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Preload control Method of Threaded Fasteners:A Review

Chinese Journal of Mechanical Engineering 2024年第5期37卷 40-59页

作者： Xing Yan Zhifeng Liu Mingpo Zheng Ying Li Yuezhen Wang Wentao Chen College of Mechanical&Energy Engineering Beijing University of TechnologyBeijing 100124China Beijing Key Laboratory of Advanced Manufacturing Technology Beijing University of TechnologyBeijing 100124China Key Laboratory of CNC Equipment Reliability Ministry of EducationSchool of Mechanical and Aerospace EngineeringJilin UniversityChangchun 130012China

Threaded fasteners are one of the most commonly used connection methods for mechanical *** primary function is to generate appropriate clamping forces and fasten the connected *** inappropriate preload can cause loosening,fatigue fracture,and other *** will affect the safety and reliability of mechanical *** precise control of the preload has become a critical issue in mechanical assembly *** the past few decades,various tightening measures and methods have been proposed to address this ***,many problems continue to exist with practical applications that have not been reviewed comprehensively and ***,various control methods were summarized systematically,and their advantages and disadvantages in engineering applications were *** control is the most widely used tightening method owing to its simple operation and low ***,the research on the torque control method was summarized systematically from three aspects:the torque-preload correlation formula,effective friction radius,and friction characteristics during *** addition,the special circumstances that may increase preload uncertainty were ***,based on a summary of the current research status,the prospects for future research were *** study would aid researchers in extensively understanding the problems in preload control.

关键词： Threaded fasteners Preload Tightening method Torque control method Friction characteristics

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Accuracy analysis for distributed dynamic state estimation in large-scale systems with a cyclic network graph

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Science China(Information Sciences) 2023年第9期66卷 78-93页

作者： Mingyan ZHU Rui WANG Xiaodong MIAO Tianju SUI School of Control Science and Engineering Dalian University of Technology Key Laboratory of Intelligent Control and Optimization for Industrial Equipment of Ministry of Education School of Aeronautics and Astronautics Dalian University of Technology Key Laboratory of Advanced Technology for Aerospace Vehicles School of Mechanical and Power Engineering Nanjing Tech University

This paper addresses a distributed dynamic state estimation problem in large-scale systems characterized by a cyclic network graph. The objective is to develop a distributed estimation algorithm for each node to generate local state estimations, based on the coupled measurements and boundary information exchanged with neighboring nodes. Our proposed approach is grounded in the maximum a posteriori(MAP)estimation method, which yields suboptimal results in acyclic network graphs compared with the centralized MAP approach. We extend this approach to systems with a cyclic network graph. Furthermore, we provide an accuracy analysis by deriving bounds for the differences in estimation error covariance and state estimation between the proposed distributed algorithm and the suboptimal centralized MAP method. These bounds apply to a specific category of systems that satisfy certain conditions, including cyclic topology and sparse connections. We demonstrate that these bounds converge asymptotically, with the rate of convergence determined by the loop-free depth of the graph. The loop-free depth of the graph refers to the maximum number of nodes that can be traversed in a cycle without revisiting any node. Finally, we demonstrate the validity of the algorithm through numerical examples.

关键词： distributed state estimation maximum a posteriori estimation cyclic network graph

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Constructing high-capacity and flexible aqueous zinc-ion batteries with air-recharging capability using organic cathodes

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Chinese Chemical Letters 2024年第3期35卷 468-472页

作者： Xiaojuan Chen Haoqi Su Baozhu Yang Xiaocen Liu Xiuting Song Lixin Su Gui Yin Qi Liu Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology Advanced Catalysis Green Manufacturing Collaborative Innovation Center and School of Petrochemical EngineeringChangzhou UniversityChangzhou 213164China State Key Laboratory of Coordination Chemistry Nanjing UniversityNanjing 210093China

Flexible aqueous zinc-ion batteries(AZIBs)with air-recharging capability are a promising self-powered system applied in future wearable *** is desired to develop high-capacity air-rechargeable ***,we developed a flexible AZIB with air-recharging capability based on trinitrohexaazatrinaphthylene(TNHATN)cathode and a ZnSO_(4)*** flexible Zn//TNHATN battery exhibits high volumetric energy density(21.36 mWh/cm^3)and excellent mechanical ***,the discharged flexible Zn//TNHATN battery can be chemical self-charged via the redox reaction between TNHATN cathode and O_(2)from the *** oxidation in air for 15 h,such flexible Zn//TNHATN battery can deliver a high specific capacity of 320 mAh/g at 0.5 A/g,displaying excellent air-recharging ***,this flexible Zn//TNHATN battery also works well in chemical or/and galvanostatic charging mixed modes,showing *** work provides a new insight for designing flexible aqueous self-powered systems.

