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Chinese Journal of Mechanical Engineering 2024年第3期37卷 151-169页

作者： Jianwei Wang Haoxi Zhang Shaocun Han Hang Li Peng Wang Kai Feng State key laboratory of advanced design and Manufacturing for vehicle body Hunan UniversityChangsha 410082China

Low damping characteristics have always been a key sticking points in the development of gas *** application of squeeze film dampers can significantly improve the damping performance of gas lubricated *** paper proposed a novel hermetic diaphragm squeeze film damper(HDSFD)for oil-free turbomachinery supported by gas lubricated *** types of HDSFDs with symmetrical structure were proposed for good damping *** considering the compressibility of the damper fluid,based on hydraulic fluid mechanics theory,a dynamic model of HDSFDs under medium is proposed,which successfully reflects the frequency dependence of force *** on the dynamic model,the effects of damper fluid viscosity,bulk modulus of damper fluid,thickness of damper fluid film and plunger thickness on the dynamic stiffness and damping of HDSFDs were *** experimental test rig was assembled and series of experimental studies on HDSFDs were *** damper fluid transverse flow is added to the existing HDSFD concept,which aims to make the dynamic force coefficients independent of *** the force coefficient is still frequency dependent,the damping coefficient at high frequency excitation with damper fluid supply twice as that without damper fluid *** results serve as a benchmark for the calibration of analytical tools under development.

关键词： Hermetic diaphragm squeeze film damper Compressibility Dynamic model Experimental studies

Greatly enhanced corrosion/wear resistances of epoxy coating for Mg alloy through a synergistic effect between functionalized graphene and insulated blocking layer

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Journal of Magnesium and Alloys 2024年第1期12卷 332-344页

作者： Z.Y.Xue X.J.Li J.H.Chu M.M.Li D.N.Zou L.B.Tong School of Metallurgical Engineering Xi’an University of Architecture and TechnologyXi’an 710055China State key laboratory of advanced design and Manufacturing for vehicle body Hunan UniversityChangsha 410082China

The poor corrosion and wear resistances of Mg alloys seriously limit their potential applications in various *** conventional epoxy coating easily forms many intrinsic defects during the solidification process,which cannot provide sufficient *** the current study,we design a double-layer epoxy composite coating on Mg alloy with enhanced anti-corrosion/wear properties,via the spin-assisted assembly *** outer layer is functionalized graphene(FG)in waterborne epoxy resin(WEP)and the inner layer is Ce-based conversion(Ce)*** FG sheets can be homogeneously dispersed within the epoxy matrix to fill the intrinsic defects and improve the barrier *** Ce film connects the outer layer with the substrate,showing the transition *** corrosion rate of Ce/WEP/FG composite coating is 2131 times lower than that of bare Mg alloy,and the wear rate is decreased by~90%.The improved corrosion resistance is attributed to the labyrinth effect(hindering the penetration of corrosive medium)and the obstruction of galvanic coupling *** synergistic effect derived from the FG sheet and blocking layer exhibits great potential in realizing the improvement of multi-functional integration,which will open up a new avenue for the development of novel composite protection coatings of Mg alloys.

关键词： Mg alloy Functionalized graphene Epoxy coating Corrosion/wear resistance Blocking layer

Safe Efficient Policy Optimization Algorithm for Unsignalized Intersection Navigation

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IEEE/CAA Journal of Automatica Sinica 2024年第9期11卷 2011-2026页

作者： Xiaolong Chen Biao Xu Manjiang Hu Yougang Bian Yang Li Xin Xu State key laboratory of advanced design and Manufacturing for vehicle body the College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082China State key laboratory of advanced design and Manufacturing for vehicle body the College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082 Wuxi Intelligent Control Research Institute(WICRI)of Hunan University Wuxi 214115China College of Intelligence Science and technology Institute of Unmanned SystemsNational University of Defense TechnologyChangsha 410073China

Unsignalized intersections pose a challenge for autonomous vehicles that must decide how to navigate them safely and *** paper proposes a reinforcement learning(RL)method for autonomous vehicles to navigate unsignalized intersections safely and *** method uses a semantic scene representation to handle variable numbers of vehicles and a universal reward function to facilitate stable learning.A collision risk function is designed to penalize unsafe actions and guide the agent to avoid them.A scalable policy optimization algorithm is introduced to improve data efficiency and safety for vehicle learning at *** algorithm employs experience replay to overcome the on-policy limitation of proximal policy optimization and incorporates the collision risk constraint into the policy optimization *** proposed safe RL algorithm can balance the trade-off between vehicle traffic safety and policy learning *** intersection scenarios with different traffic situations are used to test the algorithm and demonstrate its high success rates and low collision rates under different traffic *** algorithm shows the potential of RL for enhancing the safety and reliability of autonomous driving systems at unsignalized intersections.

