Bonded Comp Repair of Metallic Aircraft Structure VOLUME 2 A .7 Alan Baker Francis Rose Rhys Jones Edited by ECSEVIER ADVANCES IN THE BONDED COMPOSITE REPAIR OF METALLIC AIRCRAFT STRUCTURE Volume 2 Elsevier Science Internet Homepage - http://www.elsevier.com Consult the Elsevier homepage for full catalogue information on all books, journals and electronic products and services. Elsevier Titles of Related Interest VALERY V. VASILEV & EVGENY V. MOROZOV Mechanics and Analysis of Composite Materials ISBN: 0 08 042702 2 JANG-KYO KIM & YIU WING MA1 Engineered Interfaces in Fiber Reinforced Composites ISBN: 0 08 042695 6 J.G. WILLIAMS &A. PAVAN Fracture of Polymers, Composites and Adhesives ISBN: 0 08 043710 9 D.R. MOORE, A. PAVAN & J.G. 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Should you have a publishing proposal you wish to discuss, please contact, without obligation, the publisher responsible for Elsevier's Composites and Ceramics programme: Emma Hurst Assistant Publishing Editor Elsevier Science Ltd The Boulevard, Langford Lane Phone: +44 1865843629 Kidlington, Oxford Fax: +44 1865 843931 OX5 IGB, UK E.mail: e.hurst@elsevier.com General enquiries, including placing orders, should be directed to Elsevier's Regional Sales Offices -please access the Elsevier homepage for full contact details (homepage details at the top of this page). Book Butler logo to search for more Elsevier books, visit the Books Butler at http://www.elsevier.com/homepage/ booksbutler/ ADVANCES IN THE BONDED COMPOSITE REPAIR OF METALLIC AIRCRAFT STRUCTURE Volume 2 Editors A.A. Baker Defence Science and Technology Organisation, Air Vehicles Division, Victoria, Australia L.R.F. Rose Department of Defence, Defence Science and Technology Organisation, Air Vehicles Division, Victoria, Australia R. Jones Mechanical Engineering Department, Monash University, Victoria, Australia 2002 ELSEVIER Amsterdam - Boston - London - New York - Oxford - Paris San Diego - San Francisco - Singapore - Sydney - Tokyo ELSEVIER SCIENCE Ltd The Boulevard, Langford Lane Kidlington, Oxford OX5 IGB, UK 0 2002 Elsevier Science Ltd. All rights reserved This work is protected under copyright by Elsevier Science, and the following terms and conditions apply to its use: Photocopying Single photocopies of single chapters may be made for personal use as allowed by national copyright laws. Permission of the Publisher and payment of a fee is required for all other photocopying, including multiple or systematic copying, copying for advertising or promotional purposes, resale, and all forms of document delivery. 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BIOGRAPHIES Dr. Alan Baker Dr. Alan Baker is Research Leader Aerospace Composite Structures, in Airframes and Engines Division, Defence Science and Technology (DSTO), Aeronautical and Maritime Research Laboratory and Technical Adviser to the Cooperative Research Centre-Advanced Composite Structures, Melbourne Australia. He is a Fellow of the Australian Academy of Technological Sciences and Engineering and an Adjunct Professor in Department of Aerospace Engineering, Royal Melbourne Institute of Technology. Dr. Baker is a member of the International Editorial Boards of the Journals Composites Part A Applied Science and Manufacturing, Applied Composites and International Journal of Adhesion and Adhesives. He is recognised for pioneering research work on metal-matrix fibre composites while at the Rolls Royce Advanced Research Laboratory. More recently, he is recognised for pioneering work on bonded composite repair of metallic aircraft components for which he has received several awards, including the 1990 Ministers Award for Achievement in Defence Science. Dr. Francis Rose Dr. Francis Rose is the Research Leader for Fracture Mechanics in Airframes and Engines Division, Defence Science and Technology (DSTO), Aeronautical and Maritime Research Laboratory. He has made important research contributions in fracture mechanics, non-destructive evaluation and applied mathematics. In particular, his comprehensive design study of bonded repairs and related crack- bridging models, and his contributions to the theory of transformation toughening in partially stabilised zirconia, have received international acclaim. His analysis of laser-generated ultrasound has become a standard reference in the emerging field of laser ultrasonics, and he has made seminal contributions to the theory of eddy- current detection of cracks, and early detection of multiple cracking. He is the Regional Editor for the International Journal of Fracture and a member of the editorial board of Mechanics of Materials. He was made a Fellow of the Institute of Mathematics and its Applications, UK, in 1987, and a Fellow of the Institution of