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force Parameter Model of 3-Roll Mills for Continuous Cold Rolling Wires

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International Journal of Minerals,Metallurgy and Materials 1999年第4期13卷 292-295页

作者： Baolong Zheng1 Li Sun2 Ruichen An2 Jin Wang1 Weichang Zhu1(l Material Science and Engineering School, University of Science and Technology Beijing, Beijing 100083, China2 Tangshan iron and Steel Co. Ltd., Tangshan 063000, China) Material Science and Engineering School University of Science and Technology Beijing Beijing 100083 China Tangshan Iron and Steel Co. Ltd. Tangshan 063000 China

Based on experimental data, the mathematical model of rolling force parameters of 3-roll mills was studied. The structure ofthe model was theoretically set up and the coefficients were determined by static analysis of the data. The torque in continuous rollingwas measured, and the characteristics and efficiency of 3-roll mills are investigated.

关键词： 3-roll mill force mathematical model cold rolling wire

force/Moment Isotropy of 8/4-4 Parallel Six-Axis force Sensor Based on Performance Atlases

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Transactions of Nanjing University of Aeronautics and Astronautics 2018年第6期35卷 1018-1026页

作者： Song Weishan Li Chenggang Wang Chunming Song Yong Wu Zefeng Rajnathsing Hemant College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and Astronautics

A six-axis force sensor with parallel 8/4-4 structure is introduced and its measurement principle is *** on condition numbers of Jacobian matrix spectral norm of the sensor,the relationship between the force and moment isotropy and some structural parameters is *** test methods are used to determine the degree of primary and secondary factors that have significant effect on sensor ***,the relationship between each performance index and the structural parameters of the sensor is analyzed by the method of the atlas,which lays a foundation for structural optimization design of the force sensor.

关键词： six-axis force sensor Jacobian matrix condition number isotropy orthogonal test indices atlases

A force-closure test for soft multi-fingered grasps

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Science China(Technological Sciences) 1998年第1期41卷 62-69页

作者：左炳然钱文瀚 Research Institute of Robotics Shanghai Jiao Tong University Shanghai China

This paper deals with the problem of force-closure analysis for soft multi-fingered grasps. The first step is the study of the relationship between the external wrench space and the manipulation force space at any contact. Constraint force set, strictly constraint force set and normal force set are defined in the contact force space, followed by an investigation of their relationships. Based on the convexity of the friction constraints for soft finger contact, the necessary and sufficient conditions for force-closure grasps are derived. Accordingly an efficient algorithm for testing force-closure is presented. Some illustrative examples are given.

关键词： soft multi-fingered grasps force-closure constraint force set strictly constraint force set normal force set.

Characterizing and controlling infrared phonon anomaly of bilayer graphene in optical-electrical force nanoscopy

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Light(Science & Applications) 2023年第12期12卷 2700-2710页

作者： Junghoon Jahng Sunho Lee Seong-Gu Hong Chang Jun Lee Sergey G.Menabde Min Seok Jang Dong-Hyun Kim Jangyup Son Eun Seong Lee Hyperspectral Nano-imaging Team Korea Research Institute of Standards and ScienceDaejeon 34113Republic of Korea Department of Aerospace Engineering University of Illinois at Urbana-ChampaignUrbanaIL 61801USA Multiscale Mechanical Properties Measurement Team Korea Research Institute of Standards and ScienceDaejeon 34113Republic of Korea School of Mechanical Engineering Chonnam National UniversityGwangju 61186Republic of Korea School of Electrical Engineering Korea Advanced Institute of Science and TechnologyDaejeon 34141Republic of Korea Functional Composite Materials Research Center Korea Institute of Science and TechnologyJeonbuk 55324Republic of Korea SKKU Advanced Institute of Nanotechnology Sungkyunkwan UniversitySuwon 16419Republic of Korea Division of Nano&Information Technology KIST SchoolUniversity of Science and TechnologySeoul 02792Republic of Korea

