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2008 Vol. 34, No. 8

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Modeling and simulation of rapid transfer alignment for SINS
Gong Xiaolin, Fang Jiancheng, Guo Lei
2008, 34(8): 865-868.
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Aiming at the problem of rapid and accurate transfer alignment for the space weapon strapdown inertial navigation system (SINS), the error model of weapon SINS was established and the errors of inertial elements were considered. The attitude matching was selected, and the measurement equation of the attitude error between space weapon SINS and satellite was deduced based on the principle of attitude transfer alignment. Based on these, the filter model of space weapon SINS was established and a rapid Kalman filter was designed for the space weapon-s transfer alignment. The results of simulation show that this model is efficient on filter-s convergence and precision. The alignment accuracy is similar to the one attitude measurement system of satellite have, and furthermore, the constant errors of gyros on space weapon can be calibrated.
Redundancy control of direct-drive-valve servo system
Yu Yongqiang, Guo Hong, Xie Zhanming
2008, 34(8): 869-872.
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A novel neural network adaptive sliding mode control strategy was proposed, which was applied to ensure tracking capability to direct-drive-valve (DDV) servo system in the presence of degrading redundancy. A radial basis function neural network (RBFNN) was adopted to realize sliding mode control. By means of compensating varieties of the system with adaptive learning algorithm, the control based on RBFNN decreased the tracking error and enhanced the robustness. Meanwhile, a proportional-derivative (PD) controller was designed as the other parallel control part, which improved the convergence of RBFNN, and enhanced the stability of system. Simulation results show that the proposed control scheme solves the problems brought by the degrading of redundancy effectively. It possesses better tracking performance than switching proportional- integral-derivative (PID) control, and can be designed easily.
Using the robust control method to control the vibration of piezoelectric laminated plates
Hu Juxi, Qiu Zhiping
2008, 34(8): 873-877.
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The piezoelectric laminated plate were researched, which posses the uncertain system parameters, and considering the steady-state behavior and transient performance of the piezoelectric laminated plate. On the foundation of the model deflation, the author used the robust controller to bring the piezoelectric laminated plate have the robustness for the parameter perturbation, and favorable inhibitory action about the disturbance import. The robust control of the piezoelectric lamination plate were realized, and the vibration amplitude were made to be quickly and exactly under control. A kind of algebra method for solve the controlling problem of the piezoelectric laminated plate vibration that with uncertain parameters was supplied.
Foreshowing study of dynamic environment on the sphere-cone-cylinder reentry vehicles
Hong Jie, Gao Jinhai, Ma Yanhong, Zhu Bin
2008, 34(8): 878-882.
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The stable and fluctuating pressure distribution on the surface of the sphere-cone-cylinder reentry vehicle was investigated in the supersonic and hypersonic flow field. Computation fluid explorer(CFX )was used to model the grid which had been analysis of three-dimension steady flow and unsteady flow field. Meanwhile the new engineering method of the surface of the sphere-cone-cylinder reentry vehicle was given . Then, the theory and estimation method was compared , which tested and verified the feasibility and applicability of this method . The effect of fluctuating pressure distribution on the surface made by Mach number and attack angle was researched. Taking advantage ANSYS, the model of dynamic analysis of reentry vehicle in missile-s head was created. Meanwhile , according to the method fluctuating pressure and random vibration theory of reentry vehicle, the root mean square(RMS) and power spectral density(PSD) of acceleration response was presented by spectrum analysis, which was very practical and applicable.
Reliability assessment model and application for aero-engine based on criticality method
Wang Dawei, Ma Yanhong, Hong Jie
2008, 34(8): 883-886.
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The reliability assessment model based on criticality method was proposed for aero-engine reliability evaluation. Various aero-engine fault samples which affected the normal work were considered in this model. The entire appearance fault sample was classified by the targets of aero-engine safety, performance, tasks and maintenance. A corresponding distribution statistical model was founded on the failure mechanism of fault samples, and the reliability targets were statistically analyzed by using distribution method and twi-distribution method. English aero-engines and Chinese ones which are with same types were statistically analyzed by this model .Time Tracking analysis method of fault samples based on cumulation working hours and calendar time was discussed , and the time effectiveness of fault samples was considered.
