Zheng X.,Chinese Naval Aeronautical Engineering Academy |
Hou Z.,Airborne |
Han W.,Airborne |
Li J.,Naval Flying Academy
Jixie Gongcheng Xuebao/Journal of Mechanical Engineering | Year: 2012
The dynamic character and control of very low frequency(VLF) trailing antenna on a aircraft is one of most important problems which needs to research. The steady dynamic is the base of the dynamic character and control of the VLF trailing antenna. The mathematics model based Newton law of the trailing antenna is founded, and solved via a shooting technique. The influences of the angle of bank and the velocity of aircraft to the non-dismensionalization end radius and verticality are researched. The result shows that under the low drag, for certain ranges of the angle of bank and the velocity, the equilibrium solution is multivolume; under certain ranges of air drag, it is possible to descend the velocity of the aircraft and increase the bank angle to improve the verticality of the antenna. But it's impossible to increase the mass of the drogue only to improve the verticality of the antenna. © 2012 Journal of Mechanical Engineering.
Xu L.,Chinese Naval Aeronautical Engineering Academy |
Xu L.,Naval Flying Academy |
Bian G.,Chinese Naval Aeronautical Engineering Academy |
Hu J.,Chinese Naval Aeronautical Engineering Academy
Applied Mechanics and Materials | Year: 2012
The objective of this work was to evaluate life prediction methodologies involving fretting fatigue of TA15 materials with advanced surface treatments. Fretting fatigue tests were performed on TA15 specimens with and without advanced surface treatments. Laser shock processing and low plasticity burnishing have been shown to produce deep compressive residual stresses with relatively little cold work. Testing showed these advanced surface treatments improved fretting fatigue strength by approximately 50 %. This work presents a mechanics based lifing analysis of these tests that takes into account the local plasticity and the redistribution of residual stresses due to the contact loading. The use of superposition of the residual stresses into the contact stress analysis results in unconservative crack growth life predictions. Finite element analyses were conducted to predict the redistribution of residual stresses due to the contact loading. The redistributed residual stresses were used to make improved crack growth life predictions when possible. The results showed very little redistribution of residual stresses for the advanced surface treatments. © (2012) Trans Tech Publications.
Sun G.,Changchun University |
Qi X.,Changchun University |
Zhang Y.,Naval Flying Academy
Proceedings of the 2011 Chinese Control and Decision Conference, CCDC 2011 | Year: 2011
Rough set theory is mainly used for analyzing, processing fuzzy and uncertain information and knowledge, and mainly used for the aspect of fault diagnosis, but the theory is basically implemented by software. The article makes use of the advantages of hardware, put forward A FPGA-based implementation of Rough Set Theory, the method effectively improves the speed of data process, reduction and rule extraction, in addition, the method has a strongly engineering practically, and provide a new method for technology research of fault diagnosis based on hardware. © 2011 IEEE.
Wu M.,Naval Flying Academy
Xitong Fangzhen Xuebao / Journal of System Simulation | Year: 2015
Based on the known probable moving course of submarine targets, and the actual searching process of anti-submarine airplane, to search the target in the finite domain, the wind factor to affect searching process was analyzed. The arc-spiral searching model of dipping sonar and submarine moving models were built. In the factor of given ocean environments, the experimental results simulated and analyzed the arc-spiral searching course of dipping sonar. The experimentation compared and analyzed the influence of searching probabilities on curve searching, sector searching, and arc-spiral searching manners. The experimental results indicate that the searching probability of arc-spiral searching manner of dipping sonar is better than curve and sector searching manners. © 2015, The Editorial Board of Journal of System Simulation. All right reserved.
Liu F.-M.,Harbin Engineering University |
Qian D.,Harbin Engineering University |
Liu C.-H.,Harbin Engineering University |
Liu C.-H.,Naval Flying Academy
Kongzhi yu Juece/Control and Decision | Year: 2012
In this paper, an artificial physics optimized particle filter(APO-PF) is proposed. Artificial physics optimization (APO) is incorpoarted into resampling process to deal with the sample degeneration and impoverishment of generic particle filter(PF). Virtual force model of the APO specifies that particles have mutually attractive and repulsive force. Through optimization, the APO can distribute particles in high likelihood area, and the sample degeneration is reduced. Synchronously, the APO makes particles contain each other in the motion process, ulteriorly formats better coverage to posterior probability density, which improves estimation performance, particle overlap is avoided and diversity of particle is also maintained. The simulations are performed to show the effectiveness of the algorithm, and the results show that the estimation performance and robustness of the proposed algorithm are superior to that of the generic PF.
