floating self-balancing ultrasonic motor. China Patent, ZL 201911266270.6
8. A parallel compound rotating ultrasonic motor with double output shaft. China Patent, ZL 201910560523.4
9. A piezoelectric energy harvesting caliper brake and its braking energy capture method. China Patent, ZL 202010128697.6

Plan for Overseas Master & Ph. D

One Master

Contact & Address

No.1215 Room, Physics and Practice Building, Jiangsu University
301 Xuefu Road, 212013 Zhenjiang, Jiangsu Province, P.R. China
Tel: 86-511-88797906
Fax: 86-511-88792058
Email: zhyh@ujs.edu.cn, tribo.zhang@gmail.com

Proverb

Life is a journey.