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Applied Mathematics and Mechanics(English Edition) 2010年第9期31卷 1125-1140页

作者：刘又文谢超蒋纯志方棋洪 state key laboratory of advanced design and manufacturing for vehicle body Hunan University College of Mechanical and vehicle Engineering Hunan University Department of Physics and Electronic Information Engineering Xiangnan University

In this paper, the analytical solution of stress field for a strained reinforcement layer bonded to a lip-shaped crack under a remote mode III uniform load and a concentrated load is obtained explicitly in the series form by using the technical of conformal mapping and the method of analytic continuation. The effects of material combinations, bond of interface and geometric configurations on interfaciai stresses generated by eigenstrain, remote load and concentrated load are studied. The results show that the stress concentration and interfaciai stresses can be reduced by rational material combinations and geometric configurations designs for different load forms.

关键词： lip-shaped crack strained reinforcement layer concentrated load remote load eigenstrain interfacial stress

Three-dimensional numerical study of flow characteristics and membrane fouling evolution in an enzymatic membrane reactor

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Journal of Hydrodynamics 2018年第5期30卷 851-858页

作者： Xu-qu Hu Pai-qing Wu Xing-yi Wang Hai-cheng Zhang Jian-quan Luo state key laboratory of advanced design and manufacturing for vehicle body College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082China state key laboratory of Biochemical Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China

In order to enhance the understanding of the membrane fouling mechanism, the hydrodynamics of the granular flow in a stirred enzymatic membrane reactor is numerically investigated in the present paper. A three-dimensional Euler-Euler model, coupled with the k-ε mixture turbulence model and the drag function proposed by Syamlal and O＇Brien（1989） for the interphase momentum exchange, is built to simulate the two-phase（fluid-solid） turbulent flow. Numerical simulations of single-or two-phase turbulent flows at various stirring speeds are carried out. The numerical results agree very well with the published experimental data. Results include the distributions of the velocity, the shear stress and the turbulent kinetic energy. It is shown that the increase of the stirring speed not only enlarges the circulation loops in the reactor, but also increases the shear stress on the membrane surface and accelerates the mixing process for the granular materials. The time evolution of the volumetric function of the granular materials on the membrane surface can qualitatively explain the evolution of the membrane fouling.

关键词： Turbulent flow multiphase flow membrane fouling

Carbon foam with microporous structure for high performance symmetric potassium dual-ion capacitor

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Journal of Energy Chemistry 2020年第4期29卷 129-138页

作者： Yanhong Feng Suhua Chen Jue Wang Bingan Lu School of Physics and Electronics Hunan UniversityChangsha 410082HunanChina state key laboratory of advanced design and manufacturing for vehicle body Hunan UniversityChangsha 410082HunanChina

A novel carbon foam with microporous structure(CFMS),with the advantages of a simple fabrication process,low energy consumption,large specific surface area and high conductivity,has been prepared by a facile one-step *** addition,the carbon foam possesses suitable interlayer spacing in short range which is flexible to accommodate the deformation of carbon layer caused by the ion insertion and deinsertion at the charge and discharge ***,a low cost carbon-based symmetric potassium dual-ion capacitor(PDIC),which integrates the virtues of potassium ion capacitors and dual-ion batteries,is successfully established with CFMS as both the battery-type cathode and the capacitor-type *** displays a superior rate performance,an ultra-long cycle life(90%retention after 10000 cycles),and a high power density of 7800 W kg^-1 at an energy density of 39Whkg^-*** PDIC also exhibits excellent ultrafast charge and slow discharge properties,with a full charge in just 60 s and a discharge time of more than 3000 s.

关键词： Carbon foam Symmetric potassium-based dual-ion capacitor High energy/power density Ultrafast charge and slow discharge

Effects of working parameters on gasoline engine exergy balance

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Journal of Central South University 2013年第7期20卷 1938-1946页

作者： LIU Jing-ping FU Jian-qin FENG Ren-hua ZHU Guo-hui Research Center for advanced Powertrain Technology Hunan University Changsha 410082 China state key laboratory of advanced design and manufacturing for vehicle body (Hunan University) Changsha 410082 China

To improve the energy utilization efficiency of internal combustion （IC） engine, exergy analysis was conducted on a passenger car gasoline engine. According to the thermodynamic theory of IC engine, in-cylinder exergy balance model was built. The working processes of gasoline engine were simulated by using the GT-power. In this way, the required parameters were calculated and then gasoline engine exergy balance was obtained by programming on computer. On this basis, the influences of various parameters on exergy balance were analyzed. Results show that, the proportions of various forms of exergy in gasoline engine from high to low are irreversible loss, effective work, exhaust gas exergy and heat transfer exergy. Effective exergy proportion fluctuates with cylinder volumetric efficiency at full load, while it always increases with break mean effective pressure （BMEP） at part load. Exhaust gas exergy proportion is more sensitive to speed, and it increases with speed increasing except at the highest speed. The lower proportion of heat transfer exergy appears at high speed and high load. Irreversible loss is mainly influenced by load. At part load, higher BMEP results in lower proportion of irreversible loss; at full load, the proportion of irreversible loss changes little except at the highest speed.

