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International Journal of Smart and Nano materials 2023年第2期14卷 139-154页

作者： Ying Wang Hongmei Li Shaowei Lu Xingmin Liu Wei Li Xiaoqiang Wang Lu Zhang Qingxuan Wang college of aerospace engineering Shenyang Aerospace University(SAU)ShenyangChina college of material Science and engineering Shenyang Aerospace University(SAU)ShenyangChina

Composite structures are sensitive to impact damage in practical engineering.Electric resistance change method(ERCM)is an ideal technique for damage monitoring of composite structures.Due to the anisotropy of fiber-resin matrix composites,impact location monitoring is difficult,and research on impact location of fiber composite laminates(FRPs)is limited.A preparation method of MXene/CNT/CuNps thin film sensor is proposed.According to the modeling simulation and theoretical calculation,the resistance change characteristics of the thin film sensor are obtained,the relationship between the impact distance and the resistance change is established,and the sensor array is designed.A three-point localization algorithm and a weight function compensation localization algorithm are proposed,which can improve the imaging accuracy of the impact position.The impact point location was observed and analyzed using ultrasonic C-scan technology.The results show that the weight function compensation positioning algorithm can accurately locate the impact of the composite structure,and the error in the X direction is 7.1%,the error in the Y direction is 0.03%,which verifies the effectiveness of the method.

关键词： Electric resistance change method Mxene/CNT/CuNps film sensor damage localization Weighting function

Optimal aeroassisted symmetric transfer between coplanar elliptical orbits

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Journal of Systems engineering and Electronics 2013年第2期24卷 261-271页

作者： Jun Fu Hong Cai Shifeng Zhang College of Aerospace and Material Engineering National University of Defense Technology

The problem of optimal aeroassisted symmetric transfer between elliptical orbits is concerned.The complete trajectory is assumed as consisting of two impulsive velocity changes at the beginning and the end of an interior atmospheric subarc,where the vehicle is controlled via the lift coefficient and thrust.The corresponding dynamic equations are built and bounded controls are considered.For the purpose of optimization computation,the equations are normalized.In order to minimize the total fuel consumption,the geocentric radius of initial elliptical transfer orbital perigee and controls during atmospheric flight should all be optimized.It is an optimal control problem which involves additional parameter optimization.To solve the problem,a two-level optimization method denoted by ＂genetic algorithm ＋ Gauss pseudospectral method＂ is adopted：the genetic algorithm is used for parameter optimization and the Gauss pseudospectral method is used for optimal control problems.The flow chart of simulation is given.On this basis,the issue of more realistic modeling with two finite-thrust subarcs in the nonatmospheric part of the trajectory is simultaneously addressed.The orbital transfer problem is transformed to three continuous optimal control problems,and the constraints at different times are given,which are respectively solved by using the Gauss pseudospectral method.The obtained numerical results indicate that the optimal thrust control is of bangbang type.The minimum-fuel trajectory in the atmosphere consists of aeroglide,aerocruise and aeroglide.They are compared with the results of pure impulsive model,and the conclusions that a significant fuel saving will be achieved by synergetic maneuver are drawn.

关键词： aeroassisted orbital transfer Gauss pseudospectral method optimal control two-level optimization genetic algorithm synergetic maneuver

Preface of“Trends in Nanomaterials and Nanocomposites:Fundamentals,Modelling and Applications”--Festschrift in honor of Prof Yiu-Wing Mai's 75th birthday

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Nano materials Science 2022年第2期4卷 61-63页

作者： Long-Cheng Tang Shao-Yun Fu college of material Chemistry and Chemical EngineeringKey Laboratory of Organosilicon Chemistry and Material Technology of MoEHangzhou Normal UniversityHangzhou311121PR China college of aerospace engineering Chongqing UniversityChongqing400044China

Prof.Yiu-Wing Mai has made many significant and sustained contributions pushing the boundaries of science and engineering of advanced materials,especially nanomaterials and nanocomposites in recent two decades.This Festschrift on“Trends in Nanomaterials and Nanocomposites:Fundamentals,Modelling and Applications”is dedicated to his 75th birthday in recognition of his influential research on nanomaterials and nanocomposites.The range of topics covered represents a cross-section of the scientific interests of Prof.Mai and his collaborators.We would like to thank Prof.Jian Lu,Editor-in-Chief of Nano materials Science,for publishing this special issue.

