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A decoupled method for time-dependent reliability-based design optimization

Science China(Technological Sciences) 2025年第1期68卷 308-320页

作者： Dequan ZHANG Meide YANG Xu HAN State Key Laboratory of Reliability and Intelligence of Electrical Equipment School of Mechanical EngineeringHebei University of TechnologyTianjin 300401China State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082China

Time-dependent reliability-based design optimization(TRBDO)has received extensive attention because of its ability to achieve optimal solutions that help meet the requirement for whole lifecycle reliability by quantitatively considering dynamic ***,directly solving TRBDO problems is computationally expensive,if not prohibitive,owing to the need to repeatedly evaluate time-dependent probabilistic *** address this challenge,an efficient decoupled method called sequential optimization and time-dependent reliability assessment(SOTRA)is proposed in this *** method transforms the original TRBDO problem,initially formulated probabilistically,into a problem using percentile formulation after discretizing time-dependent performance *** adopting the equivalent minimum performance target point(EMPTP)concept,the TRBDO problem is further converted into an equivalent deterministic optimization problem,which is subsequently solved through a sequential iteration process involving deterministic optimization and time-dependent reliability *** efficiently and robustly search an EMPTP for reliability analysis,a time-dependent self-adaptive finite-step length method is *** verify the proposed SOTRA method against existing TRBDO methods,a numerical example,a benchmark structural design case of a simply supported beam,and an engineering application for flexible wheel design are exemplified in this *** results demonstrate that the proposed SOTRA method exhibits high efficiency and robustness in solving TRBDO problems.

关键词： reliability-based design optimization dynamic uncertainties time-dependent reliability analysis decoupled method sequential optimization and reliability analysis

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Effects of the windshield inclination angle on head/brain injuries in car-to-pedestrian collisions using computational biomechanics models

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Transportation safety and Environment 2024年第2期6卷 1-12页

作者： Fang Wang Mingliang Wang Lin Hu Ke Peng Jiajie Yin Danqi Wang Liangliang Shi Zhou Zhou School of Automotive and Mechanical Engineering Changsha University of Science and TechnologyChangsha 410114HunanChina Hunan Province Key Laboratory of Safety Design and Reliability Technology for Engineering Vehicle Changsha University of Science and TechnologyChangsha 410114HunanChina State Key Laboratory of Vehicle NVH and Safety Technology China Automotive Engineering Research Institute Co.Ltd.Chongqing 401122China Division of Neuronic Engineering KTH Ro y al Institute of TechnologyStockholm 14152Sweden

Car-to-pedestrian collision(CPC)accidents occur frequently,and pedestrians often suffer serious head/brain *** major cause is the primary impact with the ***,we use an umerical sim ulation method to study the influence of the windshield in-clination angle of a passenger car on pedestrian head/brain injury due to CPC *** range of the windshield inclination angle was set at 24°-50°,with an interval of 2°.The results show that the windshield angle significantly affects the pedestrian kine-matics and exerts different effects on the head injury when evaluating with various head injury *** the head peak linear/rotational acceleration and acceleration-based head injury criterion(HIC)/rotational injury criterion(RIC),the predictions at the secondary impact stage have no clear relationship with the windshield angle(R^(2)=0.04,0.07,0.03 and 0.26,respectively)and their distributions are *** the primary impact,the peak linear acceleration and HIC show a weak trend of first decreasing and then increasing with the increasing of the windshield angle,and the rotational acceleration and RIC tend to remain relatively *** the cum ulative strain dama ge measure(CSDM)criterion,the predictions at the primary impact are slightly lower than those at the secondary impact,and the trend of first decreasing and then increasing with the increase in the windshield angle is observed at both impact *** the windshield inclination angle is approximately 32°-40°,the head injury severity in both impact phases is generally lower than that predicted at other windshield angles.