We,for the first time,report the nanoscopic imaging study of anomalous infrared(IR)phonon enhancement of bilayer graphene,originated from the charge imbalance between the top and bottom layers,resulting in the enhancement of E1u mode of bilayer graphene near 0.2 *** modified the multifrequency atomic force microscope platform to combine photo-induced force microscope with electrostatic/Kelvin probe force microscope constituting a novel hybrid nanoscale optical-electrical force imaging *** enables to observe a correlation between the IR response,doping level,and topographic information of the graphene *** the nanoscale spectroscopic image measurements,we demonstrate that the charge imbalance at the graphene interface can be controlled by chemical(doping effect via Redox mechanism)and mechanical(triboelectric effect by the doped cantilever)***,we can also diagnosis the subsurface cracks on the stacked few-layer graphene at nanoscale,by monitoring the strain-induced IR phonon *** approach provides new insights into the development of graphene-based electronic and photonic devices and their potential applications.

关键词： electrical force optical

Analysis of Reaction force and Locomotor Behavior on Geckos in Time-and Frequency-domain during Climbing on Vertical Substrates

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Journal of Bionic Engineering 2019年第1期16卷 115-129页

作者： Qijun Jiang Zhouyi Wang Jun Zhou Weidong Chen Zhendong Dai Institute of Bio-inspired Structure and Surface Engineering Nanjing University of Aeronauties and AstronauticsNanjing 210016China State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China College of Astronautics Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Since the commencement of climbing robots,the moving ability of climbing robots has continuously lagged far behind that of climbing animal.A primary cause is the insufficient understanding of how animals govern their climbing *** reveal the mechanism of vertical locomotion and enhance the performance of climbing robots,we have measured the reaction forces acting on climbing geckos and recorded the locomotor behaviors *** coordinates of reference points were regressed to analyze kinematic feature ***,the data of reaction forces were further processed by fast Fourier transform and wavelet transform to acquire time-frequency domain *** results show a good agreement between the reaction forces and the locomotor behaviors in time-frequency domain;the main locomotor frequency of trunk in fore-aft direction is twice that in lateral direction;the excellent adhesion system of geckos enables them to climbing up vertical substrate with not onIy a very tiny impact in time scale but also not easily identifiable characteristics in *** research will help deepen our understanding of the climbing locomotion,and provide a more precise prototype for the design of gecko-like robot.

关键词： reaction force time-frequency domain analysis biomechanics gecko power spectral density

Direct numerical simulation on relevance of fluctuating velocities and drag reduction in turbulent channel flow with spanwise space-dependent electromagnetic force

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Chinese Physics B 2019年第5期28卷 166-174页

作者： Dai-Wen Jiang Hui Zhang Bao-Chun Fan An-Hua Wang Science and Technology on Transient Physics Laboratory Nanjing University of Science and Technology

Based on the Fourier–Chebyshev spectral method, the control of turbulent channel flow by space-dependent electromagnetic force and the mechanism of drag reduction are investigated with direct numerical simulation(DNS) methods for different Reynolds numbers. A formula is derived to express the relation between fluctuating velocities and the friction drag coefficient. With the application of electromagnetic force, the in-depth relations among the fluctuating velocities near the wall, Reynolds stress, and the effect of drag reduction for different Reynolds numbers are discussed. The results indicate that the maximum drag reductions can be obtained with an optimal combination of parameters for each case of different Reynolds numbers. The fluctuating velocities along the streamwise and normal directions are suppressed significantly,while the fluctuating velocity along the spanwise direction is enhanced dramatically due to the spanwise electromagnetic force. However, the values of Reynolds stress depend on the fluctuating velocities along the streamwise and normal directions rather than that along the spanwise direction. Therefore, the significant effect of drag reduction is obtained. Moreover,the maximum drag reduction is weakened due to the decay of control effect for fluctuating velocities as the Reynolds number increases.