Analysis of the mechanics for ski-jump takeoff
Wang Weijun, Guo Linliang, Qu Xiangju
2008, 34(8): 887-890.
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The matching between parameters of ski-jump ramp and flying performance/quality of carrier-based aircraft was analyzed based on the dynamic process of force polygon and the effect of ski-jump ramp on the pitch rotation of aircraft, and the building-up mechanism of the angle of attack at the initial stage after aircraft leaving the ramp at low speed was demonstrated. The building-up of the angle of attack results from following three aspects: The ramp provides the aircraft a positive pitch rate, which increases the angle of attack; When the nose landing gear leaves the ramp and the main landing gears do not, pitch down moment is provided by the ramp reacting force upon the main landing gears, and the pitch rate is decreased; While the aircraft just leaves the ramp, the lift cannot balance the gravity, so the acceleration vector points forward and downward, the speed vector is deflexed, and the angle of attack is increased. Simulation on the multi-bodies dynamic system of carrier/aircraft/landing gears shows that the above analysis is reasonable.
Numerical prediction for the elastic properties of three dimensional and five directional braided composites
Li Diansen, Liu Zixian, Lu Zixing
2008, 34(8): 891-895.
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The finite element model is established based on the micro-structure of three dimensional and five directional braided composites and the assumption of the braiding yarn with the hexagon section and the axial yarn with the square section and the analysis of geometrical relationship of yarns in three dimensions. The elastic constants of three dimensional and five directional braided composites are calculated by the finite element method and compared with the corresponding results of three dimensional and four directional braided composites. The influences of the braiding angle and fiber volume fraction on the elastic constants are also analyzed. In addition, the predictions were compared with the experiment results which verified the validity of the finite element analysis. The results show that three dimensional and five directional braided composite has good mechanical properties and it improves the axial mechanical performance of the material by joining the axial yarns.
Impacts of imperfect receivers on complex correlation of 2D aperture synthesis microwave radiometer
Zhao Feng, Miao Jungang, Wan Guolong, Xue Yong
2008, 34(8): 896-899.
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The impacts of receivers- rectangular frequency response imperfections on the complex correlation measurement of 2D aperture synthesis microwave radiometer were presented. These imperfections include center frequency imbalance, bandwidth imbalance, group delay imbalance, phase imbalance of local oscillator and in-band ripple. The analytical results show that the phase error of complex correlation mainly comes from group delay imbalance, phase imbalance of local oscillator, and that the amplitude error of complex correlation mainly comes from center frequency imbalance, bandwidth imbalance,group delay imbalance and in-band ripple. These amplitude errors and phase errors can be corrected by correlated noise injection. The complex correlation errors of Beihang university,2-dimensional(BHU-2D) aperture synthesis microwave radiometer before and after system correction were estimated.
Effect of ice geometry to airfoil performance using neural networks prediction
Yuan Kungang, Cao Yihua
2008, 34(8): 900-903.
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The ice accretion geometric characteristics have complex effects on airfoil aerodynamic coefficients. By using levenberg-marguardt(LM) learn algorithm of back-propagation (BP) network, several neural networks were established to get correlations between typical glaze ice geometry (ice horn leading-edge radius, ice height and ice horn position on airfoil surface) and airfoil aerodynamic coefficients. The neural network was also generated for predicting the maximum lift coefficient in typical ice accretion geometric parameters. In addition, the neural network that used to get the relationship of airfoil hinge moment coefficient and ice geometric was obtained to predict the angle of attack stall. The simulation results of neural networks have high coherence with experimental data and can predict coefficients at non-experimental conditions. The horn location on airfoil surface has the most severe effects on airfoil coefficients. The hinge moment coefficient breaks before the stall of angle of attack and can be used for predicting stall more safely.
Application of new defected EBG structure in microstrip antenna
Lü Shanwei, Zhao Xiaoji, Feng Wenquan, Zhang Jianglin
2008, 34(8): 904-906.
