NTIS # PB2012- SSC-462 REVIEW OF CURRENT PRACTICES OF FRACTURE REPAIR PROCEDURES FOR SHIP STRUCTURES This document has been approved For public release and sale; its Distribution is unlimited SHIP STRUCTURE COMMITTEE 2012 Ship Structure Committee RADM P.F. Zukunft RDML Thomas Eccles U. S. Coast Guard Assistant Commandant, Chief Engineer and Deputy Commander Assistant Commandant for Marine Safety, Security For Naval Systems Engineering (SEA05) and Stewardship Co-Chair, Ship Structure Committee Co-Chair, Ship Structure Committee Mr. H. Paul Cojeen Dr. Roger Basu Society of Naval Architects and Marine Engineers Senior Vice President American Bureau of Shipping Mr. Christopher McMahon Mr. Victor Santos Pedro Director, Office of Ship Construction Director Design, Equipment and Boating Safety, Maritime Administration Marine Safety, Transport Canada Mr. Kevin Baetsen Dr. Neil Pegg Director of Engineering Group Leader - Structural Mechanics Military Sealift Command Defence Research & Development Canada - Atlantic Mr. Jeffrey Lantz, Mr. Edward Godfrey Commercial Regulations and Standards for the Director, Structural Integrity and Performance Division Assistant Commandant for Marine Safety, Security and Stewardship Dr. John Pazik Mr. Jeffery Orner Director, Ship Systems and Engineering Research Deputy Assistant Commandant for Engineering and Division Logistics SHIP STRUCTURE SUB-COMMITTEE AMERICAN BUREAU OF SHIPPING (ABS) DEFENCE RESEARCH & DEVELOPMENT CANADA ATLANTIC Mr. Craig Bone Dr. David Stredulinsky Mr. Phil Rynn Mr. John Porter Mr. Tom Ingram MARITIME ADMINISTRATION (MARAD) MILITARY SEALIFT COMMAND (MSC) Mr. Chao Lin Mr. Michael W. Touma Mr. Richard Sonnenschein Mr. Jitesh Kerai NAVY/ONR / NAVSEA/ NSWCCD TRANSPORT CANADA Mr. David Qualley / Dr. Paul Hess Natasa Kozarski Mr. Erik Rasmussen / Dr. Roshdy Barsoum Luc Tremblay Mr. Nat Nappi, Jr. Mr. Malcolm Witford UNITED STATES COAST GUARD SOCIETY OF NAVAL ARCHITECTS AND MARINE ENGINEERS (SNAME) CAPT John Nadeau Mr. Rick Ashcroft CAPT Paul Roden Mr. Dave Helgerson Mr. Jaideep Sirkar Mr. Alex Landsburg Mr. Chris Cleary Mr. Paul H. Miller CONVERSION FACTORS (Approximate conversions to metric measures) To convert from to Function Value LENGTH inches meters divide 39.3701 inches millimeters multiply by 25.4000 feet meters divide by 3.2808 VOLUME cubic feet cubic meters divide by 35.3149 cubic inches cubic meters divide by 61,024 SECTION MODULUS inches2 feet2 centimeters2 meters2 multiply by 1.9665 inches2 feet2 centimeters3 multiply by 196.6448 inches4 centimeters3 multiply by 16.3871 MOMENT OF INERTIA inches2 feet2 centimeters2 meters divide by 1.6684 inches2 feet2 centimeters4 multiply by 5993.73 inches4 centimeters4 multiply by 41.623 FORCE OR MASS long tons tonne multiply by 1.0160 long tons kilograms multiply by 1016.047 pounds tonnes divide by 2204.62 pounds kilograms divide by 2.2046 pounds Newtons multiply by 4.4482 PRESSURE OR STRESS pounds/inch2 Newtons/meter2 (Pascals) multiply by 6894.757 kilo pounds/inch2 mega Newtons/meter2 multiply by 6.8947 (mega Pascals) BENDING OR TORQUE foot tons meter tons divide by 3.2291 foot pounds kilogram meters divide by 7.23285 foot pounds Newton meters multiply by 1.35582 ENERGY foot pounds Joules multiply by 1.355826 STRESS INTENSITY kilo pound/inch2 inch½(ksi√in) mega Newton MNm3/2 multiply by 1.0998 J-INTEGRAL kilo pound/inch Joules/mm2 multiply by 0.1753 kilo pound/inch kilo Joules/m2 multiply by 175.3 SR 1459 TABLE OF CONTENTS 1 INTRODUCTION........................................................................................................................ 1-1 1.1 USCG NVIC 7-68........................................................................................ 1-1 1.2 Development over the Past Four Decades ................................................... 1-2 1.3 Scope of Work ............................................................................................. 1-4 1.4 Organization of the Report........................................................................... 1-4 2 GENERAL GUIDANCE OF FRACTURE REPAIRS ................................................................ 2-1 2.1 General Principles........................................................................................ 2-1 2.2 General Guidance......................................................................................... 2-1 2.3 Location of Fractures ................................................................................... 2-2 2.4 Criticality of Fractures ................................................................................. 2-2 2.5 Fracture Threshold Criteria.......................................................................... 2-4 2.6 Fracture Repair Option ................................................................................ 