Journal of Aerospace System Engineering (항공우주시스템공학회지)

The Society for Aerospace System Engineering (항공우주시스템공학회)
권호 표지
DOI QR코드

DOI QR Code

Fatigue Life Prediction of Sensor Pod for Aircraft Considering Aircraft Loads

비행체 하중을 고려한 항공기용 센서 포드의 피로수명 예측

  • Cho, Jae Myung (Department of Mechanical Engineering, Graduate School, Korea university) ;
  • Jang, Joon (Department of Mechanical Engineering, Graduate School, Korea university) ;
  • Choi, Woo Chun (School of Mechanical Engineering, Korea university) ;
  • Bae, Jong In (Hanwha Systems)
  • 조재명 (고려대학교 대학원 기계공학과) ;
  • 장준 (고려대학교 대학원 기계공학과) ;
  • 최우천 (고려대학교 기계공학부) ;
  • 배종인 (한화시스템)
  • Received : 2019.02.01
  • Accepted : 2019.06.10
  • Published : 2019.06.30
Download PDF
⟨ Previous Next ⟩

Abstract

Sensor pods mounted on the exterior of the aircraft used for tactical missions should have a fatigue life based on the expected load spectrum during operation. For mission equipment such as the sensor pod, the frequency fatigue life prediction method which applies the dynamic vibration environment condition is preferred due to the efficiency of the analysis. In this paper, a fatigue life prediction method in the frequency domain where stress due to static and dynamic loads is synthesized based on the actual flight load spectrum is proposed. After comparison with the existing analysis method, the fatigue life of the proposed analysis method was predicted conservatively. The proposed sensor pods satisfy the requirements of the fatigue life.

항공기 외부에 장착되어 전술임무에 사용되는 센서 포드는 운용기간 동안 예상되는 하중 스펙트럼에 대한 피로수명이 확보되어야 한다. 센서 포드와 같은 임무장비는 해석의 효율성을 고려하여 동적 진동 환경조건을 적용한 주파수 영역의 피로수명 예측방법이 선호되어 왔다. 본 논문에서는 실제 비행체 하중 스펙트럼을 고려하여 정적 및 동적 하중에 의한 응력을 합성한 주파수 영역에서의 피로수명 예측방법을 제안하였다. 기존 해석방법과 비교한 결과 제안된 해석방법은 피로수명이 보수적으로 예측되었다. 그리고 제안된 방법으로 해석한 결과 설계된 센서 포드는 피로수명 요구조건을 만족하였다.

Keywords

OJSSBW_2019_v13n3_32_f0001.png 이미지

Fig. 1 Sensor Pod

OJSSBW_2019_v13n3_32_f0002.png 이미지

Fig. 2 Fatigue Prediction Process

OJSSBW_2019_v13n3_32_f0003.png 이미지

Fig. 3 Finite Element Model of Sensor Pod

OJSSBW_2019_v13n3_32_f0004.png 이미지

Fig. 4 Static Analysis of the Sensor Pod

OJSSBW_2019_v13n3_32_f0005.png 이미지

Fig. 5 Jet Aircraft Vibration Exposure

OJSSBW_2019_v13n3_32_f0006.png 이미지

Fig. 6 Frequency Response Analysis

OJSSBW_2019_v13n3_32_f0007.png 이미지

Fig. 7 Dirlik Method vs Steinberg Method

OJSSBW_2019_v13n3_32_f0008.png 이미지

Fig. 8 Fatigue Life Comparison(Steinberg Method)

OJSSBW_2019_v13n3_32_f0009.png 이미지

Fig. 9 Fatigue Stress Comparison of Adapter Structure

Table 1 Aircraft Loads

OJSSBW_2019_v13n3_32_t0001.png 이미지

Table 2 Material Properties

OJSSBW_2019_v13n3_32_t0002.png 이미지

References

  1. Fedral Aviation Regulation Part 25, Airworthiness Standards, Transport Category Airplanes, FAA, 1968.
  2. MIL-STD-1530A, Aircraft Structural Integrity Program, Airplane Requirments, 11 Dec. 1975.
  3. MIL-STD-810G, Environmental Engineering Considerations and Laboratory Tests, Department of Defense Test Method Standard, 31 Oct. 2008.
  4. NATO AECTP 400, Mechanical Environmental Tests, NATO AECTP 400, Ed 3, Jan. 2006
  5. M. Matsuishi and T. Endo, "Fatigue of metals subjected to varying stress," Japan society of mechanical engineers, 1968.
  6. A. Palmgren, "Durability of Ball Bearings," VDIZeitschrift, vol. 68, no. 14, pp. 339-341, 1924
  7. M. A. Miner, "Cumulative Damage in Fatigue," Journal of Applied Mechaic, vol. 12, pp. A159-A164, 1945 https://doi.org/10.1115/1.4009458
  8. H. Andrew and K. Frederic, "Rainflow cycle counting and acoustic fatigue analysis techniques for random loading," 10 International Conference RASD, Southampton, July 2010.
  9. M. Mrsnik, J. Slavic and M. Boltezar, "Frequency-domain methods for a vibration-fatigue-life estimation - Application to real data," International Journal of Fatigue, vol. 47, pp. 8-17, 2013. https://doi.org/10.1016/j.ijfatigue.2012.07.005
  10. H. S. Jung, K. S. Kim, J. S. Kim and S. W. Lee, "Fatigue Life Evaluation in Frequency Domain of aircraft Equipment Exposed to Random Vibration," Journal of The Korean Society for Aeronautical and Space Sciences, vol. 45, no. 8, pp. 627-628, 2017 https://doi.org/10.5139/JKSAS.2017.45.8.627
  11. A. Halfpenny, "Accelerated Vibration Testing Based on Fatiue Damage Spectra," nCode International, 230 Woodbourn Road, Sheffield S9 3LQ, UK
  12. NRTO, Aging Aircraft Fleets: Structural and Other Subsystem Aspects, 2000
  13. S. O. Rice, "Mathematical Analysis of Random Noise," Selected Papers on Noise and Stochastic Processes, Dover, New York, 1954.
  14. D. E. Newland, An Introduction to Random Vibrations, Spectral & Wavelet Analysis. Longman Scientific & Technical, 1993.
  15. K. Shin and J. K. Hammond, Fundamentals of signal processing for sound and vibration engineers. John Willey & Sons, Ltd, 2008.
  16. John W. Miles, "On Structural Fatigue Under Random Loading", Journal of the Aeronautical Sciences, vol. 21, no. 11, pp. 753-762, 1954 https://doi.org/10.2514/8.3199
  17. D. S. Steinberg, "Vibration Analysis for Electronic Equipment," John Wiley & Sons, 3rd edition, USA, 2000.
  18. T. Dirlik, "Application of computers in Fatigue Analysis", Ph.D. Thesis, University of Warwick, 1985.
  19. J. Goodman, Mechanics applied to engineering, Longman, Green & Co, 1954.
  20. MIL-HDBK-5J, Metallic materials and elements for aerospace vehicle structures, Department of Defense handbook, USA, 2003.