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In order to meet some specific application requirements for microstrip patch antenna in navigation and communication project, a novel defected electromagnetic band-gap (EBG) and ground structure designed for improving the performance of traditional microstrip patch antenna was presented. For building this structure, several EBG elements were firstly placed near a usual circularly polarized square microstrip patch with two opposite corners cut. This can enhance the resonance frequency and change only slightly the bandwidth of the patch antenna. Then a thin square metal layer was cut off from four sides of the ground plane to forms a square loop of dielectric layer. The results of numerical simulation show that the new structure is able to improve the performance of antenna gain including total and low elevation situation, and the microstrip patch antenna equipped with this structure can be treated as a dual-frequency antenna.
Experimental investigation of kerosene supersonic combustion based on cavity flameholder
Wang Liao, Wei Baoxi, Zhang Chengliang, Xu Xu
2008, 34(8): 907-910.
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Experimental investigation of kerosene supersonic combustion was performed on direct-connect supersonic combustion test facility by using four different configurations of cavity flameholders and multi-diameter kerosene injectors. Kerosene equivalence ratio varies from 0.24 to 1.32 and polite hydrogen equivalence ratio was 0.53. Successful ignition and sustain combustion were achieved in multi-test conditions. The distribution of wall static pressure was measured to validate the combustion performances under different test conditions. The experimental results show the four cavity flameholders used in the test have excellent flame holding effects. The configuration of cavity has great influence on the ignition of kerosene in supersonic airstream.Larger length depth ratio was better for the kerosene ignition, and with several cavities, kerosene can achieve self-ignition without pilot hydrogen. equivalence ratio is the most important influencing factor of kerosene combustion capabilities. At same kerosene equivalence ratio, higher injection pressure can improve the kerosene combustion effects.
Fabrication and electricity properties of metal covered acrylate rubber microspheres by electroless plating
Gao Dali, Zhan Maosheng
2008, 34(8): 911-915.
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Electroless copper plating on acrylate rubber (ACM) microspheres of micron scale was studied. By introducing a reaction control method, the continuously and uniformly covered ACM conductive microspheres with low density and core-shell structure were achieved. The morphology and composition of Cu coatings and the electrical properties of the Cu-coated ACM microspheres were investigated. It was found that Cu can be plated on the surface of ACM microspheres by electroless plating. The reaction process of electroless copper plating can be controlled by adjusting the OH-additional amounts, thus to control the morphology of Cu coatings. The Cu-coated ACM microspheres all present resistance characters that the volume resistivity declines with pressure, but remains constant with electrifing time. And the Cu-coated ACM microspheres present the special resistance behaviors with the rising of temperature.
Aging treatment of FeNiCr/NiAl-TiC composite coatings produced by thermit process
Wang Genlong, Xi Wenjun
2008, 34(8): 916-919.
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The FeNiCr/NiAl-TiC composite coatings were prepared by thermit reaction process in a carbon steel pipe. Using scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), and energy dispersive spectrum (EDS), the microstructure of the composite coatings and effects of aging treatment on the microstructure were investigated. Results show that the FeNiCr/NiAl-TiC composite coatings are composed of titanium carbide (TiC), intermetallic compound NiAl and ferrite (α-FeNiCr). The alloy matrix consists of NiAl and α-FeNiCr in which the grain size of the NiAl is about 100nm. After aging treatment, the phase constituent of the coatings doesn-t change. The shape and size of TiC particle are stable. The grain size of NiAl phase is about 400nm and it is coherent with the ferrite matrix.
General formulas of coning compensation algorithm with angular rate input
Yang Sheng, Fang Jiancheng
2008, 34(8): 920-924.
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When the traditional coning compensation algorithm applied in the strapdown inertial navigation system (SINS), which comprises of angular rate gyroscopes, the algorithm error increased dramatically. The general formulas of coning compensation algorithm, taking arbitrary samples of angular rate signal as input, were presented. Together with an improved algorithm, which utilizes angular rate signal and gyro increments from previous and current attitude update periods simultaneously. Then the algorithms were optimized by minimizing algorithm drift error under classical coning motion, and the coning compensation coefficient equations and algorithm error expressions were deduced respectively. The coning compensation algorithms, with arbitrary samples of angular rate signal as input, can be easily obtained from the deduced formulas. And the corresponding coefficients can be computed from the linear equations. Simulation result shows that the improved angular rate coning compensation algorithm was greatly improved in accuracy than regular algorithm with the same number of gyro angular rate samples.