关键词： car-to-pedestrian collision(CPC) head/brain injury head injury criterion(HIC) windshield inclination angle computa-tional biomechanics model(CPCBM)

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Microstructure evolution and precipitation behavior of Al-Mg-Si alloy during initial aging

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China Foundry 2023年第1期20卷 57-62页

作者： Ya-ya Zheng Bing-hui Luo Wei Xie Wang Li Department of Materials Engineering Hunan University of HumanitiesScience and TechnologyLoudi 417000HunanChina College of Materials Science and Engineering Central South UniversityChangsha 410083China Key Laboratory of Safety Design and Reliability Technology for Engineering Vehicle Changsha University of Science&TechnologyChangsha 410114China

The microstructure evolution and precipitation behavior of Al-Mg-Si alloy during initial aging were studied using hardness testing, conductivity testing, differential scanning calorimetry(DSC), and high resolution transmission electron microscopy(HRTEM). The results show that the precipitation sequence of the Al-Mg-Si alloy during initial aging can be represented as: supersaturated solid solution → spherical Mg/Si clusters → needle-like Guinier Preston(GP) zone → β″. Clusters are completely coherent with the Al matrix. The GP zone with relatively complete independent lattice parameters that differ slightly from the Al matrix parameters, is oriented along the direction of <111>Aland lying on {111}Alplane. The strength of the Al-Mg-Si alloy is greatly enhanced by the threedimensional strain field that exists between the β″ phase and the two {200}Alplanes. After aging at 170 ℃ for 6 h, the hardness reaches the peak of 127 HV and remains for a long time. At this stage, the electrical conductivity keeps relatively stable due to the formation of coherent precipitates(Mg/Si clusters/GP zones) and the reduction in solute atom concentration in the Al matrix. The severe coarsening and decreased number density of the β″ phase during the over-aging stage result in a significant decrease in the hardness.

关键词： Al-Mg-Si alloy precipitation behavior strengthening mechanism strain field β″

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High-precision numerical modeling of the pro jectile launch and failure mechanism analysis of pro jectile-borne components

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Applied Mathematics and Mechanics(English Edition) 2025年第5期46卷 885-906页

作者： Xindan GUO Qiming LIU Xu HAN Tao LI Bin’an JIANG Canwei CAI State Key Laboratory of Advanced Design and Manufacturing Technology for Vehicle College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082China State Key Laboratory of Reliability and Intelligence of Electrical Equipment School of Mechanical EngineeringHebei University of TechnologyTianjin 300401China Artillery Ammunition Technology Laboratory PLA Army Academy of Artillery and Air DefenseHefei 230031China

As core components of precision-guided projectiles,projectile-borne components are highly susceptible to failure or even damage in complex high-overload environments,thereby significantly compromising launch reliability and ***,accurately characterizing the mechanical behavior of propellants remains challenging due to the limitations in the current internal ballistic theory and the constraints of large-scale artillery firing *** complicates the high-precision numerical modeling of projectile launch,and obstructs investigations into the failure mechanisms of projectile-borne ***,this paper identifies propellant parameters using the computational inverse method under uncertainty,further establishes high-precision numerical models of projectile launch,and explores the failure mechanisms of projectile-borne components in complex high-overload ***,a projectile launching experiment is meticulously designed and executed to obtain the breech pressure and muzzle ***,a general simulation model is built,and the powder burn model is used to simulate the ignition and ***,the propellant parameters are effectively identified with the computational inverse method by the combination of the experiments and simulations.A high-precision numerical model of projectile launch is modified with the parameters validated by another experiment,and the high-overload characteristics during projectile launch are thoroughly analyzed based on this ***,the high-overload characteristics of projectile-borne components are analyzed to elucidate the stress variation laws and to reveal the failure mechanisms influenced by time and spatial *** research provides an effective method for perfectly identifying propellant parameters and building high-precision numerical models of projectile ***,it provides significant guidance for the anti-high overload design and analysis of projectile-bo

关键词： projectile-borne component high-overload environment propellant parameter identification computational inverse technique failure mechanism

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A study of boundary conditions for pedestrian thorax impact test

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International Journal of vehicle Systems Modelling and Testing 2024年第2期18卷 120-133页

