Fatigue Crack Growth Failure and Lifing Analyses for Metallic Aircraft Structures and Components

1 Historical Review.- 1.1 FCG Parameters, Concepts and Testing.- 1.2 FCG 'Laws' and Models.- 1.3 Summary.- 2 Basic Information for Aircraft FCG Failure and Lifing Analyses.- 2.1 Importance of Fatigue for Aircraft Structural Failures.- 2.2 Fatigue Crack Nucleation, Discontinuities, Early FCG and Damage Tolerance.- 2.3 Summary of FCG Lifing Methods.- 3 Quantitative Fractography (QF) for FCG analyses.- 3.1 Introduction.- 3.2 Fatigue Striation FCG Analyses.- 3.3 Progression Marking FCG Analyses.- 3.4 Fatigue-nucleating Discontinuities and Equivalent Pre-crack Sizes (EPS).- 3.5 QF Techniques for Fatigue Fracture Surfaces.- 3.6 A Cautionary Note.- 4 Aermacchi MB-326H Wing Spar (1990): Exponential FCG Analysis.- 4.1 Introduction.- 4.2 FCG Analysis for the Failed Spar.- 4.3 Further Examination of Wing Spars.- 4.4 Lessons Learned.- 5 P&W 125B Engine Bearing (1994): 2-Stage Exponential FCG Analysis.- 5.1 Introduction.- 5.2 The Failed No.3 Bearing: Macroscopic and |Metallographic Examination.- 5.3 Cage Failure and FCG Analysis.- 5.4 Interpretation of the Results, Conclusions, and Remedial Action.- 6. EBA Example Lifing Assessment (2004): F/A-18 Horizontal StabilatorSpindles.- 6.1 Introduction.- 6.2 EBA Validation for the F/A-18 Horizontal Stabilator Spindles.- 6.3 EBA and Total Life Assessment for the F/A-18 Horizontal Stabilator Spindles.- 7. LCFLF Example Lifing Assessment (2004): F/A-18 Vertical Tail Attachment Stubs.- 7.1 Introduction.- 7.2 The FT46 Stub Flange Crack.- 7.3 Fractography of the FT46 Stub Flange Crack.- 7.4 LCFLF Life Assessment for the FT46 Stub Flange Crack.- 8. Cubic Rule Life Prediction Examples.- 8.1 Introduction.- 8.2 McDonnell Douglas F4E Spectrum Coupon Test Data.- 8.3 Lockheed Martin P3C Spectrum Coupon Test Data.- 8.4 Summary.- 9. Fokker 100 Fuselage Test: Lap Joints Exponential FCG Analysis.- 9.1 Introduction.- 9.2 FCG Analysis of the Cracked Lap Splice [71.72.95].- 10. Sikorsky S-61N Rotor Blade (1974): Exponential FCGR Analysis.- 10.1 Introduction.- 10.2 FCG Analysis for the Crashed Helicopter.- 10.3 Prediction of Detectable FCG Lives.- 10.4 Results and Remedial Actions (Lessons Learned).- 11. Westland Lynx Rotor Hub (1998): Progression Marking LEFM Analysis.- 11.1 Introduction.- 11.2 Fractography of Early Fatigue Cracking in the M326 Yellow Arm.- 11.3 Fractography of Early Fatigue Cracking in the M6 Arm and M326Specimens.- 11.4 FRTB + LEFM Estimations of Damaging Service Fatigue Stress Levels.- 11.5 Measurements of Service Loads and Fatigue Analysis by GKNW.- 11.6 Causes of Failure and Remedial Action.- 12. Closing Remarks.- References.