关键词： gasoline engine exergy balance waste heat recovery thermal efficiency energy conservation

Trajectory tracking control of autonomous heavy-duty mining dump trucks with uncertain dynamic characteristics

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Science China(Information Sciences) 2023年第10期66卷 246-262页

作者： Liang CHEN Zhaobo QIN Manjiang HU Hongbo GAO Yougang BIAN Biao XU Xiaoyan PENG state key laboratory of advanced design and manufacturing for vehicle body Hunan University Wuxi Intelligent Control Research Institute of Hunan University Department of Automation University of Science and Technology of China

The proportion of mines using autonomous mining trucks is still very low at present. To promote the development of intelligent mining, it is urgent to proceed with the drive-by-wire modification to common mining trucks and design a motion control algorithm considering uncertain dynamic *** paper proposes a trajectory tracking control method for autonomous heavy-duty mining dump trucks(AHMDTs) with uncertain dynamic characteristics. In this method, a driving/braking force compensation algorithm based on an inverse dynamic model is designed to guarantee accurate longitudinal control with less control gain tuning. Using road curvatures, a modified rear-wheel position feedback control method is proposed to deal with reverse-path tracking, which can simultaneously reduce the lateral error and yaw angle error. A modified Stanley controller considering the collaborative preview based on speed and curvature is constructed to achieve accurate path tracking in the forward gear. Moreover, the proposed method focuses on the practice of trajectory tracking control in an open-pit mine condition with the adverse effects caused by uncertain vehicle dynamics, huge variable load, and large actuator lag. Real vehicle tests show that the proposed methodology can control AHMDTs with a low tracking error.

关键词： vehicle control trajectory tracking control driving/braking force compensation rear-wheel position feedback

Analysis of transient responses in a laminated piezoelectric cylindrical shell

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Science China(Physics,Mechanics & Astronomy) 2011年第1期54卷 143-149页

作者： HAN Xu GONG Shuang HE XiaoQiao JIANG Chao state key laboratory of advanced design and manufacturing for vehicle body College of Mechanical and Vehicle Engineering Hunan University Changsha 410082 China City University of Hong Kong Hong Kong China

A hybrid numerical method is proposed for analysis of transient responses in a multilayered piezoelectric cylindrical *** the present method,the associated equations of the displacement field and the electro-potential field are developed using an analytical-numerical *** piezoelectric cylindrical shell is discretized into layered annular elements along the wall thickness *** governing equations are determined by Hamilton's Principle considering the coupling between the elastic and electric field in each *** modal analysis and Fourier transformation with respect to the spatial cylindrical polar coordinates in the direction of wave propagation are introduced to formulate the displacement field and electro-potential field in the wave-number *** results of transient responses at any location can be obtained by performing an inverse Fourier *** transient responses of an actual piezoelectric cylindrical shell excited by a coupled electro-mechanical circular line load are investigated as a numerical *** computational results demonstrate the efficiency of the present method.

关键词： transient response piezoelectric material cylindrical shell

Fault-tolerant cooperative control for multiple UAVs based on sliding mode techniques

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Science China(Information Sciences) 2017年第7期60卷 54-66页

作者： Peng LI Xiang YU Xiaoyan PENG Zhiqiang ZHENG Youmin ZHANG College of Mechatronics Engineering and Automation National University of Defense Technology Department of Mechanical and Industrial Engineering Concordia University state key laboratory of advanced design and manufacturing for vehicle body Hunan University

This paper proposes a fault-tolerant cooperative control(FTCC) design approach for multiple unmanned aerial vehicles(UAVs), where the outer-loop control and the inner-loop fault accommodation are explicitly considered. The reference signals for the inner-loop of the follower UAV can be directly produced by resorting to a proportional control. In the presence of actuator faults, the estimation of the fault information can be completed within finite time. Moreover, the control of the inner-loop is reconfigured based on the fault information adaptation and sliding mode techniques, such that the deleterious effects due to failed actuators can be compensated within finite time. Simulations of UAV cooperative flight are conducted to illustrate the effectiveness of this FTCC scheme.