作者： Long, Yongcheng Liu, Yu Xiao, Yu Ruan, Zhisheng Xiao, Zhi Zhang, Guanjun Huang, Jing State Key Laboratory of Intelligent Vehicle Safety Technology Chongqing401122 China China Automotive Engineering Research Institute Co. Ltd. Chongqing401122 China Key Laboratory of Advanced Design and Manufacturing Technology for Vehicle Hunan University Changsha410082 China

Thorax injury is one of the main injuries during pedestrian impacts, and it is important to determine the boundary conditions for pedestrian thorax impactor tests. A series of virtual cases were built up to simulate the vehicle-pedestrian impact accidents. Then, the kinematic process was analysed during the vehicle-pedestrian impacts, and thorax impact parameters were extracted. Finally, the statistical characteristics of these impact parameters were obtained for thorax impactor tests. The results show that vehicle type affects the pedestrian impact kinematics and thorax impact parameters significantly. The range of thorax wrap-around distance is 928~1915 mm and 1018~1762 mm during sedan-pedestrian impact and SUV-pedestrian impact respectively. The average thorax impact speeds are about 5.8 m/s and 4.8 m/s in sedan-pedestrian impact and in SUV-pedestrian impact respectively. The average thorax impact velocity angles are 26.8° and 19.5° respectively. These results can provide the effective reference data for pedestrian thorax impactor tests. Copyright © 2024 Inderscience Enterprises Ltd.

关键词： Kinematics

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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

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design and performance analysis of the vacuum system for ion beam sputtering coating machine

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Vacuum 2025年 239卷

作者： Chen, Gengbiao Mo, Can College of Mechanical and Vehicle Engineering Changsha University of Science and Technology Changsha410114 China Key Laboratory of Safety Design and Reliability Technology for Engineering Vehicle Hunan Province Changsha410114 China

A high-performance vacuum system is a critical component of an ion beam sputtering (IBS) coating machine, as a clean, high-vacuum environment is essential for ensuring the quality and uniformity of sputtered coatings. This paper presents the design and performance analysis of a vacuum system tailored for IBS processes. A dual-chamber structure optimized for sputtering operations is proposed, and simulation results confirm stable gas flow and the absence of dead zones during main pump operation. Appropriate pump types are selected, and a vacuum system layout is developed to meet the stringent vacuum requirements of the coating process. To achieve accurate prediction of the system's evacuation time, a segmented pumping speed correction factor is introduced, enabling the construction of a sectional vacuum pumping model. Furthermore, a set of synchronized equipment operation commands is devised to realize efficient and automated vacuum pumping. The experimental results of the automated process closely match the model predictions. Compared to existing machines of the same type, the proposed system achieves ultimate vacuum nearly 2 h faster. © 2025 Elsevier Ltd

关键词： Vacuum pumps

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Injury severity analysis of electric bike crashes in Changsha, hunan province: taking different lighting conditions into consideration

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Transportation safety and Environment 2022年第3期4卷 43-54页

作者： Lin Hu Xiaotong Wu Xinting Hu Fang Wang Ning Wu School of Automotive and Mechanical Engineering Changsha University of Science and TechnologyChangsha 410114HunanChina Hunan Province Key Laboratory of Safety Design and Reliability Technology for Engineering Vehicle Changsha University of Science and TechnologyChangsha 410114HunanChina Institute for Traffic Engineering and Management Ruhr-University BochumD-44780 BochumGermany.

With the increasing use of electric bikes, electric bike crashes occur frequently. Analysing the influencing factors of electric bikecrashes is an effective way to reduce mortality and improve road safety. In this paper, spatial analysis is performed by geographicinformation system (GIS) to present the hot spots of electric bike crashes during daylight and darkness in Changsha, hunan province,China. Based on the Ordered Probit (OP) model, we studied the risk factors that led to different severities of electric bike *** results show that the main influencing variables include age, illegal behaviour, collision type and road factors. During daylightand darkness, elderly electric bike riders over the age of 65 years have a higher probability of fatal crashes. Not following trafficsignals and reverse driving are significantly related to the severity of riders’ injuries. In darkness, frontal collisions are significantfactors causing rider injury. In daylight, more serious crashes will be caused in bend and slope road segments. In darkness, roadswith no physically separated bicycle lanes increases the risk of riders being injured. Electric bike crashes are mainly concentratedin the commercial, public service and residential areas in the main urban area. In suburbs at darkness, electric bike riders are morelikely to be seriously injured. Adding protectionmeasures, such as improved lighting, non-motorized lane facilities and interventionstargeting illegal behaviour in the hot spot areas can effectively reduce the number of electric bike crashes in complex traffic.