Engineers, Australia, in 1994. He is currently President of the Australian Fracture Group, and has been involved in organising several local and international conferences in the areas of fracture mechanics and engineering mathematics. He currently serves on the Engineering Selection Panel of the Australian Research Council and of several other committees and advisory bodies. vi Biographies Professor Rhys Jones Professor Rhys Jones joined Monash University in early 1993 and is currently Professor of Mechanical Engineering, and Head of the Defence Science and Technology Organisation Centre of Expertise on Structural Mechanics. Professor Jones’ is best known for his in the fields of finite element analysis, composite repairs and structural integrity assessment. Professor Jones is the Founding Professor of both the BHP-Monash Railway Technology Institute and the BHP-Monash Maintenance Technology Institute. He is heavily involved with both Australian and overseas industry. In this context he ran the mechanical aspects of the Australian Governments Royal Commission into the failure at the ESSO plant in Victoria, and the Tubemakers-BHP investigation into the failure of the McArthur River gas pipe line in the Northern Territory. He is the recipient of numerous awards including the 1982 (Australian) Engineering Excellence Award, for composite repairs to Mirage 111, the Institution of Engineers Australia George Julius Medal, for contributions to failure analysis, a TTCP Award, for contributions to Australian, US, UK, Canada and NZ Defence Science in the field of composite structures, and a Rolls-Royce-Qantas Special Commendation, for his work on F-111 aircraft. Since 1999 Professor Jones has been Co-Chair of the International Conference (Series) on Composite Structures. Acknowledgement The editors are very pleased to acknowledge their appreciation of the great assistance provided by Drs Stephen Galea and Chun Wang of the Defence Science and Technology Organisation, Aeronautical and Maritime Research Laboratory, who made important contributions, in the collation and editing of this book. FOREWORD The introduction of the technology for bonded composite repairs of metallic airframe structures could not have come at a more opportune time. Today, many countries are facing the challenge of aging aircraft in their inventories. These airframes are degrading due to damage from fatigue cracking and corrosion. Repair with dependable techniques to restore their structural integrity is mandatory. The concept of using bonded composite materials as a means to maintain aging metallic aircraft was instituted in Australia approximately thirty years ago. Since that time it has been successfully applied in many situations requiring repair. These applications have not been limited to Australia. Canada, the United Kingdom, and the United States have also benefited from the use of this technology. The application for the solution of the problem of cracking in the fuel drain holes in wing of the C-141 is credited with maintaining the viability of this fleet. The concept for composite repair of metallic aircraft is simple. The bonded repair reduces stresses in the cracked region and keeps the crack from opening and therefore from growing. This is easy to demonstrate in a laboratory environment. It is another thing to do this in the operational environment where many factors exist that could adversely affect the repair reliability. The researchers at the Aeronautical and Maritime Research Laboratory in Australian realized there were many obstacles to overcome to achieve the desired reliability of the process. They also realized that failures of the repair on operational aircraft would mean loss of confidence and consequently enthusiasm for the process. They proceeded slowly. Their deliberate approach paid off in that they developed a process that could be transitioned to aircraft use by engineers and technicians. The essential ingredient for application of this technology is discipline. When the applicator of this process maintains the discipline required for the process and stays within the bounds of appropriate applications, then the repair will be successful. This book, edited by Drs A.A. Baker, L.R.F. Rose and R. Jones, includes the essential aspects of the technology for composite repairs. The editors have chosen some of the most knowledgeable researchers in the field of bonded repairs to discuss the issues with the many aspects of this technology. Included are discussions on materials and processes, design of repairs, certification, and application considerations. These discussions are sufficiently in-depth to acquaint the reader with an adequate understanding of the essential ingredients of the procedure. The application case histories are especially useful in showing the breadth of the possible uses of the technology. vii [...]