항공기 착륙장치 내 브래킷 균열 원인 및 개선에 관한 연구
A Study on Bracket Crack Causes and Improvements in Landing Gear
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초록
This study analyzed the defects occurring in the bracket, which is a component of the landing gear, caused by vibrations made from the ground during the landing process of an aircraft. Accordingly, for the problem of bending or pressing and cracks occurring in the bracket, the shape and location were checked using a fluorescent penetrant inspection, and the cause of the crack was identified using Finite Elements Method(FEM). Through this, it was confirmed that the cause of the crack generated in the bracket was due to repetitive contraction and relaxation of the hydraulic hose connected to the landing device. Therefore, to prevent cracking, a washer was installed on the up-lock roller bearing bolt and a corner radius was added to the bracket to distribute the concentrated load. After that, in order to confirm the structural stability of the improved shape, the structural stability of the improved shape was confirmed by comparing the stress generated in the crack area with the existing shape through finite element analysis. In addition, in order to check the lifetime of the improved shape, the lifetime of more than 54,000 hours was confirmed by using Miner’s Rule and the S-N diagram for the bracket material AL2024-T3. Also, by calculating a static strength margin value of +0.05, it was confirmed that the improved shape satisfies the structural safety.
Abstract
This study analyzed the defects occurring in the bracket, which is a component of the landing gear, caused by vibrations made from the ground during the landing process of an aircraft. Accordingly, for the problem of bending or pressing and cracks occurring in the bracket, the shape and location were checked using a fluorescent penetrant inspection, and the cause of the crack was identified using Finite Elements Method(FEM). Through this, it was confirmed that the cause of the crack generated in the bracket was due to repetitive contraction and relaxation of the hydraulic hose connected to the landing device. Therefore, to prevent cracking, a washer was installed on the up-lock roller bearing bolt and a corner radius was added to the bracket to distribute the concentrated load. After that, in order to confirm the structural stability of the improved shape, the structural stability of the improved shape was confirmed by comparing the stress generated in the crack area with the existing shape through finite element analysis. In addition, in order to check the lifetime of the improved shape, the lifetime of more than 54,000 hours was confirmed by using Miner’s Rule and the S-N diagram for the bracket material AL2024-T3. Also, by calculating a static strength margin value of +0.05, it was confirmed that the improved shape satisfies the structural safety.
참고문헌 (9)
- Lee, S., "Performance Analysis of Main Landing Gear for KT-1 Family Aircraft", Proceeding of KSAS Spring Conference, 40(4), pp.211~214 (2006)
- 이정선, "착륙장치 작동기 내부 잠금장치 피로해석", 대한기계학회논문집 A, 36(1), pp.91~96 (2012), 대한기계학회
- Kim, K., "Stress Analysis of Plate-Spring-Type Landing Gear Materials", Proceeding of KSME Spring Symposium, 38(3), pp.303~308 (2014)
- "KDS 1620-1015, Landing gear, NOSE, AIRCRAFT, KANL-1", Defense Acquisition Program Administration, ~ (2020)
- "KDS 1620-1016, LANDING GEAR, MAIN, AIRCRAFT, KANL-1", Defense Acquisition Program Administration, ~ (1998)
- 허장욱, "항공기 엔진 지지구조물의 피로수명 해석에 관한 연구", 대한기계학회논문집 A, 34(11), pp.1667~1674 (2010), 대한기계학회
- "MIL-HBDK-5J, METALLIC MATERIALS AND ELEMENTS FOR AEROSPACE VEHICLE STRUCTURES", ~ (2003)
- Chang, D., "Verification of Applicability of Engineering Fatigue Analysis Method Using Detailed Finite Element Analyses", Proceeding of KSME Spring Symposium, pp.325~326 (2019)
- Kim, K., "The Fatigue Analysis Using Cummulative Damage Rule(Miner’s Rule)for The Welding Areas of Carbody Structure", Journal of The Korean Society for Railway, pp.29~33 (2017)