Is there a fatigue limit in metals? This question is the main focus of this book. Written by a leading researcher in the field, Claude Bathias presents a thorough and authoritative examination of the coupling between plasticity, crack initiation and heat dissipation for lifetimes that exceed the billion cycle, leading us to question the concept of the fatigue limit, both theoretically and technologically. This is a follow-up to the Fatigue of Materials and Structures series of books previously published in 2011. Contents 1. Introduction on Very High Cycle Fatigue. 2. Plasticity and Initiation in Gigacycle Fatigue. 3. Heating Dissipation in the Gigacycle Regime. About the Authors Claude Bathias is Emeritus Professor at the University of Paris 10-La Defense in France. He started his career as a research engineer in the aerospace and military industry where he remained for 20 years before becoming director of the CNRS laboratory ERA 914 at the University of Compi gne in France. He has launched two international conferences about fatigue: International Conference on the Fatigue of Composite Materials (ICFC) and Very High Cycle Fatigue (VHCF). This new, up-to-date text supplements the book Fatigue of Materials and Structures, which had been previously published by ISTE and John Wiley in 2011. A thorough review of coupling between plasticity, crack priming, and thermal dissipation for lifespans higher than a billion of cycle has led us to question the concept of fatigue limit, from both the theoretical and technological point of view. This book will address that and more.

Is there a fatigue limit in metals? This question is the main focusof this book.Written by a leading researcher in the field, Claude Bathiaspresents a thorough and authoritative examination of the couplingbetween plasticity, crack initiation and heat dissipation forlifetimes that exceed the billion cycle, leading us to question theconcept of the fatigue limit, both theoretically andtechnologically.This is a follow-up to the Fatigue of Materials and Structuresseries of books previously published in 2011.Contents1. Introduction on Very High Cycle Fatigue.2. Plasticity and Initiation in Gigacycle Fatigue.3. Heating Dissipation in the Gigacycle Regime.About the AuthorsClaude Bathias is Emeritus Professor at the University of Paris10-La Defense in France. He started his career as a researchengineer in the aerospace and military industry where he remainedfor 20 years before becoming director of the CNRS laboratory ERA914 at the University of Compiègne in France. He has launchedtwo international conferences about fatigue: InternationalConference on the Fatigue of Composite Materials (ICFC) and VeryHigh Cycle Fatigue (VHCF).This new, up-to-date text supplements the book Fatigue ofMaterials and Structures, which had been previously publishedby ISTE and John Wiley in 2011. A thorough review of couplingbetween plasticity, crack priming, and thermal dissipation forlifespans higher than a billion of cycle has led us to question theconcept of fatigue limit, from both the theoretical andtechnological point of view. This book will address that and more.

ACKNOWLEDGEMENTS viiCHAPTER 1. INTRODUCTION ON VERY HIGH CYCLE FATIGUE 11.1. Fatigue limit, endurance limit and fatigue strength 11.2. Absence of an asymptote on the SN curve 51.3. Initiation and propagation 61.4. Fatigue limit or fatigue strength 71.5. SN curves up to 109 cycles 81.6. Deterministic prediction of the gigacycle fatiguestrength 101.7. Gigacycle fatigue of alloys without flaws 121.8. Initiation mechanisms at 109 cycles 131.9. Conclusion 131.10. Bibliography 14CHAPTER 2. PLASTICITY AND INITIATION IN GIGACYCLEFATIGUE 172.1. Evolution of the initiation site from LCF to GCF 172.2. Fish-eye growth 202.2.1. Fracture surface analysis 202.2.2. Plasticity in the GCF regime 232.3. Stresses and crack tip intensity factors around sphericaland cylindrical voids and inclusions 292.3.1. Spherical cavities and inclusions 292.3.2. Spherical inclusion 312.3.3. Mismatched inclusion larger than the spherical cavity itoccupies 312.3.4. Cylindrical cavities and inclusions 332.3.5. Cracking from a hemispherical surface void 352.3.6. Crack tip stress intensity factors for cylindricalinclusions with misfit in both size and material properties 382.4. Estimation of the fish-eye formation from theParis-Hertzberg law 422.4.1. "Short crack" number of cycles 472.4.2. "Long crack" number of cycles 482.4.3. "Below threshold" number ofcycles 482.5. Example of fish-eye formation in a bearingsteel 492.6. Fish-eye formation at the microscopic level 522.6.1. Dark area observations 532.6.2. "Penny-shaped area" observations 542.6.3. Fracture surface with large radial ridges 562.6.4. Identification of the models 592.6.5. Conclusion 622.7. Instability of microstructure in very high cycle fatigue(VHCF) 622.8. Industrial practical case: damage tolerance at 109 cycles692.8.1. Fatigue threshold in N18 702.8.2. Fatigue crack initiation of N18 alloy 712.8.3. Mechanisms of the GCF of N18 alloy 732.9. Bibliography 74CHAPTER 3. HEATING DISSIPATION IN THE GIGACYCLEREGIME 773.1. Temperature increase at 20 kHz 773.2. Detection of fish-eye formation 813.3. Experimental verification of Nf by thermaldissipation 833.4. Relation between thermal energy and cyclic plastic energy853.5. Effect of metallurgical instability at the yield point inultrasonic fatigue 893.6. Gigacycle fatigue of pure metals 913.6.1. Microplasticity in the ferrite 953.6.2. Effect of gigacycle fatigue loading on the yield stressin Armco iron 973.6.3. Temperature measurement on Armco iron 983.6.4. Intrinsic thermal dissipation in Armco iron 1023.6.5. Analysis of surface fatigue crack on iron 1053.7. Conclusion 1093.8. Bibliography 110INDEX 113