关键词： Aqueous zinc-ion battery Trinitrohexaazatrinaphthylene Organic cathode materials Flexible air-rechargeable battery Self-powered system

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Strain sensor on a chip for quantifying the magnitudes of tensile stress on cells

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Microsystems & Nanoengineering 2024年第3期10卷 305-315页

作者： Yuyin Zhang Yue Wang Hongze Yin Jiahao Wang Na Liu Songyi Zhong Long Li Quan Zhang Tao Yue School of Mechatronics Engineering and Automation Shanghai UniversityShanghaiChina School of Future Technology Shanghai UniversityShanghaiChina Key Laboratory of Advanced Manufacturing Technology of Zhejiang Province School of Mechanical EngineeringZhejiang UniversityHangzhouChina Shanghai Key Laboratory of Intelligent Manufacturing and Robotics Shanghai UniversityShanghaiChina Shanghai Institute of Intelligent Science and Technology Tongji UniversityShanghaiChina

During cardiac development,mechanotransduction from the in vivo microenvironment modulates cardiomyocyte growth in terms of the number,area,and arrangement ***,the response of cells to different degrees of mechanical stimuli is ***-on-a-chip,as a platform for investigating mechanical stress stimuli in cellular mimicry of the in vivo microenvironment,is limited by the lack of ability to accurately quantify externally induced ***,previous technology lacks the integration of external stimuli and feedback sensors in microfluidic platforms to obtain and apply precise amounts of external ***,we designed a cell stretching platform with an in-situ *** in-situ liquid metal sensors can accurately measure the mechanical stimulation caused by the deformation of the vacuum cavity exerted on *** platform was applied to human cardiomyocytes(AC16)under cyclic strain(5%,10%,15%,20 and 25%),and we found that cyclic strain promoted cell growth induced the arrangement of cells on the membrane to gradually unify,and stabilized the cells at 15%amplitude,which was even more effective after 3 days of *** platform’s precise control and measurement of mechanical forces can be used to establish more accurate in vitro microenvironmental models for disease modeling and therapeutic research.

关键词： stress deformation arrangement

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Symmetry-breaking of LiMn_(6) hexatomic-ring in grain surface of Li_(2)MnO_(3)

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Journal of Energy Chemistry 2023年第6期81卷 110-117,I0004页

作者： Lihang Wang Shu Zhao Boya Wang Haijun Yu Institute of Advanced Battery Materials and Devices Faculty of Materials and ManufacturingBeijing University of TechnologyBeijing 100124China Key Laboratory of Advanced Functional Materials Ministry of EducationBeijing University of TechnologyBeijing 100124China

LiMn_(6) hexatomic-rings act as functional units in Li-rich layered oxides(LLOs),which determine the capacity,voltage,and structural stability of ***,the symmetry of the LiMn_(6) hexatomic-ring is always broken,especially in the grain surface of LLOs,which will greatly affect its electrochemical ***,the symmetry-breaking of LiMn_(6) hexatomic-ring in the grain surface of Li_(2)MnO_(3) was studied,and their effect on charge compensation mechanism and structure evolution behavior was thoroughly *** results show that the electrochemical activity of the symmetry-broken LiMn_(6) hexatomic-ring is higher than that of the unbroken LiMn_(6),and the former is more favorable for spinelization on the grain ***,the exposure proportion of crystallographic planes with different symmetry-broken LiMn_(6) hexatomic-ring has also been discussed,which can be adjusted by changing the partial pressure of *** in-depth understanding of the symmetry-breaking of LiMn_(6) hexatomic-ring will provide more targeted strategies for designing high-performance LLOs cathodes for lithium-ion batteries.

