Fatigue of Materials at Very High Numbers of Loading Cycles (eBook)
IX, 628 Seiten
Springer Fachmedien Wiesbaden (Verlag)
978-3-658-24531-3 (ISBN)
This book represents the final reports of the scientific projects funded within the DFG-SPP1466 and, hence, provides the reader with the possibility to familiarize with the leading edge of VHCF research. It draws a balance on the existing knowledge and its enhancement by the joint research action of the priority program. Three different material classes are dealt with: structural metallic materials, long-fiber-reinforced polymers and materials used in micro-electro-mechanical systems. The project topics address the development of suitable experimental techniques for high-frequency testing and damage monitoring, the characterization of damage mechanisms and damage evolution, the development of mechanism-based models and the transfer of the obtained knowledge and understanding into engineering regulations and applications.
Hans-Jürgen Christ is Full Professor of Materials Engineering at the University of Siegen, Germany. The main objective of his research is a detailed understanding of the behavior of metals and alloys under complex conditions representing those in technical service of engineering materials. The correlation of microscopic processes with the resulting macroscopic changes in properties is used to reveal the relevant mechanisms and damage processes, in order to develop a better prediction of the application limits and the expected lifetime of materials under service conditions.
Hans-Jürgen Christ is Full Professor of Materials Engineering at the University of Siegen, Germany. The main objective of his research is a detailed understanding of the behavior of metals and alloys under complex conditions representing those in technical service of engineering materials. The correlation of microscopic processes with the resulting macroscopic changes in properties is used to reveal the relevant mechanisms and damage processes, in order to develop a better prediction of the application limits and the expected lifetime of materials under service conditions.
Preface 5
Contents 7
1Fatigue of low alloyed carbon steels in the HCF/VHCF-regimes 10
Abstract 10
Keywords 10
1 Introduction 11
2 Materials and Experimental 12
2.1 Materials and Heat Treatment 12
2.2 Electromechanical Fatigue Setup 13
2.3 Ultrasonic Fatigue Setup 14
2.4 Microstructure Investigations 17
3 Results and Discussion 18
3.1 Influence of Pearlite Phase Fraction on the Fatigue Behaviour 18
3.2 Influence of Frequency 24
3.3 Influence of Heat Treatment 28
4 Summary and Conclusions 30
Acknowledgements 30
References 30
2Atomic-scale modeling of elementary processes during the fatigue of metallic materials: from crack initiation to crack-microstructure interactions 33
Abstract 33
Keywords 33
1 Methods 34
2 Methods 35
2.1 Interatomic potentials 36
2.2 Creation of tilt grain boundaries and dislocations 36
2.3 Setups for cracks 37
2.4 Setup for dislocation-crack interactions 39
2.5 Setup for crack initiation 39
3 Results and discussion 41
3.1 Properties of Fe and W potentials 41
3.2 Cracks in perfect single crystals 41
3.3 Fracture behavior of grain boundary cracks 44
3.3.1 Straight grain boundary cracks 44
3.3.2 Curved grain boundary cracks 45
3.4 Dislocation-crack interactions 46
3.5 Crack initiation at grain boundaries 48
3.6 Future directions: cyclic loading 50
4 Summary 52
Acknowledgements 53
References 53
3Fatigue behaviour of austenitic stainless steels in the VHCF regime 57
Abstract 57
Keywords 57
1 Introduction 58
2 Experimental details 61
3 Results and discussion 63
3.1 Fatigue behaviour of the 304L steel 63
3.2 Fatigue behaviour of the 316L steel 68
3.3 Fatigue behaviour of the 904L steel 71
3.4 Influence of the initial ?’ martensite volume fraction obtained by predeformation on the fatigue behaviour 73
4 Conclusions 77
Acknowledgements 78
References 78
4Simulation of the VHCF deformation of austenitic stainless steels and its effect on the resonant behaviour 80
Abstract 80
Keywords 80
1 Introduction 81
2 Experimental results 82