关键词： Autonomous driving decision-making reinforcement learning(RL) unsignalized intersection

Multi-layer quasi-zero-stiffness meta-structure for high-efficiency vibration isolation at low frequency

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Applied Mathematics and Mechanics(English Edition) 2024年第7期45卷 1189-1208页

作者： Jiahao ZHOU Jiaxi ZHOU Hongbin PAN Kai WANG Changqi CAI Guilin WEN College of Mechanical and vehicle Engineering Hunan UniversityChangsha410082China State key laboratory of advanced design and Manufacturing for vehicle body The Ministry of Science and TechnologyChangsha410082China School of Mechanical Engineering Zhejiang Sci-Tech UniversityHangzhou310018China School of Mechanical Engineering Yanshan UniversityQinhuangdao066004Hebei ProvinceChina

An easily stackable multi-layer quasi-zero-stiffness(ML-QZS)meta-structure is proposed to achieve highly efficient vibration isolation performance at low ***,the distributed shape optimization method is used to design the unit cel,i.e.,the single-layer QZS(SL-QZS)***,the stiffness feature of the unit cell is investigated and verified through static ***,the unit cells are stacked one by one along the direction of vibration isolation,and thus the ML-QZS meta-structure is ***,the dynamic modeling of the ML-QZS vibration isolation metastructure is conducted,and the dynamic responses are obtained from the equations of motion,and verified by finite element(FE)***,a prototype of the ML-QZS vibration isolation meta-structure is fabricated by additive manufacturing,and the vibration isolation performance is evaluated *** results show that the vibration isolation performance substantially enhances when the number of unit cells *** importantly,the ML-QZS meta-structure can be easily extended in the direction of vibration isolation when the unit cells are properly ***,the ML-FQZS vibration isolation meta-structure should be a fascinating solution for highly efficient vibration isolation performance at low frequency.

关键词： quasi-zero stiffness(QZS) meta-structure high efficiency low frequency vibration isolation

In-vehicle Network Injection Attacks Detection Based on Feature Selection and Classification

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Automotive Innovation 2024年第1期7卷 138-149页

作者： Haojie Ji Liyong Wang Hongmao Qin Yinghui Wang Junjie Zhang Biao Chen key laboratory of Modern Measurement and Control technology Ministry of EducationBeijing Information Science and Technology UniversityBeijing 100192China State key laboratory of advanced design and Manufacturing for vehicle body College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082China School of Transportation Science and Engineering Beihang UniversityBeijing 100191China Hefei Innovation Research Institute Beihang UniversityHefei 230012China

Detecting abnormal data generated from cyberattacks has emerged as a crucial approach for identifying security threats within in-vehicle *** transmission of information through in-vehicle networks needs to follow specific data for-mats and communication protocols ***,statistical algorithms are employed to learn these variation rules and facilitate the identification of abnormal ***,the effectiveness of anomaly detection outcomes often falls short when confronted with highly deceptive in-vehicle network *** this study,seven representative classification algorithms are selected to detect common in-vehicle network attacks,and a comparative analysis is employed to identify the most suitable and favorable detection *** consideration of the communication protocol characteristics of in-vehicle networks,an optimal convolutional neural network(CNN)detection algorithm is proposed that uses data field characteristics and classifier selection,and its comprehensive performance is *** addition,the concept of Hamming distance between two adjacent packets within the in-vehicle network is introduced,enabling the proposal of an enhanced CNN algorithm that achieves robust detection of challenging-to-identify abnormal *** paper also presents the proposed CNN classifica-tion algorithm that effectively addresses the issue of high false negative rate(FNR)in abnormal data detection based on the timestamp feature of data *** experimental results validate the efficacy of the proposed abnormal data detection algorithm,highlighting its strong detection performance and its potential to provide an effective solution for safeguarding the security of in-vehicle network information.

关键词： Classification algorithm Anomaly detection In-vehicle network Feature extraction Injecting attack

Electro-spraying/spinning: A novel battery manufacturing technology

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Green Energy & Environment 2024年第1期9卷 81-88页

作者： Zhuan Hu Jiaxin Hao Dongyang Shen Caitian Gao Zhaomeng Liu Jianguo Zhao Bingan Lu School of Physics and Electronics Hunan UniversityChangsha410082China State key laboratory of advanced design and Manufacturing for vehicle body Hunan Provincial Key Laboratory of Multi-electron Based Energy Storage DevicesHunan UniversityChangsha410082China School of Physics and Electronic Information Luoyang Normal UniversityLuoyang471934China Section of Environmental Protection key laboratory of Eco-Industry School of MetallurgyNortheastern UniversityShenyangLiaoning110819China

