표제지
목차
Abstract 8
I. 서론 9
1.1. 연구배경 및 목적 9
1.2. 연구방법 11
II. 이론적 배경 13
2.1. 선형손상누적 법칙(Miner's rule) 13
2.2. 응력집중계수 계산 개념 14
III. 전륜 착륙장치 피로해석 15
3.1. 피로해석 취약부(Control point) 선정 15
3.2. 운용하중 스펙트럼 생성 19
3.3. 응력방정식(Stress equation) 생성 22
3.4. 피로손상(Fatigue damage) 해석 결과 23
IV. 전륜 착륙장치 피로시험 26
4.1. 시험체 구성 26
4.2. 시험하중 및 절차 27
4.3. 주요 피로시험 결과 29
4.3.1. 시험전 정적 변형률 측정 결과 29
4.3.2. 피로시험 중 변형률 측정 결과 30
V. 결론 33
참고 문헌 40
Table 1. NLG left keel beam CP fatigue analysis results 24
Table 2. NLG right keel beam CP fatigue analysis results 24
Table 3. NLG drag brace fitting CP fatigue analysis results 25
Fig. 1. Nose land gear support structure 15
Fig. 2. NLG left keel beam control point location 16
Fig. 3. NLG right keel beam control point location 17
Fig. 4. NLG drag brace fitting control point location 18
Fig. 5. Example of mission profile 19
Fig. 6. Example of mission events 20
Fig. 7. Design service loads spectra 21
Fig. 8. NLG keel beam S-N data 23
Fig. 9. NLGSS fatigue test article 26
Fig. 10. Dummy NLG & hydraulic actuator arrangement 28
Fig. 11. NLGSS fatigue test article and fixture 28
Fig. 12. Comparison result of static strain survey 29
Fig. 13. NLG left keel beam dynamic strain(CP #3) monitoring result of… 30
Fig. 14. NLG right keel beam dynamic strain(CP #1) monitoring result of… 31
Fig. 15. NLG drag brace fitting dynamic strain(CP #4) monitoring result of… 32
Fig. 16. Comparison result of static strain survey for spin-up 34
Fig. 17. Comparison result of static strain survey for HCE-max 35
Fig. 18. Comparison result of static strain survey for HCE-min 36
Fig. 20. Load spectrum configuration(Fz, left, ground & landing) 37
Fig. 20. Load spectrum configuration(Fz, right, ground & landing) 37
Fig. 21. Load spectrum configuration(retract & extend) 38
Fig. 22. Load spectrum configuration(Fz, retract & extend) 38
Fig. 23. Load spectrum configuration(Fz, up-lock) 39