3 Simulation model 84
3.1 Shear band model 85
3.2 Martensitic transformation model 86
4 Numerical model 87
5 Simulation of cyclic plastic deformation of austenitic stainless steels 89
5.1 Cyclic plastic deformation of the metastable austenitic stainless steel 89
5.2 Cyclic plastic deformation of the stable austenitic stainless steel 91
5.3 Comparison of cyclic plastic deformation of the metastable and the stable austenitic stainless steel 92
5.4 Effect of initial martensite content in the microstructure on plastic sliding deformation 93
5.5 Temperature-dependent cyclic plastic deformation at low stress amplitudes 94
5.6 Influence of cyclic plastic deformation on the resonant behaviour 96
6 Conclusions 98
Acknowledgements 100
References 100
5Slip band formation and crack initiation during very high cycle fatigue of duplex stainless steel – Part 1: Mechanical testing and microstructural investigations 102
Abstract 102
Keywords 102
1 Introduction 103
2 Experimental details 104
2.1 Material and sample preparation 104
2.2 Test equipment and combination for in situ-observation 106
3 Results and discussion 108
3.1 Microstructural investigations 109
3.2 Influence of the atmosphere to fatigue life 113
4 Conclusion 115
Acknowledgements 116
References 116
6Fatigue mechanism and its modeling of an austenitic-ferritic duplex stainless steel under HCF and VHCF loading conditions 118
Abstract 118
Keywords 118
1 Introduction 119
2 Experimental and numerical details 120
2.1 Material, sample preparation and fatigue technique 120
2.2 Three dimensional microstructure reconstruction 122
2.3 Crystal plasticity 122
2.4 Model assumptions 123
3 Results 124
3.1 Fatigue life behavior and fatigue mechanisms 124
3.2 Simulation of fatigue crack nucleation in real microstructures 129
3.3 Simulation of short fatigue crack propagation in synthetic microstructures 132
4 Conclusions 136
Acknowledgements 137
References 137
7Influence of different loading stresses on the peak shape of X-ray rocking curves of an austenitic-ferritic duplex stainless steel during VHCF 139
Abstract 139
Keywords 139
1 Introduction 140
2 Experimental details 141
2.1 Material, sample geometry and fatigue technique 141
2.2 In-situ X-ray diffraction experiments 142
2.2.1 Vertical Setup 142
2.2.2 Horizontal Setup 143
3 Results 144
3.1 Example for intensity change 145
3.2 Example for position change 147
3.3 Example for combination of several changes 148
4 Conclusions 150
Acknowledgements 152
References 152
8Three-dimensional characterization of duplex stainless steel by means of synchrotron radiation X-ray diffraction imaging techniques 154
Abstract 154
Keywords 154
1 Introduction 155
2 Material and Methods 155
2.1 Microstructure of the investigated material 155
2.2 Grain microstructure reconstruction by X-ray diffraction imaging techniques 157
2.3 X-ray diffraction contrast tomography applied to duplex steel 318LN 160
2.3.1 Acquisition conditions 160
2.3.2 Reconstruction challenges related to the microstructure of duplex steel 160
2.3.3 Upgrade of the image formation model – 6D reconstruction framework 163
2.4 3D characterization of a propagating fatigue crack 165
3 Discussion 167
3.1 Challenges related to 3D imaging of fatigue cracks in the VHCF regime 167
3.2 Prospects and limitations of the 3D orientation mapping approach 168
4 Conclusions 169
Acknowledgements 170
References 170
9 Very high cycle fatigue crack initiation: investigation of fatigue mechanisms and threshold values for 100Cr6 172
Abstract 172
Keywords 172
1 Introduction 173
2 Material and experimental procedures 176
2.1 Material and specimen 176
2.2 Fatigue testing 177
2.3 Serial grinding 178
2.4 Analytical methods 179
2.4.1 Electron microscopy 179
2.4.2 Atom probe tomography 179
3 Fatigue results 181
3.1 S-N curve 181
3.2 Fracture surfaces 182
3.3 Fracture mechanics and threshold values 184
3.4 Serial grinding results 189
3.5 Change of crack initiation from surface to subsurface 190
4 Microstructural investigations 192
4.1 TEM 192
4.1.1 Fish-eye 192
4.1.2 FGA 193
4.1.3 FGA cracks prior failure 197
4.2 APT 198
4.2.1 Bulk 199