Computer network defense policy model
Xia Chunhe, Wei Yudi, Li Xiaojian, He Wei
2008, 34(8): 925-929.
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Recent research on computer network defense is lack of a method which is able to model policy in high level and refine policy conveniently, hence computer network defense policy model (CNDPM) was presented to abstract network defense control behavior on the basis of organization based access control model (Or-BAC). The CNDPM provides a common method to model protection, detection and response policy, and introduces automatic assignment mechanism of role as well as view and activity to improve efficiency, also provides derivation principles to refine policy to concrete defense rule. Moreover, completeness, validity and consistency of policy are studied through formal analysis. The example shows that computer network defense policies modeled by CNDPM can be refined to defense rules conveniently and efficiently. The CNDPM model is characterized by good expansibility and practicability.
Link scheduler for network-on-chip
Zhang Zhe, Long Xiang, Gao Xiaopeng
2008, 34(8): 930-934.
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Wormhole-switching is usually employed in the emerging network-on-chip (NoC), in which the link scheduler can hardly guarantee the packet-level latency. Reverse anchored round-robin (RARR) is proposed as hybrid of the flit-by-flit round-robin (FFRR) and the packet-by-packet round-robin (PPRR). In the scheme of RARR, before the head flits have arrived at the destination, the packets are forwarded flit by flit. Then the scheduler at the destination link starts attempting to mark all fragments of the packet as anchors, which is accomplished by requesting and scheduling following the path reversely and hop by hop. The anchored packet takes priority over others, and will be scheduled at packet level. Others will be scheduled flit by flit only if the anchored one breaks. The RARR is inspired by the anchored round-robin (ARR), but employs more determinate anchoring scheme and eliminates the deadlock in ARR. Familiar round-robin were quantified via a cycle-accurate wormhole network simulator, including FFRR, PPRR, ARR and RARR. The RARR was shown to be most efficient among them.
Least squares based recursive identification for stochastic systems with colored noises
Wang Dongqing
2008, 34(8): 935-939.
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An auxiliary model and least squares based recursive identification algorithm was presented for stochastic systems with colored noises. The basic idea is, by means of the auxiliary model identification principle and extended least squares identification theory, to replace the unknown variables in the information vector with the outputs of the auxiliary model and to replace the unmeasurable noise terms with the estimated residuals, and then to propose a recursive identification algorithm to estimate all parameters of the systems, including the parameters of the noise models. The simulation results indicate that the algorithm is effective.
Novel method of extraction for binary based on hardware
Lai Dayu, Liu Rongke
2008, 34(8): 940-943.
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A method of any order extraction, works from left to right, which is based on hardware and calculates out the most significant bit(MSB) of the result first and the least significant bit(LSB) last. While applied in field programmable gate array(FPGA), the method can combine with looking up table(LUT). Using this method, the occupying time is linear to the extraction order. While doing a 3 order extraction for a 12 bit data, the occupying time of this method is 50% less than the traditional searching method, and the occupying memory is only 2% that of traditional method of LUT. As the order of extraction grows, the superiority will be more obvious. More important, the module only need to be modified in 2 point, the precision can be improved as wanted.
Direct numerical simulations of turbulent channel flows with spanwise moving wall
Wan Xi, Ma Shuwei, Zhang Jinbai, Li Chunxuan
2008, 34(8): 944-947.
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The influence of spanwise moving wall on turbulent channel flows is investigated using direct numerical simulations(DNS), which in order to know the characteristics of turbulent channel flows when existing spanwise moving velocity. The DNS is performed using the standard spectral method. Three cases with the spanwise wall moving velocity which equals 0, bulk flow velocity and double bulk flow velocity are simulated at constant mass flow rate. The results show that spanwise moving wall induce the skin friction increasing. The second-order turbulence statistics such as root-mean-square velocity fluctuations, Reynolds shear stress and root-mean-square vorticity fluctuations are substantial increase with spanwise velocity increasing. It is also observed that the root-mean-square velocity fluctuations become more even across the channel with spanwise velocity increasing.