关键词： Electric bike crash GIS Ordered Probit model daylight darkness

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Dynamic mesophase transition induces anomalous suppressed and anisotropic phonon thermal transport

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npj Computational Materials 2024年第1期10卷 239-248页

作者： Linfeng Yu Kexin Dong Qi Yang Yi Zhang Zheyong Fan Xiong Zheng Huimin Wang Zhenzhen Qin Guangzhao Qin State Key Laboratory of Advanced Design and Manufacturing Technology for Vehicle College of Mechanical and Vehicle EngineeringHunan UniversityChangsha410082People’s Republic of China College of Physical Science and Technology Bohai UniversityJinzhou121013People’s Republic of China Hunan Key Laboratory for Micro-Nano Energy Materials&Device and School of Physics and Optoelectronics Xiangtan UniversityXiangtan411105 HunanChina School of Physics and Microelectronics Zhengzhou UniversityZhengzhou450001China Research Institute of Hunan University in Chongqing Chongqing401133China Greater Bay Area Institute for Innovation Hunan UniversityGuangzhou511300 Guangdong ProvinceChina

The physical/chemical properties undergo significant transformations in the different states arising from phase ***,due to the lack of a dynamic perspective,transitional mesophases are largely underexamined,constrained by the high resource burden of first ***,usingmolecular dynamics(MD)simulations empowered by the machine-learning potential,we proffer an innovative paradigm for phase transition:regulating the thermal transport properties via the transitional mesophase triggered by a uniaxial force *** investigate the mechanical,electrical,and thermal transport properties of the two-dimensional carbon allotrope of Janus-graphene with strain-engineered phase ***,we found that the transitional mesophase significantly suppresses the thermal conductivity and induces strong anisotropy near the phase transition *** machine-learning-driven MD simulations,we achieved highprecision atomic-level simulations of *** results show that thermal vibrationinduced intermediate amorphous or interfacial phases induce strong and anisotropic interfacial thermal *** investigation not only endows uswith a novel perspective onmesophases during phase transitions but also enhances our holistic comprehension of the evolution of material properties.

关键词： thermal transition transport

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A Review of Intelligent vehicle Trajectory Tracking Control Methods Based on Overtaking Lane Change Scenarios 8th

A Review of Intelligent Vehicle Trajectory Tracking Control ...

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8th International Conference on Advances in Construction Machinery and vehicle engineering, ICACMVE 2023

作者： Yang, Dongzhao Hu, Lin Yi, Xiaojian Zhang, Xin School of Automotive and Mechanical Engineering Changsha University of Science and Technology Changsha410114 China School of Traffic and Transportation Engineering Changsha University of Science and Technology Changsha410114 China Hunan Key Laboratory of Safety Design and Reliability Technology for Engineering Vehicle Changsha University of Science and Technology Changsha410114 China

ISBN: (纸本)9789819718757

In order to achieve safe, comfortable, and stable control of lane-changing trajectories for intelligent vehicles, this paper reviews various trajectory tracking control methods for intelligent vehicles. Focusing on overtaking lane-changing trajectories, the paper provides a comprehensive review of research progress in PID, LQR, MPC, and SMC control methods both domestically and internationally. Striking a balance between addressing the challenges posed by non-integrity and multiple constraints of the vehicle, coping with the time-variability of the vehicle dynamics model, and ensuring the accuracy and computational efficiency of the vehicle model is essential for fostering the continuous development and enhancement of intelligent vehicle technology. © The Author(s) 2024.

关键词： Trajectories

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