关键词： fault-tolerant cooperative control unmanned aerial vehicle actuator faults finite-time fault ac commodation

A Piezoelectric Screw Dislocation Interacting with an Elliptical Piezoelectric Inhomogeneity Containing a Confocal Elliptical Rigid Core

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Communications in Theoretical Physics 2011年第10期56卷 774-778页

作者：蒋纯志谢超刘又文 state key laboratory of advanced design and manufacturing for vehicle body Hunan University College of Mechanical and vehicle Engineering Hunan University Department of Physics and Electronic Information Engineering Xiangnan University

The electro-elastic interaction between a piezoelectric screw dislocation and an elliptical piezoelectric inhomogeneity, which contains an electrically conductive confocal elliptical rigid core under remote anti-plane shear stresses and in-plane electrical load is dealt with. The anaJytical solutions to the elastic field and the electric field, the interracial stress fields of inhomogeneity and matrix under longitudinal shear and the image force acting on the dislocation are derived by means of complex method. The effect of material properties and geometric configurations of the rigid core on interracial stresses generated by a remote uniform load, rigid core and material electroelastic properties on the image force is discussed.

关键词： complex variable method piezoelectric screw dislocation elliptical inhomogeneity elliptical rigidcore

Numerical investigations of the effects of blade shape on the flow characteristics in a stirred dead-end membrane bioreactor

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Journal of Hydrodynamics 2018年第6期30卷 1143-1152页

作者： Xu-qu Hu Xing-yi Wang Xiu-cheng Lei Xiang Qiu Lin-feng Chen state key laboratory of advanced design and manufacturing for vehicle body College of Mechanical and Vehicle Engineering Hunan University College of Science Shanghai Institute of Technology School of Naval Architecture and Ocean Engineering Jiangsu University of Science and Technology

Numerical simulations of turbulent flows in a stirred dead-end membrane bioreactor are performed by using the RNG k-? model based on the finite volume method with the software Fluent. Comparisons of numerical and experimental results confirm the reliability and the feasibility of the constructed model. The flow structures such as the wake flows and the circulation loops in the stirred flows are well simulated. An increase of stirring speed is proposed to minimize the low velocity region. The single vane stirrer is found to be beneficial for biological separations. Results suggest that the increase of the vane number can enhance the mixing effect in the flow domains. However, a circular disk stirrer goes against the formation of vertical circulations. The six-vane stirrer is found to be able to provide a uniform distribution of the high shear stress.

关键词： Turbulent flow stirred flows membrane fouling membrane bioreactor

Effects of grain boundary on irradiation-induced zero-dimensional defects in an irradiated copper

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Applied Mathematics and Mechanics(English Edition) 2022年第2期43卷 233-246页

作者： Jing PENG Shiyong CUI Yuanyuan TIAN Qihong FANG Jia LI P.K.LIAW state key laboratory of advanced design and manufacturing for vehicle body College of Mechanical and Vehicle EngineeringHunan UniversityChangsha410082China Department of Materials Science and Engineering The University of TennesseeKnoxvilleTennessee37996U.S.A

Grain boundaries(GBs)can serve as effective sinks for radiation-induced defects,thus notably influencing the service performance of ***,the effect of GB structures on the zero-dimensional defects induced by irradiation has not been fully ***,the evolution of cascade collision in the single-crystal(SC),bicrystalline(BC),and twinned crystalline(TC)copper is studied by atomic simulations during *** spatial distributions of vacancies and interstitials are closely related to the GB at a certain primary knock-on atom(PKA)*** with the TC,the BC displays a more obvious segregation of the interstitial atoms near GB,due to the characteristic of the greater interstitial binding *** evolution of Frenkel pairs is more sensitive to the change of the GB position in the BC.A more prominent defect annihilation rate is caused by the effect of the GB than that of the twin boundary(TB).The marked secondary emission phenomenon has been observed in the BC,which promotes the formation of an inverted pagoda-like defect *** are similar sub-conical defect distributions and microstructures induced by cascade collision in the TC and the *** has been found that the influence range of the GB is wider in the ***,the average flow stress of the irradiated copper is quantitatively calculated by establishing a physical strengthening *** contribution of vacancy to the average flow stress in the irradiated BC and TC is obvious than that in the SC,due to the formation of many *** study provides a theoretical basis for further understanding and customization of the metal-based equipment with good radiation resistance.

关键词： irradiation cascade collision grain boundary(GB) interstitial and vacancy molecular dynamics(MD)simulation physical strengthening model