DOT/FAA/TC-18/6 Probabilistic Design for Federal Aviation Administration William J. Hughes Technical Center Rotor Integrity Aviation Research Division Atlantic City International Airport New Jersey 08405 October 2018 Final Report This document is available to the U.S. public through the National Technical Information Services (NTIS), Springfield, Virginia 22161. This document is also available from the Federal Aviation Administration William J. Hughes Technical Center at actlibrary.tc.faa.gov. U.S. Department of Transportation Federal Aviation Administration NOTICE This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The U.S. Government assumes no liability for the contents or use thereof. The U.S. Government does not endorse products or manufacturers. Trade or manufacturers’ names appear herein solely because they are considered essential to the objective of this report. The findings and conclusions in this report are those of the author(s) and do not necessarily represent the views of the funding agency. This document does not constitute FAA policy. Consult the FAA sponsoring organization listed on the Technical Documentation page as to its use. This report is available at the Federal Aviation Administration William J. Hughes Technical Center’s Full-Text Technical Reports page: actlibrary.tc.faa.gov in Adobe Acrobat portable document format (PDF). Technical Report Documentation Page 1. Report No. 2. Government Accession No. 3. Recipient's Catalog No. DOT/FAA/TC-18/6 4. Title and Subtitle 5. Report Date October 2018 PROBABILISTIC DESIGN FOR ROTOR INTEGRITY 6. Performing Organization Code 7. Author(s) 8. Performing Organization Report No. R. Craig McClung* Jonathan P. Moody* Jonathan P. Dubke† 18-11481 Michael P. Enright* Simeon H. K. Fitch** Robert J. Maffeo†† Yi-Der Lee* Harry R. Millwater*** Michael E. McClure††† Wuwei Liang* Alonso D. Peralta†††† 9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) * Southwest Research Institute® † Rolls-Royce Corporation 6220 Culebra Road 2001 South Tibbs Avenue San Antonio, TX 78238 Indianapolis, IN 46241 ** Elder Research, Inc. †† GE Aviation 300 West Main Street #301 1 Neumann Way Charlottesville, VA 229031 Cincinnati, OH 45215 *** University of Texas at San Antonio ††† Pratt & Whitney 6900 North Loop 1604 West 400 Main Street San Antonio, TX 78249 East Hartford, CT 06108 †††† Honeywell th 11. Contract or Grant No. 111 South 34 Street Phoenix, AZ 85072 2005-G-005 12. Sponsoring Agency Name and Address 13. Type of Report and Period Covered U.S. Department of Transportation Final Report Federal Aviation Administration April 2005 – August 2011 FAA New England Regional Office 14. Sponsoring Agency Code 1200 District Ave Burlington, MA 01803 AIR-6A1 15. Supplementary Notes The FAA William J. Hughes Technical Center Aviation Research Division Technical Monitor was Joseph Wilson. 16. Abstract This grant supported the efforts of the FAA to develop an enhanced life-management process, based on probabilistic damage- tolerance principles, to address the threat of material or manufacturing anomalies in high-energy rotating components of aircraft engines. Specific outcomes of the grant included enhanced predictive tool capability and supplementary material/anomaly behavior characterization and modeling. The efforts facilitate implementation of official advisory material for circular holes and support evolving methods for surface damage analysis of attachment slots and turned surfaces, while also developing improved analysis methods for inherent anomalies in all materials. Major research products included improved crack-growth life-prediction models and supporting experimental data, new methods for fracture mechanics characterization of cracks in rotors, automated methods for integrity and reliability assessment of actual components, and multiple new versions of the DARWIN® computer code for technology transfer to industry and the FAA. 17. Key Words 18. Distribution Statement Aircraft gas turbine engines, Disks, Rotors, Low cycle fatigue, This document is available to the U.S. public through the Fracture mechanics, Probabilistic damage tolerance, Risk National Technical Information Service (NTIS), Springfield, assessment, Surface damage, DARWIN Virginia 22161. 