Lithium-ion battery(LIB) industry seems to have met its bottle neck in cutting down producing costs even though much efforts have been put into building a complete industrial chain. Actually, manufacturing methods can greatly affect the cost of battery production. Up to now, lithium ion battery producers still adopt manufacturing methods with cumbersome sub-components preparing processes and costly assembling procedures, which will undoubtedly elevate the producing cost. Herein, we propose a novel approach to directly assemble battery components(cathode, anode and separator) in an integrated way using electro-spraying and electro-spinning technologies. More importantly, this novel battery manufacturing method can produce LIBs in large scale, and the products show excellent mechanical strength, flexibility, thermal stability and electrolyte wettability. Additionally, the performance of the as-prepaed Li Fe PO_(4)||graphite full cell produced by this new method is comparable or even better than that produced by conventional manufacturing approach. In brief, this work provides a new promising technology to prepare LIBs with low cost and better performance.

关键词： Electro-spraying Electro-spinning Integrated electrode Lithium-ion battery

Advances in multi-scale design and fabrication processes for thick electrodes in lithium-ion batteries

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Energy Reviews 2024年第2期3卷 14-30页

作者： Xiuxue Liu Yubin Zeng Wei Yuan Guanhua Zhang Huai Zheng Zhongxue Chen key laboratory of Hydraulic Machinery Transients Ministry of EducationSchool of Power and Mechanical EngineeringWuhan UniversityWuhan430072China School of Mechanical and Automotive Engineering South China University of TechnologyGuangzhou510640GuangdongChina State key laboratory of advanced design and Manufacturing for vehicle body College of Mechanical and Vehicle EngineeringHunan UniversityChangsha410082China Greater Bay Area Institute for Innovation Hunan UniversityGuangzhou511300China

In the contemporary era,lithium-ion batteries have gained considerable attention in various industries such as 3C products,electric vehicles and energy storage systems due to their exceptional *** the rapid progress in the energy storage sector,there is a growing demand for greater energy density in lithium-ion *** the use of thick electrodes is a straightforward and effective approach to enhance the energy density of battery,it is hindered by the sluggish reaction dynamics and insufficient mechanical ***,we comprehensively review recent advances in the field of thick electrodes for lithium-ion batteries to overcome the bottlenecks in the development of thick electrodes and achieve efficient fabrication for high-performance lithium-ion ***,a systematic analysis is performed to identify the factors affecting the performance of the thick *** correlation between electrode materials,structural parameters,and performance is also ***,the viable strategies for constructing thick electrodes with improved properties are summarize,including high throughput,high conductivity and low tortuosity,in both material development and structural *** addition,recent advances in efficient fabrication methods for thick electrode fabrication are reviewed,with a comprehensive assessment of their merits,limitations,and applicable ***,a comprehensive overview of the multiscale design and manufacturing process for thick electrodes in lithium-ion batteries is provided,accompanied by valuable insights into design considerations that are crucial for future advances in this area.

关键词： Lithium-ion battery Thick electrode High energy density Electrode structure Multi-scale design Material development

design and Performance Analysis of HMDV Dynamic Inertial Suspension Based on Active Disturbance Rejection Control

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Computer Modeling in Engineering & Sciences 2024年第8期140卷 1485-1506页

作者： Xiaofeng Yang Wei Wang Yujie Shen Changning Liu Tianyi Zhang School of Automotive and Traffic Engineering Jiangsu UniversityZhenjiang212013China Automotive Engineering Research Institute Jiangsu UniversityZhenjiang212013China Chongqing key laboratory of Urban Rail Transit System Integration and Control Chongqing400074China State key laboratory of advanced design and Manufacturing technology for vehicle Hunan universityChangsha410082China

This paper addresses the impact of vertical vibration negative effects,unbalanced radial forces generated by the static eccentricity of the hub motor,and road excitation on the suspension performance of Hub Motor Driven vehicle(HMDV).A dynamic inertial suspension based on Active Disturbance Rejection Control(ADRC)is proposed,combining the vertical dynamic characteristics of dynamic inertial suspension with the features of ADRC,which distinguishes between internal and external disturbances and arranges the transition ***,a simulation model of the static eccentricity of the hub motor is established to simulate the unbalanced radial electromagnetic force generated under static eccentricity.A quarter-vehicle model of an HMDV with a controllable dynamic inertial suspension is then ***,the passive suspension model is studied under different grades of road excitation,and the impact mechanism of suspension performance at speeds of 0–20 m/s is ***,the three main components within the ADRC controller are designed for the second-order controlled system,and optimization algorithms are used to optimize its internal ***,the performance of the traditional passive suspension,the PID-based controllable dynamic inertial suspension,and the ADRC-based controllable dynamic inertial suspension are analyzed under different road *** results show that,under sinusoidal road input,the ADRC-based controllable dynamic inertial suspension exhibits a 52.3%reduction in the low-frequency resonance peak in the vehicle body acceleration gain diagram compared to the traditional passive suspension,with significant performance optimization in the high-frequency *** random road input,the ADRC-based controllable dynamic inertial suspension achieves a 29.53%reduction in the root mean square value of vehicle body acceleration and a 14.87%reduction in dynamic tire *** indicates that the designed controllable dynamic inertia

