• Title/Summary/Keyword: Instrumented Pod

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Study of Analysis Technique of Flight Compatibility Test Data using Instrumented Pod for External Store (외부장착 계측포드를 사용한 비행적합성 자료 분석기법 연구)

  • Kim, Jong-Heon;Jun, Oo-Chul;Jun, Seung-Moon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.33 no.8
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    • pp.105-110
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    • 2005
  • Analysis technique of flight compatibility test results using instrumented pod for external store is studied. Raw data of sensors and MIL-STD-1553B acquired from instrumented pod are analyzed separately. Besides, tuning and synchronization of sensor data enable the analysis of those two type of data simultaneously. Evaluation of analysis result shows that the analyzed data represent maneuvers of the aircraft successfully and agree the values of the real flight tests.

Design of Instrumented Pod for Flight Aeroacoustic Environment (비행 공력음향 환경 측정을 위한 계측포드 설계)

  • Jun, Oo-Chul;Kim, Sang-Yong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.40 no.6
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    • pp.536-541
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    • 2012
  • An instrumented pod has been developed to measure the aeroacoustic environment as well as the conventional data such as load, vibration, and aerodynamic heating of fighters during flight tests, confirming to the recently developed external pod design for fighters. This study presents the development of the measurement system in detail, being the first indigenous effort in its kind. The pod was designed to meet the requirements of the MIL-HDBK-1763 and MIL-STD-810 Method 515, which are the base to determine the locations and range of sensors. The Endevco 8510B-2 was selected as the sensor to withstand the harsh environment during the flight tests. In order to assess the integrity of the fabricated pod design, a ground run-up test of a KF-16 has been conducted with the pod installed at Station 5. The test results show that the system works well but the sound level exceeds the predetermined sensor range. The sensor range has been readjusted for flight test performed later.

Modal identifiability of a cable-stayed bridge using proper orthogonal decomposition

  • Li, M.;Ni, Y.Q.
    • Smart Structures and Systems
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    • v.17 no.3
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    • pp.413-429
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    • 2016
  • The recent research on proper orthogonal decomposition (POD) has revealed the linkage between proper orthogonal modes and linear normal modes. This paper presents an investigation into the modal identifiability of an instrumented cable-stayed bridge using an adapted POD technique with a band-pass filtering scheme. The band-pass POD method is applied to the datasets available for this benchmark study, aiming to identify the vibration modes of the bridge and find out the so-called deficient modes which are unidentifiable under normal excitation conditions. It turns out that the second mode of the bridge cannot be stably identified under weak wind conditions and is therefore regarded as a deficient mode. To judge if the deficient mode is due to its low contribution to the structural response under weak wind conditions, modal coordinates are derived for different modes by the band-pass POD technique and an energy participation factor is defined to evaluate the energy participation of each vibration mode under different wind excitation conditions. From the non-blind datasets, it is found that the vibration modes can be reliably identified only when the energy participation factor exceeds a certain threshold value. With the identified threshold value, modal identifiability in use of the blind datasets from the same structure is examined.