Fatigue Life Evaluation in Frequency Domain of aircraft Equipment Exposed to Random Vibration

무작위 진동에 노출된 항공기 탑재 장비의 주파수영역 피로수명 평가

  • Jung, Hyun Su (Mechanical R&D Laboratory, LIG Nex1 Co., Ltd.) ;
  • Kim, Ki Seung (Mechanical R&D Laboratory, LIG Nex1 Co., Ltd.) ;
  • Kim, Jun Su (Mechanical R&D Laboratory, LIG Nex1 Co., Ltd.) ;
  • Lee, Seong Woo (The 3 rd Research and Development Institute, Agency for Defense Development)
  • Received : 2017.02.22
  • Accepted : 2017.06.30
  • Published : 2017.08.01


Expecting fatigue life of mounted radar in aircraft is very important when designing, because the mounted radar in aircraft is exposed to long-term external random vibration. Among the methods of predicting the fatigue life, Fatigue analysis method in frequency domain has continuously been proposed in this field. In this paper, four fatigue analysis methods in frequency domain, which are widely used, have been selected and compared with the results for Specimen fatigue test. As a result, Dirlik and Benascicutti-Tovo methods have been matched better with fatigue analysis in time domain than the method in frequency method through the comparison between the fatigue analysis method in time domain and the method in frequency domain by conducting the specimen fatigue test with strain gage. Based on the results of the specimen fatigue test, We have conducted fatigue analysis of mounted radar in aircraft with Dirlik and Benasciutti-Tovo methods in the finite element model, and confirmed that the required life was satisfying.


  1. palmgren A., "Die lebensdauer von kugellagern," VDI-Zeitschrift, vol. 68, 1924, pp.339-341
  2. Miner M. A., "Cumulative damage in fatigue," Journal of applied mechanic, vol. 67, 1945, pp.159-164.
  3. Aykan M., Celik M., "Vibration fatigue analysis and multi-axial effect in testing of aerospace structures," Mechanical systems signal process, vol. 23, 2009, pp.897-907
  4. Fang Liu, Ye Lu, Zhen Wang, Zhiming zhahg, "Numerical simulation and fatigue life estimation of BGA packages under random vibration loading," Microelectronics Reliability, vol. 55, 2015, pp.2777-2785.
  5. Yu Du, Lu Shi, " Effect of vibration fatigue on modal properties of single lap adhesive joints," International Journal of Adhesion and Adhesives, vol. 53, 2014, pp.72-79
  6. Seung-Ho Han, Dae-Gyun An, Seong-Jong Kwak, Ki-Weon Kang, "Vibration fatigue analysis for multi-point spot-welded joints based on frequency response changes due to fatigue damage accumulation," International Journal fo Fatigue, vol. 48, 2013, pp.170-177.
  7. Geun won Kim and Ki su Shin, "The effect on fatigue life for dynamic behavior of external fuel horizontal fin," Lorea society for aeronautical & space sciences, vol.40, 2012, pp.209-214.
  8. M. Matsuishi, T. Endo, "Fatigue of metals subjected to varying stress," Japan society of mechanical engineers, 1968.
  9. Wirsching P.H. & Light M.C., "Fatigue under wide band random stresses," Journal of the structural Division, Proceeding of the ASCE, 106(ST7), 1980, pp.1593-1607.
  10. Miles J.W., "On structual fatigue under random loading," Journal of the aeronautical sciences, vol. 21, 1965, pp.753-762.
  11. Dirlik T., "Application of computers in fatigue analysis," Ph.D. thesis. The University of WarWick, 1985.
  12. D. S. Steinberg, "Vibration Analysis for Electronic Equipment," John Wiley & Sons, 3rd edition, USA, 2000.
  13. Rychlik I., "On the narrow-band approximation for expected fatigue damage," Probabilistic engineering mechanics, vol. 8(1), 1993, pp.1-4.
  14. Benasciutti D. & Tovo R., "Spectral methods for lifetime prediction under wide-band stationary random processes," International journal of fatigue, vol. 27(8), 2005, pp.867-877.
  15. M. F. E. Ibrahim, K. J. Miller "Determination of fatigue crack initiation life," Fatigue & Fracture of engineering material & structure, vol. 2, 1979, pp.351-360
  16. William J., Baxter, Pei-Chung Wang, "Finite element prediction of high cycle fatigue life of aluminum alloys," Metallurgical and materials Transactions A, vol. 21, 1990, pp.1151-1159.
  17. Q. Y. Wang, C. Bathias, N. Kawagoishi, Q. Chen, "Effect of inclusion on subsurface crack initiation and gigacycle fatigue strength," international Journal of fatigue, 24, 2002, pp.1269-1274.
  18. Jeong Kim, Joo-Cheol Yoon, Beom-Soo Kang, "Finite element analysis and modeling of structure with bolted joints," Applied Mathemtical Modeling, 31, 2007, pp.895-911.
  19. MIL-STD-810G, Environmental Engineering Considerations and Laboratory Tests, Department of Defense Test Method Standard, USA, 2000.
  20. MIL-HDBK-5J, Metallic materials and elements for aerospace vehicle structures, Department of Defense handbook, USA, 2003.