Bonded Repair of Aircraft Structures

1. Introductory chapter.- 1.1 Bonded vs bolted repairs.- 1.2 Combined bonded/bolted repairs.- 1.3 Adhesives.- 1.4 Adhesive testing.- 1.5 Surface preparation.- 1.6 Environmental behaviour.- 1.7 Summary.- 2. Surface treatments for bonded repairs of metallic components.- 2.1 Introduction.- 2.2 Background.- 2.3 Structural aluminium alloys.- 2.4 Phosphoric acid anodizing.- 2.5 Chromic acid anodizing.- 2.6 Titanium alloys.- 2.7 Summary.- 3. Design and analysis of bonded repairs for metal aircraft structures.- 3.1 Introduction.- 3.2 Design of adhesive bonded repairs in thin sheet metal construction.- 3.3 Residual strength of flawed or damaged bonded joints.- 3.4 Acceptance criteria for bonded flaws and damage.- 3.5 The pitfalls of life prediction for adhesive-bonded joints.- 3.6 Surface preparation for adhesive bonded repair of metal structure.- 3.7 Conclusions.- 4. Crack patching: design aspects.- 4.1 Introduction.- 4.2 The finite element formulation.- 4.3 Repair of cracks in Mirage III lower wing skin - a design study.- 4.4 Neutral axis offset effects.- 4.5 Initial design procedures.- 4.6 Comparison with experimental and 3-D results.- 4.7 Repair of semi elliptical surface flaws.- 4.8 Repair of cracked holes.- 4.9 Repair of cracked fastener holes.- Appendix A.- 5. Theoretical analysis of crack patching.- 5.1 Introduction.- 5.2 Formulation and notation.- 5.3 Load transfer to bonded reinforcements.- 5.4 Two stage analytical solution.- 5.5 Residual thermal stress due to adhesive curing.- 5.6 Bending effects.- 5.7 Partial reinforcement.- 5.8 Conclusion.- 6. Crack patching: experimental studies, practical applications.- 6.1 Introduction.- 6.2 Adhesive system and process selection.- 6.3 Thermal and residual stress problems.- 6.4 Design correlations and materials allowables.- 6.5 A preliminary design approach.- 6.6 Crack propagation behaviour.- 6.7 Applications of crack patching.- 7. Repair of composite aircraft.- 7.1 Introduction.- 7.2 Composite fabrication.- 7.3 Defects.- 7.4 Repair materials.- 7.5 Bonded repair - composite repair concepts.- 7.6 Effect of moisture on bonded repairs of composites.- 7.7 Design of bonded repairs.- 7.8 Composite service damage experience.- 7.9 Specific component repair.- 7.10 Future requirements.