关键词： HMDV static eccentricity ADRC dynamic inertial suspension road excitation

基于模拟-建模研究化学与温度对难熔高熵合金力学行为和变形机制的影响

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Acta Mechanica Sinica 2024年第2期40卷 103-115页

作者：李甲任思危刘彬 Peter K.Liaw 方棋洪 State key laboratory of advanced design and Manufacturing for vehicle body College of Mechanical and Vehicle EngineeringHunan UniversityChangsha410082China State key laboratory of Powder Metallurgy Central South UniversityChangsha410083China Department of Materials Science and Engineering The University of TennesseeKnoxville37996USA

难熔高熵合金在高温下表现出优异的性能,突破了传统高温合金的工作温度上限.我们采用原子模拟研究了化学元素分布和温度对等原子比MoNbTaW难熔高熵合金变形机制的影响.根据微观结构演化,建立了基于微观结构的本构模型,定量评估多种强化... 详细信息

难熔高熵合金在高温下表现出优异的性能,突破了传统高温合金的工作温度上限.我们采用原子模拟研究了化学元素分布和温度对等原子比MoNbTaW难熔高熵合金变形机制的影响.根据微观结构演化,建立了基于微观结构的本构模型,定量评估多种强化机制的贡献.结果表明,应变硬化后,流动应力随应变呈锯齿状剧烈波动.由于退火结构的溶质浓度降低,温度升高降低了应变硬化率和流动应力波动幅度.变形孪晶在变形机制中起着关键作用,能够通过位错基塑性和晶粒中的非晶形核进一步调节局部变形.有序结构的存在强烈影响了应力和应变分配.固溶强化和晶界强化对流动应力的贡献很大,孪晶强化对流动压力的贡献很小.原子模拟和力学模型为深入理解难熔高熵合金变形行为及性能的精确预测提供依据.

关键词：流动应力固溶强化强化机制高温合金高熵合金变形机制晶界强化溶质浓度

A human-sensitive frequency band vibration isolator for heavy-duty truck seats

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Applied Mathematics and Mechanics(English Edition) 2024年第10期45卷 1733-1748页

作者： Qingqing LIU Shenlong WANG Ge YAN Hu DING Haihua WANG Qiang SHI Xiaohong DING Huijie YU School of Mechanical Engineering University of Shanghai for Science and TechnologyShanghai 200093China State key laboratory of Mechanical System and Vibration School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China Shanghai key laboratory of Mechanics in Energy Engineering Shanghai Frontier Science Center of MechnoinformaticsShanghai Institute of Applied Mathematics and MechanicsSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai 200072China State key laboratory of advanced design and Manufacturing for vehicle body College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082China Yanfeng Adient Seating Co. Ltd.Shanghai 201315China College of Mechanical and Electrical Engineering Jiaxing Nanhu UniversityJiaxing 314001Zhejiang ProvinceChina

In this study,a human-sensitive frequency band vibration isolator(HFBVI)with quasi-zero stiffness(QZS)characteristics for heavy-duty truck seats is designed to improve the comfort of heavy-duty truck drivers on uneven ***,the analytical expressions for the force and displacement of the HFBVI are derived with the Lagrange equation and d'Alembert's principle,and are validated through the prototype restoring force ***,the harmonic balance method(HBM)is used to obtain the dynamic responses under harmonic excitation,and further the influence of pre-stretching on the dynamic characteristics and transmissibility is ***,the experimental prototype of the HFBVI is fabricated,and vibration experiments are conducted under harmonic excitation to verify the vibration isolation performance(VIP)of the proposed vibration *** experimental results indicate that the HFBVI can effectively suppress the frequency band(4-8 Hz)to which the human body is sensitive to vertical *** addition,under real random road spectrum excitation,the HFBVI can achieve low-frequency vibration isolation close to 2 Hz,providing new prospects for ensuring the health of heavy-duty truck drivers.

关键词： human-sensitive frequency band quasi-zero stiffness(QZS) heavy-duty truck seat real random road spectrum low-frequency vibration isolation