关键词： composites sustained thank

Rheological Behaviors and Processing Windows of Low Viscosity Epoxy Resin for VIMP

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Journal of Wuhan University of Technology(materials Science) 2011年第5期26卷 931-934页

作者：刘卓峰 College of Aerospace and Material Engineering National University of Defense Technology

The chemorheological behaviors of a low viscosity epoxy resin system （Huntsman 1564/3486） for vacuum infusion moulding process （VIMP） were studied with viscosity experiments.The dual-Arrhenius rheological model and the engineering viscosity model were established and compared with the experimental data.The result showed that the viscosity in the earlier stage calculated by dual-Arrhenius model were smaller than the experimental data,while the data calculated by the engineering model were larger.Combining the two models together can predict the rheological behaviors of the resin system in a more credible manner.The processing windows of the resin system for VIMP were determined based on the two models.The optimum processing temperature is 30-45 ℃.

关键词： vacuum infusion molding process（VIMP） epoxy resin rheological behaviors

Analysis and Testing of Microvibrations Produced by Momentum Wheel Assemblies

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Chinese Journal of Aeronautics 2012年第4期25卷 640-649页

作者： ZHOU Weiyong LI Dongxu LUO Qing LIU Kun College of Aerospace and Material Engineering National University of DeJense TechnologyChangsha 410073China

The microvibrations produced by momentum wheel assemblies（MWA） can degrade the performance of instruments with high pointing precision and stability on spacecraft.This paper concentrates on analyzing and testing the microvibrations produced by MWA.We analyze the disturbance sources produced by mass imbalance,structural mode,bearing irregularity and nonlinear stiffness,and random noise;then,test a well-balanced MWA by a highly sensitive measurement system consisting of a Kistler table and an optical tabletop.The results show that the test system has a resolution of less than 0.003 N in the frequency range of 3-300 Hz.The dynamic imbalance of the MWA cannot excite the radial rocking mode,but there are dynamic amplifications when the poly-harmonic disturbances intersect with the structural modes.Especially at high rotational speed（〉3 000 rev/min）,the main disturbance sources of the MWA come from the bearing irregularity interacting with radial translation mode in the high frequency range.Thus,bearing noise deserves more attention for the well-balanced MWA,and alternative of high quality bearings are proposed to reduce the microvibrations.

关键词： momentum wheel assemblies microvibration bearing irregularity mass imbalance vibration analysis

Annealing effect of platinum-incorporated nanowires created by focused ion/electron-beam-induced deposition

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Chinese Physics B 2014年第8期23卷 586-590页

作者：方靖岳秦石乔张学骜刘东青常胜利 college of Science National University of Defense Technology College of Aerospace and Material Engineering National University of Defense Technology

Focused ion-beam-induced deposition （FIBID） and focused electron-beam-induced deposition （FEBID） are conve- nient and useful in nanodevice fabrication. Since the deposition is from the organometallic platinum precursor, the con- ductive lines directly written by focused ion-beam （FIB） and focused electron-beam （FEB） are carbon-rich materials. We discuss an alternative approach to enhancing the platinum content and improving the conductivity of the conductive leads produced by FIBID and FEBID, namely an annealing treatment. Annealing in pure oxygen at 500 ℃ for 30 min enhances the platinum content values from ~ 18% to 30% and ~ 50% to 90% of FIBID and FEBID, respectively. Moreover, we find that thin films will be formed in the FIBID and FEBID processes. The annealing treatment is helpful to avoid the current leakage caused by these thin films. A single electron transistor is fabricated by FEBID and the current-voltage curve shows the Coulomb blockade effect.