关键词： Li-rich layered oxides LiMn_(6)functional unit Symmetry-breaking Surface structure Density functional theory

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Regulation mechanism of biomolecule interaction behaviors on the superlubricity of hydrophilic polymer coatings

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Friction 2022年第1期10卷 94-109页

作者： Caixia ZHANG Junmin CHEN Mengmeng LIU Yuhong LIU Zhifeng LIU Hongyan CHU Qiang CHENG Jianhua WANG Institute of Advanced Manufacturing and Intelligent Technology.Beijing University of Technology Beijing 100124China Beijing Key Laboratory of Advanced Manufacturing Technology Beijing University of TechnologyBeijing 100124China State Key Laboratory of Tribology.Tsinghua University Beijing 100084China

Hydrophilic polymer coatings can improve the surface characteristics of artificial ***,because they are used in vivo,they inevitably come into contact with biomolecules that affect their interfacial tribological *** this paper,the friction behaviors of poly(vinylphosphonic acid)(PVPA)-modified Ti6Al4V and polytetrafluorethylene balls were analyzed using albumin,globulin,aggrecan,and hyaluronic acid as *** interaction properties and dynamic adsorption characteristics of the biomolecules and PVPA molecules were explored by a quartz crystal microbalance to identify the cause of the friction *** was found that protein molecules disturbed the superlubricity of the PVPA-phosphate-buffered saline system because of the formation of a stable adsorption film,which replaced the interfacial characteristics of the PVPA ***,with their excellent hydration properties and polymer structure,had an unstable dynamic interaction or zero adsorption with PVPA molecules,and hardly changed the superlubricity of the PVPA and phosphate-buffered-saline *** influence mechanism of the specific friction of proteins and polysaccharides was *** were observed among different *** can potentially reduce protein *** result of the synergistic regulation of the friction coefficient for PVPA-modified Ti6Al4V is approximately *** results of this study will provide a theoretical basis for the use of polymer coatings in vivo.

关键词： friction interaction adsorption

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Analysis of mesoscopic mechanical dynamic characteristics of ballast bed with under sleeper pads

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Railway Engineering Science 2024年第1期32卷 107-123页

作者： Xiong Yang Liuyang Yu Xuejun Wang Zhigang Xu Yu Deng Houxu Li Faculty of Mechanical and Electrical Engineering Kunming University of Science and TechnologyKunmingChina Yunnan Provincial Key Laboratory of Advanced Equipment Intelligent Manufacturing Technology KunmingChina

The meso-dynamical behaviour of a high-speed rail ballast bed with under sleeper pads(USPs)was *** geometrically irregular refined discrete element model of the ballast particles was constructed using 3D scanning techniques,and the 3D dynamic model of the rail-sleeper-ballast bed was constructed using the coupled discrete element method-multiflexible-body dynamics(DEM-MFBD)*** analyse the meso-mechanical dynamics of the ballast bed with USPs under dynamic load on a train and verify the correctness of the model in laboratory *** is shown that the deformation of the USPs increases the contact area between the sleeper and the ballast particles,and subsequently the number of contacts between *** the depth of the granular ballast bed increases,the contact area becomes larger,and the contact force between the ballast particles gradually *** the action of the elastic USPs,the contact forces between ballast particles are reduced and the overall vibration level of the ballast bed can be *** settlement of the granular ballast bed occurs mainly at the shallow position of the sleeper bottom,and the installation of the elastic USPs can be effective in reducing the stress on the ballast particles and the settlement of the ballast bed.

关键词： Under sleeper pads Ballast bed Discrete element method Mesoscopic mechanical dynamic characteristics

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Design and characteristic research of a novel electromechanical-hydraulic hybrid actuator with two transmission mechanisms

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Frontiers of Mechanical Engineering 2023年第2期18卷 189-204页

作者： Shufei QIAO Long QUAN Yunxiao HAO Lei GE Lianpeng XIA Key Laboratory of Advanced Transducers and Intelligent Control System of Ministry of Education Taiyuan University of TechnologyTaiyuan 030024China

Servo-hydraulic actuators(SHAs)are widely used in mechanical equipment to drive heavy-duty ***,their energy efficiency is low,and their motion characteristics are inevitably affected by uncertain *** actuators(EMAs)possess superior energy efficiency and motion ***,they cannot easily drive heavy-duty mechanisms because of weak bearing *** study proposes and designs a novel electromechanical-hydraulic hybrid actuator(EMHA)that integrates the advantages of EMA and *** mainly features two transmission *** piston of the hydraulic transmission mechanism and the ball screw pair of the electromechanical transmission mechanism are mechanically fixed together through screw bolts,realizing the integration of two types of transmission *** control scheme of the electromechanical transmission mechanism is used for motion control,and the hydraulic transmission mechanism is used for power ***,the mathematical model,structure,and parameter design of the new EMHA are ***,the EMHA prototype and test platform are *** test results prove that the EMHA has good working characteristics and high energy *** with the valve-controlled hydraulic cylinder system,EMHA exhibits a velocity tracking error and energy consumption reduced by 49.7% and 54%,respectively,under the same working conditions.