... 1.7 1.8 1.9 1.10 Aim of book Classification of aircraft structures for inspection and repair Design and certification of airframe structures 1.2.1 Problems with ageing metallic airframe components 1.2.2 Repair requirements 1.3.1 Repair levels Repair procedures The case for adhesively bonded repairs Composite versus metallic patches Scope of applications Some experimental comparisons of bonding versus... mechanically fastened repairs to bonded composite repairs for ABDR 25.3.1 Adaptation of bonded composite repairs for battle damage 25.3.2 The composite laminating resin and adhesive 25.3.3 Fibre 765 766 766 767 xxiv 25.4 25.5 25.6 Contents 25.3.4 Simplified design methods for ABDR 25.3.5 Surface treatment 25.3.6 Forming the bonded composite patch 25.3.7 Mechanically fastened, metallic repair 25.3.8 Fatigue... resonant frequencies of the panel to frequencies well outside the recorded excitation frequencies In order to reduce the cost of repairing such cracked structures a bonded composite repair would be preferred The benefits of such a repair are reflected in the time required to carry out the repair For example, the inlet nacelle repair typically requires a repair time of 60 h for the mechanical repair and approximately... 15-25 h for the bonded repair In the case of the repair to the aft fuselage the time for the mechanical repair is 15-30 h spread over three or four days This repair also requires engine removal and installation which takes a three man team approximately 8 h followed by engine ground runs 53 1 Baker, A.A., Rose, L.R.F and Jones, R (eds.), Advances in the Bonded Composite Repairs of Metallic Aircraft Structure... 9.6 9.7 9.8 9.9 9.10 9.11 9.12 xvii 9.2.2 Repair of cracks in aircraft wing skin Initial design guidelines Comparison with experimental results for non rib stiffened panels Repair of thick sections 9.5.1 Experimental results Repair of cracked holes in primary structures Repair of cracked lugs 9.7.1 Numerical analysis 9.7.2 Experimental test 9.7.3 Discussion Repairs to interacting surface flaws Material... the bonded composite repair of metallic aircraft structure I Y557.500 I I I y566.m Y574.500 Y580500 I Y598.000 Fig 19.1 Location of the cracking in the lower nacelle inlet and the aft fuselage skins (Chemically milled fillets are indicated by dotted line.) A bonded repair was designed for the inlet nacelle area, based on a standard repair design procedure, and implemented on an existing cracked aircraft. .. analysis Repair options Design of the bonded repair FEM model of the patched crack Conclusions References Chapter 32 Case History: F-16 Fuel Vent-hole Repairs C Guijt and J Mazza 859 859 860 860 862 862 864 864 864 865 866 866 867 867 868 869 869 869 871 87 1 872 874 875 879 883 884 885 Introduction Damage tolerance analysis Repair options 32.3.1 Mechanically fastened aluminum patch Design of the bonded repair. .. Acknowledgements References Chapter 35 Case History: Repair Applications On DC-lO/MD-11 Aircraft D Roach 35.1 35.2 35.3 35.4 35.5 35.6 Introduction Repair development and validation tasks to support on -aircraft installation 35.2.1 Repair design Repair analysis Repair design validation Nondestructive inspection Current status of DC-lO/MD-l 1 commercial aircraft repairs Chapter 36 Case History: CF-116 Upper... design 37.6.3 Applicability of demonstrator programs Conclusions References Chapter 38 38.1 38.2 38.3 38.4 38.5 38.6 In-service Durability of Bonded Composite Repairs - Commercial Demonstrator Programs R.A Bartholomeusz and R.C Geddes Case History: Bonded Composite Repair of A CH-47 Cargo Hook Beam B.J Harkless, A.P Kerr and M.A Shupick Introduction Defect description Justification of approach 38.3.1 Loads... Risks to aircraft Quality management Facilities Training and certification Deficient repair concepts Conclusion References Chapter 25 Rapid Application Technology: Aircraft Battle Damage Repairs R Bartholomeusz, P Pearce and R Vodicka 76 1 25.1 25.2 761 762 762 763 '764 25.3 Introduction Aircraft battle damage repair 25.2.1 Battle damage 25.2.2 ABDR criteria 25.2.3 Types of ABDR Comparison of metallic . Bonded Comp Repair of Metallic Aircraft Structure VOLUME 2 A .7 Alan Baker Francis Rose Rhys Jones Edited by ECSEVIER ADVANCES IN THE BONDED COMPOSITE REPAIR OF METALLIC AIRCRAFT. solution of the problem of cracking in the fuel drain holes in wing of the C-141 is credited with maintaining the viability of this fleet. The concept for composite repair of metallic aircraft. Aim of book Classification of aircraft structures for inspection and repair 1.2.1. 1.2.2. Repair requirements 1.3.1. Repair levels Repair procedures The case for adhesively bonded repairs