19. Security Classif. (of this report) 20. Security Classif. (of this page) 21. No. of Pages 22. Price Unclassified Unclassified 312 Form DOT F 1700.7 (8-72) Reproduction of completed page authorized ACKNOWLEDGEMENTS Successful completion of this large, multidisciplinary research project would not have been possible without the significant contributions and assistance of many different people. Some are named as authors in this report, and many others deserve special mention. Special appreciation is extended to the FAA employees and consultants who provided sustained support, encouragement, and guidance throughout the project. Heartfelt thanks goes to Tim Mouzakis of the Engine and Propeller Directorate in the New England Regional Office, Joe Wilson of the William J. Hughes Technical Center, and FAA consultants Jon Bartos and Nick Provenzano. The entire project was motivated and guided by the Rotor Integrity Sub-Committee of the Aerospace Industries Association, led by current chairman Michael Gorelik and previous chairman Bill Knowles, both from Honeywell. Direct leadership was provided by the industry Steering Committee comprising representatives from the four partner companies: GE Aviation (GEA), Honeywell, Pratt & Whitney (P&W), and Rolls-Royce® Corporation (RRC). Current members are chair Jon Dubke (RRC), Mike McClure (P&W), Alonso Peralta (Honeywell), and Bob Maffeo (GEA). Previous members during the term of this program include former chair Darryl Lehmann and Johnny Adamson (both from P&W), Jon Tschopp (GEA), and Ahsan Jameel and Michael Gorelik (both from Honeywell). The development of high-temperature crack-growth methods was guided by an informal advisory team comprised of Bob Van Stone (formerly GEA), Barney Lawless (GEA), Rick Pettit (formerly P&W), Fashang Ma (P&W), Tom Cook and David Mills (RRC), and Youri Lenets and Terry Richardson (Honeywell). Barney Lawless and Bob Van Stone led the time-dependent crack-growth program at GEA, with additional methods help from Sue Gilbert. Fashang Ma led the investigation of alternative analysis methods for time-dependent crack growth at P&W. James Hartman and Gil Mora led fatigue crack-growth testing activities at Honeywell. Yi-Der Lee (Southwest Research Institute®, SwRI®) performed all development activities for the Flight_Life fracture mechanics module, including generating all stress intensity factor solutions. Craig McClung and Vikram Bhamidipati (both from SwRI) performed the small-crack study. Special appreciation is extended to Mike Caton (Air Force Research Laboratory, AFRL), Sushant Jha (AFRL), Youri Lenets (Honeywell), Jack Telesman (NASA Glenn Research Center, GRC), and Jim Newman (Mississippi State University) for generously providing their data from other projects and answering many questions. Additional financial support for analysis of the U-720 data was provided by NASA GRC through Contract No. NNC08CB06C (Jack Telesman, project monitor). DARWIN development was led by Michael Enright (SwRI), with substantial support from Wuwei Liang (SwRI) and Luc Huyse (formerly SwRI). Jonathan Moody (SwRI) and Chris Waldhart (formerly SwRI) led DARWIN testing and validation activities. Simeon Fitch, Ben Guseman, and iii Ben Hocking (all Elder Research, formerly known as Mustard Seed Software) performed all graphical user interface development for DARWIN. Steve Schrantz and Bob McClain (both GEA) provided assistance with finite element method model translation. Harry Millwater and his students and colleagues provided additional DARWIN support at the University of Texas at San Antonio. Those contributors included Jonathan Moody, Wesley Osborn, Faiyazmehadi Momin, Gulshan Singh, and Tony Castaldo. The partner companies provided extensive evaluation and testing of new DARWIN releases throughout the program. Key contributors included Mike Hartle (GEA); Alonso Peralta (Honeywell) and Ahsan Jameel (formerly Honeywell); Jon Dubke, Jason Baker, Justin Gilman, and Doug Olsen (all RRC); and Darryl Lehmann and Mike McClure (both P&W). Birdie Matthews (SwRI) provided superlative clerical assistance in preparing this large final report. Gerry Leverant (SwRI consultant) is thanked for his careful peer review of the report. iv TABLE OF CONTENTS Page EXECUTIVE SUMMARY xvi 1. INTRODUCTION 1 1.1 Background 1 1.2 Organization of Research 5 2. ADVANCED DAMAGE TOLERANCE METHODS 6 2.1 Time-Dependent Fatigue Crack Growth 6 2.1.1 Superposition Models 6 2.1.2 Retardation Models 10 2.2 Non-Isothermal Fatigue Crack Growth 11 2.2.1 Use of Isothermal Fatigue Crack Growth Properties for Non-Isothermal Cycling 11 2.2.2 Time-Dependent Shakedown During Non-Isothermal Crack Growth 12 2.3 Small Fatigue Cracks 12 2.4 Nickel Anomaly Fatigue Testing 14 2.5 Benchmark Fatigue Crack Growth Data 15 3. ADVANCED FRACTURE ANALYSIS 16 3.1 New and Enhanced Stress Intensity Factor Solutions 16 3.1.1 New Bivariant SIF Solution for Semi-Elliptical Surface Crack in Plate 16 3.1.2 Extension of Validity Limits for Univariant SIF for Semi-Elliptical Surface Crack in Plate 17 3.1.3 Improved Integration Methods for Bivariant SIF Solutions 18 3.1.4 Pre-Integration Methods for Univariant SIF Solutions 18 3.1.5 New Univariant SIF Solution for Through