Model of satellite data transmission scheduling problem based on multi-satellite combined reconnaissance
Li Yunfeng, Wu Xiaoyue
2008, 34(8): 948-951.
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Satellite data transmission scheduling problem based on multi-satellite combined reconnaissance is such a problem that studies how to assign ground resources and data transmitting time for every single data transmission task belonged to satellite data transmission task.A study of the problem-s model was made. To this problem, the models of single data transmission task and satellite data transmission task were constructed firstly. Based on these models, the model of this problem was constructed, and the object function and main constraints were analyzed especially. For solving the problem, a heuristic scheduling algorithm named double complex priority algorithm (DCPA) was presented and validated by an example lastly. The studying results realize formalizing description of the problem, and give a valid solving algorithm for it.
Calculation model of infrared radiation of cruise missile and atmospheric attenuation
Mao Xia, Dong Xuyang, Diao Weihe
2008, 34(8): 952-955.
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Three primary radiant points of the cruise missile, i.e. fuselage, hot spot and plume were analyzed, and an infrared radiation calculation model of cruise missile was established. Secondly, synthetically considering various factors such as height, slope and weather conditions, the influence of atmospheric attenuation was analyzed based on the theory of atmospheric transmission of the infrared radiation, and an theoretic model and calculation method of the atmospheric transmittance were established. Finally, take a certain cruise missile for example, the infrared radiation in 3~5μm and 8~12μm were computed based on the computing model. The atmospheric spectral transmittance and average transmittance and the infrared radiation attenuated were also calculated. An analysis of the results was also given.The results indicate that this is a simple method to calculate the infrared radiation of the cruice missile.
Three descriptions of coning motion and its influence
Yu Yang, Zhang Hongyue
2008, 34(8): 956-960.
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Basing on rotation vector method, Euler angles method and finite rotations method, the coning motion and its influence were discussed. Then the expressions of equivalent gyro drift in each method and their relationship were obtained. At last compensate precision of two-intervals coning compensate algorithm was researched in each method. The results show that finite rotations method and rotation vector method are equivalent absolutely. Euler angles method and rotation vector method are equivalent only when oscillation angles are small. Coning compensate algorithms are effectual both in rotation vector method and Euler angles method, and besides, compensate precisions are equivalent when oscillation angles are small. Rotation vector method and finite rotations method can be used to design coning compensation algorithms and Euler angles method can be used to design the test of the coning motion.
Analogy performance of flow and heat transfer on the V groove surface
Liu Kun, Tao Zhi, Wu Hong, Wang Jiao
2008, 34(8): 961-963.
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The drag and heat transfer characteristics of small longitudinal V groove surfaces in the rectangular channel were investigated experimentally based on the Reynold analogy. Within the range of Reynolds number from 10 000 to 80 000, the experimental results indicated that the V groove surface of h=s=0.5mm had drag-reduction characteristics,and the heat transfer of the V groove surface also be weakened, which demonstrates the correctness of the theory of Reynold analogy. The weakeness of heat transfer and drag-reduction decreased as Reynolds number increased. The decrease of heat transfer and drag-reduction contributed to the improvement of performance of aircraft engine, which will be beneficial to the flow and heat transfer when this type of surface applys to the surface of turbine vane.
Kinematic analysis and simulation of saddle-back coping welding robot
Li Xiaohui, Wang Su
2008, 34(8): 964-968.
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Aiming at the special request of complicated intersection line robot welding, a kind of saddle-back coping welding robot was presented, which has five axes. The robot mechanistic structure was reduced essentially and rationally. The five-axis robot D-H (Denavit-Hartenberg) links- coordinates were established with the reduced robot mechanistic structure. Then the forward solution and the inverse kinematics equations were built according to D-H links- coordinates. The singular solution of inverse kinematics equations was educed associated with the kinematic parameters change range. Programming in the Matlab software according to the forward solution and inverse kinematics equations, the five-axis robot kinematic analysis was simulated. The simulative calculations results indicate that forward solution and inverse kinematics equations are completely accurate. And the simulation accuracy shows that the solution of inverse kinematics equations satisfies the welding project well. It is very important to welding robot and can provide a theoretical basis and supports algorithm for trajectory regulation and off-line programming.