关键词： flow control turbulent channel flow electromagnetic force direct numerical simulation

Low temperature annealing of metals with electrical wind force effects

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Journal of Materials Science & Technology 2019年第4期35卷 465-472页

作者： Daudi Waryoba Zahabul Islam Baoming Wang Aman Haque Engineering Applied MaterialsPenn State UniversityCollege Place Mechanical & Nuclear Engineering Penn State UniversityUniversity Park

Conventional annealing is a slow, high temperature process that involves heating atoms uniformly, i.e., in both defective and crystalline regions. This study explores an electrical alternative for energy efficiency,where moderate current density is used to generate electron wind force that produces the same outcome as the thermal annealing process. We demonstrate this on a zirconium alloy using in-situ electron back scattered diffraction(EBSD) inside a scanning electron microscope(SEM) and juxtaposing the results with that from thermal annealing. Contrary to common belief that resistive heating is the dominant factor, we show that 5 × 10~4 A/cm^2 current density can anneal the material in less than 15 min at only135?C. The resulting microstructure is essentially the same as that obtained with 600?C processing for360 min. We propose that unlike temperature, the electron wind force specifically targets the defective regions, which leads to unprecedented time and energy efficiency. This hypothesis was investigated with molecular dynamics simulation that implements mechanical equivalent of electron wind force to provide the atomistic insights on defect annihilation and grain growth.

关键词： Annealing Grain-growt Electron backscattered diffraction(EBSD) Molecular dynamics simulations Electron wind force

Cyclic testing of moment-shear force interaction in reinforced concrete shear wall substructures

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Earthquake Engineering and Engineering Vibration 2020年第2期19卷 465-481页

作者： Ke Du Huan Luo Jingjiang Sun Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering MechanicsChina Earthquake AdministrationHarbin 150080China

Previous quasi-static cyclic tests of shear walls,which routinely used an incremental lateral displacement test protocol with a constant axial load,failed to reflect the character of moment-shear force interaction of prototype *** study the effect of the moment-shear force interaction on the seismic performance of shear walls,three identical 2-story shear wall specimens with different loading patterns were constructed at 1/2 scale,to represent the lower portion of an 11-story high-rise building,and were tested under reversed cyclic *** axial force,shear force and bending moment were simultaneously applied to simulate the effects of gravity loads and earthquake excitations on the *** axial force and bending moment delivered from the upper structure were applied to the top of the specimens by two vertical actuators,and the shear force was applied to the specimens by two horizontal actuators.A mixed force-displacement control test program was adopted to ensure that the bending moment and the lateral shear were increased *** experimental results show that the moment-shear force interaction had a significant effect on the failure pattern,hysteretic characteristics,ductility and energy dissipation of the *** is recommended that moment-shear force interaction should be considered in the loading condition of RC shear wall substructures cyclic tests.

关键词： shear walls quasi-static cyclic test moment-shear force interaction collapse test hysteretic curves forcedisplacement mixed control test

Maximum force of Inclined Pullout of A Torpedo Anchor in Cohesive Beds

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China Ocean Engineering 2019年第3期33卷 333-343页

作者： WANG Cheng CHEN Xiao-hui YU Guo-liang SKLOE CISSE School of Naval Architecture Ocean 7338 Civil Engineering Shanghai Jiao Tong University Shanghai 200240 China

Torpedo anchors have been used in mooring systems for deep-water oil and gas projects owing to their prominent advantages, such as low cost and easy installation. The maximum force of torpedo anchors is crucial not only to the safety and stability of vessels and other marine facilities, but also for an economical design. It is necessary to develop reliable formula for fast predicting their maximum inclined force of a torpedo anchor in cohesive beds. In this study, the maximum inclined force of a torpedo anchor vertically embedded in cohesive beds was extensively investigated. 316 sets of inclined pullout laboratory tests were carried out for 9 differently shaped torpedo anchors which were vertically embedded in different cohesive beds. The loading curves were automatically acquisitioned and their characteristics were analyzed. The load angle relative to the horizontal varied from 20° to 90°. A new formula for fast calculating the maximum inclined force of the torpedo anchor vertically embedded in cohesive beds was obtained based on force analysis and a nonlinear regression on the data from the present and other studies. Effect aspects on the tests are discussed and further studies are highlighted.

关键词： torpedo anchor maximum inclined force cohesive bed load angle embedment depth