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Jiang Y.-F.,Beijing Aircraft Strength Institute | Pan X.,Beihang University | Zhang S.-M.,Beijing Aircraft Strength Institute | Yan C.-L.,Beihang University
Zhongguo Guanxing Jishu Xuebao/Journal of Chinese Inertial Technology | Year: 2015

Under the condition of dynamical vibration in determinate application environments, it is an inevitable requirement of engineering for FOG to retain its output precision, and choosing suitable materials for the structure of FOG is one of the key technologies. Based on the theory of FOG's structural vibration performance, beryllium aluminum alloy is introduced in the key structure of the small and light FOG, and the FOG's finite element model is used to implement the simulation. Simulation results show that the FOG's resonance is greater than 2 kHz. An experimental FOG prototype (accuracy 0.1°/h) with beryllium aluminum alloy structure is used in sine sweep vibration experiments (frequency from 10 Hz to 2 kHz). There are no resonances, and the FOG's zero bias variation is 0.04 (°)/h. The noise level remains almost the same. The results show that the excellent properties of beryllium aluminum alloy meet the vibration performance requirements of light and small FOG, and can decrease the difficulty of structural design under strict weight constraints, especially satisfying the demanding requirements of the inertial instrument's quality in the field of aerospace. © 2015, Editorial Department of Journal of Chinese Inertial Technology. All right reserved.

Tian Z.,Beijing Aircraft Strength Institute | Yan C.,Beijing Aircraft Strength Institute
Beijing Hangkong Hangtian Daxue Xuebao/Journal of Beijing University of Aeronautics and Astronautics | Year: 2015

Aircraft load spectrum measured data visual simulation is an important means to identify maneuver and to verify the validity of measured data in flight testing. A data storage method based on logical data channels was put forward to solve the structural differentiation problem of different data sources caused by different measured objects; for the performance problems caused by model complexity when large amount of measured data was used to simulate the whole flight course, physical channel and logical data channel analytical model were established; based on data double-buffering and drawing double-buffering mechanisms, flight model and visual simulation system environment of measured data were established, and the measured flight data of different testing aircrafts were analyzed and verified. The results show that the visual system meets the verification of flight measured data and the demand of maneuver recognition of GB level load spectrum of different types well, and can reproduce the entire course of the flight completely. It provides a visual platform to identify maneuver of flight course of aircraft, verify the data validity and post process of data. ©, 2015, Beijing University of Aeronautics and Astronautics (BUAA). All right reserved.

Han X.,Beijing Aircraft Strength Institute | Sun H.,Nanjing University of Aeronautics and Astronautics | Yan G.,Jilin University | Yan C.,Beijing Aircraft Strength Institute
Fuhe Cailiao Xuebao/Acta Materiae Compositae Sinica | Year: 2012

Based on the continuum damage theory, the stress-strain relationship for orthotropic materials with damage cracks was derived. A representative volume unit cell for 3D five-directional braided composites was constructed, in which the debonding on the interface was considered. The sizes of the finite element mesh and the crack were considered in the damage evolution equation. The Hashin and von-Mises criteria were used for prediction of the initial damage of yarns and matrix, and the Eshelby-Mori-Tanaka method was applied to calculate the stiffness reduction factor. The progressive damage behaviors were simulated by ANSYS, and the stress-strain curve and the critical strength under uniaxial tensile loading were obtained. It is shown that the main failure mode of the composites with a low braiding angle is yarn cracking with serious damage on the interface. The results from the simulation agree well with the experiments in the existing literature.

Tian Z.,Beijing Aircraft Strength Institute | Yan C.,Beijing Aircraft Strength Institute
Zhendong Ceshi Yu Zhenduan/Journal of Vibration, Measurement and Diagnosis | Year: 2011

To realize experimental data visualization of aircraft flight course based on web application, modeling method of three-dimensions objects and flight data driven method are studied by using open graphics library and web development technology. Multi-view data visualization of flight course reappears from flight-tests data. And according to the system, whether the flight-test data met flight-test outline is able to be determined. The data visualization system provides an intuitive way to prove the validity of flight-test data. The system could be applied to any type of aircrafts as long as data description file and model configuration file are configured correctly.

Hao Y.-X.,Beijing Aircraft Strength Institute
Hedianzixue Yu Tance Jishu/Nuclear Electronics and Detection Technology | Year: 2012

CdZnTe nuclear radiation detector is conveniently utilized as X, γ-ray detectors for its high detecting efficiency and good energy resolution, and it has become a preference for many applications in the field of environmental monitoring, industrial non-destructive testing, and so on. The CdZnTe detector has kinds of structures, but quasi-hemispherical is studied little in China. A quasi-hemispherical CdZnTe detector (8 mm×8 mm×4 mm) was fabricated. The leakage current of the detector is in nA; the energy resolutions (FWHM) are respectively 6.96%, 5.66%, 3.92% when it was evaluated using un-collimated 241Am (59.5 keV), 57Co (122 keV), 137Cs (662 keV) radioactive sources at room temperature; and the performance is stable in the 8 hours of continuous work situation.

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