Online mining frequent closed itemsets over data stream
Liu Chun, Zheng Zheng, Cai Kaiyuan, Zhang Shichao
2008, 34(8): 969-972.
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Based on the algorithm LossCounting, a novel approach called LossyCounting_Closed(LC_Closed ) for mining closed frequent itemsets over data stream was proposed. A new summary data structure called Closed-Itemsets-forest (CI-forest) was developed for maintaining only closed frequent itemsets.The insertion and query of closed itemsets can be rapidly made based on the data structure CI-forest, and the location of the associated historical closed itemsets in the stage of dealing with the new transaction is also facilitated by CI-forest. Since the algorithm maintains closed itemsets online, the current closed frequent itemsets can be output in real time based on user-s specified thresholds. The effectiveness of the proposed method is shown in the experimental results.
Research on failure rate model of lithium-ion batteries
Jia Ying, Li Huolin
2008, 34(8): 973-975.
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Base failure rate model and operating failure rate model were developed to predict the reliability of the lithium-ion batteries. Firstly, the mostly failure models of lithium-ion batteries were analysised, and the operating current and temperature were regarded as the main accelerating factors of the failure of lithium-ion batteries. Secondly, consulting the GJB/Z299 , the life-testing data was used to calculating the numerical values of the parameters of the models, and to buid the adjusting coefficient(π-coefficient)project. By using the models, the predicting failure values under different operating currents and temperatures were calculated. The predicting failure values were then compared with the life-testing values. The results indicate that the base failure rate model and operating failure rate model are feasible for engineering practise.
SVM based float car driving mode classification model
Zhu Tongyu, Guo Shengmin, Lü Weifeng
2008, 34(8): 976-980.
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There are two kinds of driving modes of float car at low speed. The misjudgement of these modes will affect the accuracy and efficiency of the calculation of float car real-time traffic conditions seriously. A SVM(support vector machine) based float car driving mode classification model was studied and designed, and a novel membership matrix-based feature evaluation and selection method was proposed. The classifier whose features are selected through this method made a great classification accuracy of 92.6% in test samples. The float car driving mode analysis enhances the accuracy of exiting system evidently.
Random vibration response analysis of hypersonic flight vehicle ramjet combustor chamber structure
Gao Jinhai, Ma Yanhong, Hong Jie, Liu Wei
2008, 34(8): 981-985.
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The testing results of combustion chamber structure of hypersonic ramjet were used, which finished the analysis to structure random vibration response of combustion chamber shell. Meanwhile, both of them were compared ,which gave us a satisfied consequence. The analysis and technology method of random vibration response of vehicle complex structure were verified by this test. On the basis of that by taking advantage of pressure load data and analysising the random vibration response of combustor chamber in flight regime, the RMS(Root Mean Square) and PSD(Power Spectral Density) of acceleration response were presented, which was very important to the work of preliminary of dynamic environment of fight vehicle.
Numerical simulation of intersection line welding in installation pedestal on aeroengine combustion chamber
Wang Su, Zhou Feng, Zhang Yingli
2008, 34(8): 986-990.
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A numerical analysis modeling was created about the installation pedestal on aeroengine combustion chamber, which is one of the crucial parts of the aeroengine during the process of intersection line welding. Deformation caused by the intersection line welding at the joint between the two cylindrical shells was studied using the finite element analysis method based on SYSWELD. Temperature field, welded joint stress field, phase transition and deformation in intersection line welding on installation pedestal were simulated. Linked with the factual conditions of the installation pedestal, the simulation result was discussed and the deformation in intersection line welding was analyzed using mathematic method. The deformation distribution and location of the modeling were defined. These will provide a theoretic reference for factual installation pedestal welding, and are useful to optimize the technology of the installation pedestal welding. This method also provides a reference to solve similar problems in welding fields.

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