关键词： electromechanical-hydraulic hybrid actuator(EMHA) integration transmission mechanisms power assistance energy efficiency working characteristics

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Direct-Ink-Writing Printed Strain Rosette Sensor Array with Optimized Circuit Layout

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Chinese Journal of Mechanical Engineering 2023年第4期36卷 205-211页

作者： Peishi Yu Lixin Qi Zhiyang Guo Yu Liu Junhua Zhao Jiangsu Key Laboratory of Advanced Food Manufacturing Equipment and Technology School of Mechanical EngineeringJiangnan UniversityWuxi 214122China Jiangsu Province Engineering Research Center of Micro-Nano Additive and Subtractive Manufacturing Institute of Advanced TechnologyJiangnan UniversityWuxi 214122China

The full-field multiaxial strain measurement is highly desired for application of structural monitoring but still challenging,especially when the manufacturing and assembling for largearea sensing devices is quite *** with the traditional procedure of gluing commercial strain gauges on the structure surfaces for strain monitoring,the recently developed Direct-Ink-Writing(DIW)technology provides a feasible way to directly print sensors on the ***,there are still crucial issues in the design and printing strategies to be probed and ***,in this work,we propose an integrated strategy from layered circuit scheme to rapid manufacturing of strain rosette sensor array based on the DIW *** from the innovative design with simplified circuit layout and the advantages of DIW for printing multilayer structures,here we achieve optimization design principle for strain rosette sensor array with scalable circuit layout,which enable a hierarchical printing strategy for multiaxial strain monitoring in large scale or multiple *** strategy is highly expected to adapt for the emerging requirement in various applications such as integrated soft electronics,nondestructive testing and small-batch medical devices.

关键词： Direct-ink-writing Strain rosette sensor array Layered circuit scheme Printing strategy

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Mechanical reliable,NIR light-induced rapid self-healing hydrogel electrolyte towards flexible zinc-ion hybrid supercapacitors with low-temperature adaptability and long service life

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Journal of Energy Chemistry 2024年第5期92卷 63-73页

作者： Tengjia Gao Na Li Yang Yang Jing Li Peng Ji Yunlong Zhou Jianxiong Xu School of Materials and Advanced Manufacturing Hunan Key Laboratory of Electrochemical Green Metallurgy TechnologyHunan University of TechnologyZhuzhou 412007HunanChina School of Life Sciences and Chemistry Hunan Key Laboratory of Biomedical Nanomaterials and DevicesHunan University of TechnologyZhuzhou 412007HunanChina

Hydrogel electrolytes hold great potential in flexible zinc ion supercapacitors(ZICs)due to their high conductivity,good safety,and ***,freezing of electrolytes at low temperature(subzero)leads to drastic reduction in ionic conductivity and mechanical properties that deteriorates the performance of flexible ***,the mechanical fracture during arbitrary deformations significantly prunes out the lifespan of the flexible ***,a Zn^(2+)and Li^(+)co-doped,polypyrrole-dopamine decorated Sb_(2)S_(3)incorporated,and polyvinyl alcohol/poly(N-(2-hydroxyethyl)acrylamide)double-network hydrogel electrolyte is constructed with favorable mechanical reliability,anti-freezing,and self-healing *** addition,it delivers ultra-high ionic conductivity of 8.6 and 3.7 S m^(-1)at 20 and−30°C,respectively,and displays excellent mechanical properties to withstand tensile stress of 1.85 MPa with tensile elongation of 760%,together with fracture energy of 5.14 MJ m^(-3).Notably,the fractured hydrogel electrolyte can recover itself after only 90 s of infrared illumination,while regaining 83%of its tensile strain and almost 100%of its ionic conductivity during−30–60°***,ZICs coupled with this hydrogel electrolyte not only show a wide voltage window(up to 2 V),but also provide high energy density of 230 Wh kg^(-1)at power density of 500 W kg^(-1)with a capacity retention of 86.7%after 20,000 cycles under 20°***,the ZICs are able to retain excellent capacity even under various mechanical deformation at−30°*** contribution will open up new insights into design of advanced wearable flexible electronics with environmental adaptability and long-life span.

关键词： Flexible zinc ion supercapacitor Hydrogel electrolyte Self-healing Anti-freezing

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