关键词： electron-beam-induced deposition ion-beam-induced deposition annealing current leakage single electron transistor

Investigation into Pilot Handling Qualities in Teleoperation Rendezvous and Docking with Time Delay

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Chinese Journal of Aeronautics 2012年第4期25卷 622-630页

作者： ZHOU Jianyong ZHOU Jianping JIANG Zicheng LI Haiyang College of Aerospace and Material Engineering National University of Defense TechnologyChangsha 410073China

Teleoperation rendezvous and docking can be used as a backup for autonomous rendezvous and docking（RVD） for an unmanned spacecraft when the autonomous system is failure or for guiding the chaser docking with an uncooperative target.The theoretical model for analyzing the handling qualities in teleoperation RVD process is established based on the previous studies conducted by National Aeronautics and Space Administration（NASA）.The predictive factor is introduced to describe the pilot＇s predictive ability in the teleoperation tasks with time delay,which interrelates with the skills of a pilot and the predictive assist approach used in the tasks such as the predictive display method.Based on the semi-physical simulation system in our laboratory,900 experiments at two levels of time delay are carried out by 18 volunteers for validating the established model.The experimental results demonstrate the correctness of the theoretical model and indicate that a skilled pilot has a predictive ability of approximately 0.9 in teleoperation RVD tasks.The theoretical analysis shows that the handling qualities are greatly affected by the time delay and the predictive factor,and it is impossible to achieve a teleoperation RVD task for the skilled pilot when the time delay is larger than 9.0 s.

关键词： teleoperation rendezvous and docking handling quality theoretical model time delay experimental validation

Temporal evolution of the optical path difference of a supersonic turbulent boundary layer

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Chinese Physics B 2013年第1期22卷 231-236页

作者：高穹易仕和姜宗福何霖谢文科 college of Photon-electron Science and engineering National University of Defense Technology College of Aerospace and Material Engineering National University of Defense Technology

The density distribution of a supersonic turbulent boundary layer is measured with the nanoparticle-based planar laser scattering technique, and the temporal evolution of its optical path difference （OPD） in a short time interval is characterized by proper orthogonal decomposition （POD）. Based on the advantage of POD in capturing the energy of a signal, a temporal evolution model is suggested for the POD coefficients of the OPD. In this model, the first few coefficients vary linearly with time, and the others are modeled by Gaussian statistics. As an application, this method is used to compute the shortexposure optical transfer function.

关键词： aero-optics supersonic turbulent boundary layer optical transfer function

High power nano-LiMn_2O_4 cathode materials with high-rate pulse discharge capability for lithium-ion batteries

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Chinese Physics B 2011年第2期20卷 532-537页

作者：陈颖超谢凯盘毅郑春满王华林 Department of material engineering and Applied Chemistry College of Aerospace and Materials EngineeringNational University of Defense Technology

Nano-LiMn2O4 cathode materials with nano-sized particles are synthesized via a citric acid assisted sol-gel route. The structure, the morphology and the electrochemical properties of the nano-LiMn204 are investigated. Compared with the micro-sized LiMn2O4, the nano-LiMn2O4 possesses a high initial capacity （120 mAh/g） at a discharge rate of 0.2 C （29.6 mA/g）. The nano-LiMn2O4 also has a good high-rate discharge capability, retaining 91% of its capacity at a discharge rate of 10 C and 73~ at a discharge rate of 40 C. In particular, the nano-LiMn2O4 shows an excellent high-rate pulse discharge capability. The cut-off voltage at the end of 50-ms pulse discharge with a discharge rate of 80 C is above 3.40 V, and the voltage returns to over 4.10 V after the pulse discharge. These results show that the prepared nano-LiMn2O4 could be a potential cathode material for the power sources with the capability to deliver very high-rate pulse currents.

关键词： lithium-ion batteries lithium manganese oxide high-rate pulse discharge

Strain analysis of nonlocal viscoelastic Kelvin bar in tension

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Applied Mathematics and Mechanics(English Edition) 2008年第1期29卷 67-74页

作者：赵雪川雷勇军周建平 College of Aerospace and Material Engineering National University of Defense Technology

Based on viscoelastic Kelvin.model and：nonlocal relationship of strain and stress, a nonlocal constitutive relationshila of viscoelasticity is obtained and the strain response of a bar in tension is studied, By transforming governing equation of the strain analysis into Volterra integration form and by choosing a symmetric exponential form of kernel function and adapting Neumann series, the closed-form s.olution of strain field of the bar is obtained.： The creep process of the bar is presented： When time approaches infinite, the strain of bar is equal to the one of nonlocal elasticity

关键词： nonlocal theory Kelvin viscoelasticity Neumann series bar strain analysis