2-4 2.7 Design Modification as Permanent Repair .................................................. 2-5 3 TECHNICAL BACKGROUND .................................................................................................. 3-1 3.1 Terminologies .............................................................................................. 3-1 3.2 USCG, Class and Owner.............................................................................. 3-1 3.3 Repair Plan................................................................................................... 3-2 3.4 Material of Steel........................................................................................... 3-4 3.5 Nondestructive Testing (NDT) .................................................................... 3-8 3.6 Qualification of Welders and NDT Personnel............................................. 3-9 4 ABS AND INDUSTRY EXPERIENCES WITH FRACTURES ................................................ 4-1 4.1 Areas Prone to Fractures in Oil Carriers...................................................... 4-2 4.2 Areas Prone to Fractures in Bulk Carriers ................................................... 4-4 4.3 Areas Prone to Fractures in Container Carriers ........................................... 4-6 4.4 Conclusions.................................................................................................. 4-8 5 CLASSIFYING STRUCTURAL FAILURES............................................................................. 5-1 5.1 USCG CAIP Scheme for Classing Structural Failures................................ 5-1 5.2 Generic Scheme for Assigning Criticality Classes ...................................... 5-3 5.3 Conclusions.................................................................................................. 5-9 6 FRACTURE THRESHOLD CRITERIA..................................................................................... 6-1 6.1 Fracture Mechanics...................................................................................... 6-1 6.2 Fracture Mechanics Methodology Specified by USCG CAIP .................... 6-2 6.3 Industry Standard for Fracture Mechanics Calculations.............................. 6-3 6.4 Research on Fracture Mechanics Applications............................................ 6-4 6.5 Challenges.................................................................................................... 6-5 6.6 Summary and Recommendations ................................................................ 6-6 7 FRACTURE REPAIR TECHNIQUES........................................................................................ 7-1 7.1 Gap Analysis................................................................................................ 7-1 7.2 Welding........................................................................................................ 7-6 7.3 Repair Techniques ....................................................................................... 7-7 v SR 1459 7.4 Design Modification .................................................................................. 7-13 7.5 Recommendations...................................................................................... 7-13 Appendix A. Steel Grades and Properties Specified by IACS ................................................................. A-1 Appendix B Welding Consumables ..........................................................................................................B-1 Appendix C Industry Experiences With Fracture Repairs ........................................................................C-1 Appendix D Repair Suggestion Examples Based on IACS Rec. No. 96, 84 and 76................................ D-1 Appendix E Criticality Classes for Structural Failures .............................................................................E-1 ABBREVIATIONS ................................................................................................................................... I USEFUL WEB LINKS.............................................................................................................................II PUBLICATIONS OF ABS, IACS, TSCF, USGC ................................................................................. IV REFERENCES ....................................................................................................................................... VI PROJECT TEAM AND SSC PROJECT TECHNICAL COMMITTEE ............................................... IX Attachment A. USCG NVIC 7-68 Notes on Inspection and Repair of Steel Hulls Attachment B. USCG Critical Areas Inspection Plans • USCG NVIC 15-91 Critical Areas Inspection Plans (CAIPs) • USCG