Ding W.,Naval Flying Academy |
Yu X.-C.,Naval Flying Academy |
Tang Y.-H.,Naval Flying Academy
Gaoya Dianqi/High Voltage Apparatus | Year: 2011
The electron energy conversion processes were analyzed through calculating the established dielectric barrier discharge kinetic model, and the foundation was laid for grasping the mechanism of plasma assisted combustion. The results showed that the electron energy distribution function of dielectric barrier discharge plasma was mainly affected by the reduced field. With the change of the reduced field, electron energy loss in the proportion of different collisions types was different, and electron energy was primarily lost in the excited and dissociated collisions with N 2 and O 2 moleculars with the commonly used reduced field which between 100 Td to 300 Td. For air and stoichiometric mixture of air and methane dielectric barrier discharge, about 50% and 126% of the discharge energy was used to heat the gas respectively after the dischargeabout1ms.
Sun H.,Shijiazhuang Mechanical Engineering College |
Ma J.,Shijiazhuang Mechanical Engineering College |
Sheng L.,Shijiazhuang Mechanical Engineering College |
Li W.,Naval Flying Academy |
Wu D.,Shijiazhuang Mechanical Engineering College
Applied Mechanics and Materials | Year: 2012
A coupled constitutive model of viscoplasticity and ductile damage for penetration problems has been deduced. The model proposed by Lemaitre was based on the continuum damage mechanics. In the model, large strain, high strain-rate, thermal softening and damage evolution were taken into account. At the meanwhile, Von Mises yield criterion, Johnson-Cook hardening model and Johnson-Cook fracture strain model were adopted. The model was implemented in the explicit finite element code Abaqus\Explicit through the Vumat subroutine by using an efficient explicit time integration algorithm. Based on the model, the rotating band's engraving process was simulated, at the same time the influence of the stress state on damage evolution and the thermal softening effect was discussed. An effective way to simulate the fire process of gun was afforded. © (2012) Trans Tech Publications.
Liu T.,Airborne |
Zhao G.-R.,Yantai Naval Aeronautical and Astronautical University |
Li J.-X.,Naval Flying Academy |
Xu K.-W.,Yantai Naval Aeronautical and Astronautical University
Beijing Gongye Daxue Xuebao/Journal of Beijing University of Technology | Year: 2012
The coning error owns new existing form and characteristics in gyroscope-free strap-down inertial navigation system (GFSINS). For GFSINS cannot directly give out angle increment when adopting four sub samples equivalent rotation vector algorithm, the getting method was designed and optimized to improve the efficiency of gesture updating. Finally, the coefficients in the calculating formula of equivalent rotation vector was optimized by chaos particle swarm optimization algorithm. Simulation result shows that it can effectively eliminate the influence of coning error and improve the navigation precision.
Yang M.,Yantai Naval Aeronautical and Astronautical University |
Bi Y.,Yantai Naval Aeronautical and Astronautical University |
Chen Y.,Yantai Naval Aeronautical and Astronautical University |
Xu L.,Naval Flying Academy
Proceedings of 2011 IEEE International Conference on Intelligence and Security Informatics, ISI 2011 | Year: 2011
To study the influence factors of aluminum alloy Fretting fatigue life, the global finite element model is employed. The effectiveness of the model is validated according to the comparison of analytical solutions and numerical solutions. A new fretting fatigue life prediction model has been proposed base on friction work. The rationality and effectiveness of the model are validated according to the contrast of experiment life and predicting life. At last influence factor on fretting fatigue life of aerial aluminum alloy LY12CZ is investigated with the model. The results reveal that fretting fatigue life decreases monotonously with the increasing of normal load and then becomes constant at higher pressures. At low normal load, fretting fatigue life increases with the incline of pad radius. At high normal load, however, the fretting fatigue life is unrelated with the fretting pad radius. The bulk stress amplitude has the dominant effect on fretting fatigue life. The fretting fatigue life diminishes as the bulk stress amplitude increases. © 2011 IEEE.
Li W.,Ordnance Engineering College |
Li W.,Naval Flying Academy |
Ma J.-S.,Ordnance Engineering College |
Sun H.-Y.,Ordnance Engineering College |
And 2 more authors.
Zhendong yu Chongji/Journal of Vibration and Shock | Year: 2011
Based on the elastic-plastic contact finite element theory, inertial bayonet-chamber process of a projectile was analyzed, and its finite element model was built. The inertial bayonet-chamber process with 1~4 m/s was computed, the elastic-plastic deformation of the band and the dynamic response of the projectile was obtained and the influence of the friction coefficient on the computed results of the inertial bayonet-chamber process was analyzed.