4.2.2 FGA at inclusions 201
4.2.3 FGA at artificial defects 206
5 New model for VHCF fracture mechanism 208
6 Conclusions 212
Acknowledgements 213
References 213
10Evaluation of multiple-flaw failure of bearing steel 52100 of different heats in the VHCF regime and mathematical determination of single-flaw behaviour 216
Abstract 216
Keywords 216
1 Introduction 217
2 Experimental 217
2.1 Material 217
2.3 Distribution of temperatures inside a specimen during a test 219
3 Fatigue test results 220
3.1 Fatigue life of the variants 220
3.2 Influence of specimens’ temperature on fatigue life 222
3.3 Failure origins 222
3.4 Preparation of the FGA by means of metallographic etching 226
3.5 Influence of mean stress on the occurrence frequency of failure types 227
4 Modelling of the single-flaw fatigue behaviour 229
4.1 Modelling of single-flaw finite life 230
4.2 Modelling of single-flaw fatigue limits 232
5 Summary 234
Acknowledgements 235
References 235
11Influence of near-surface stress gradients and strength effect on the very high cycle fatigue behavior of 42CrMo4 Steel 237
Abstract 237
Keywords 237
1 Introduction 238
2 Experimental procedures 239
2.1 Material and specimens 239
2.2 Testing equipment and procedure 240
3 Experimental Results and Discussion 241
3.1 Strength effect 241
3.1.1 Very High Cycle fatigue Resistance 241
3.2 Near surface stress gradient effect 250
3.2.1 Specimen without surface treatment 250
3.2.2 Specimen with surface treatment 251
3.2.3 Influence of residual stress 251
3.2.4 Evaluation of stress intensity factors 252
3.2.5 Influence of stress gradients 253
4 Conclusion / Outlook 254
Acknowledgements 254
References 255
12Fatigue behavior of X10CrNiMoV12-2-2 under the influence of mean loads and stress concentration factors in the very high cycle fatigue regime 257
Abstract 257
Keywords 257
1 Introduction 258
2 Material and Methods 260
2.1 Material 260
2.2 Ultrasonic fatigue testing setup 261
3 Results and discussion 262
3.1 Fatigue tests at smooth specimen 262
3.2 Fatigue tests at notched samples 266
3.3 Fracture- and FGA-formation mechanism 270
4 Conclusions 274
Acknowledgements 274
References 275
13Experimental and numerical investigations on crack initiation and crack growth under constant and variable amplitude loadings in the VHCF regime 277
Abstract 277
Keywords 277
1 Introduction 277
2 Experimental setup and material 278
3 Experimental results 280
3.1 Constant amplitude loading 280
3.2 Experiments with micro-notched specimens under constant amplitude loading 283
3.3 Variable amplitude loading 284
3.4 Fractography 287
4 Analytical investigations 289
4.1 Stress-based lifetime concepts 289
4.2 Fracture mechanical concepts 290
5 Numerical investigations 291
6 Conclusion 294
Acknowledgements 295
14Influence of ceramic particles and fibre reinforcement in metal-matrix-composites on the VHCF behaviour. Part I: Experimental investigations of fatigue and damage behaviour 298
Abstract 298
Keywords 298
1 Introduction 299
2 Experimental Details 300
2.1 Material Parameters 300
2.2 Mechanical Testing and Microstructural Characterization 302
2.3 Full-Field Measurements 304
3 Results and Discussion 305
3.1 General Placement 305
3.2 Fatigue Behaviour in the VHCF Regime 308
3.3 Evolution of Resonant Frequency, Damage Parameter and Temperature during Fatigue Loading 310
3.4 Correlated Fractography 312
3.5 Damage Mechanisms 314
3.6 Full Field Measurements for Characterization of Local Damage Behaviour 316
4 Conclusions 318
Acknowledgements 319
References 319
15Influence of ceramic particles and fibre reinforcement in metal matrix composites on the VHCF behaviour. Part II: Stochastic modelling and statistical inference 322
Abstract 322
Keywords 322
1 Introduction 323
2 Modelling the spatial configuration of ceramic reinforcements 325
2.1 Parametric model for the size-shape-orientation distribution of an reinforcement 325
2.2 Non-overlapping spheroid configurations 326
2.3 Additional local clustering 327
3 Modelling the fatigue lifetime 328
3.1 General assumptions 329
3.2 Individual lifetimes 330
3.2.1 Fracture of reinforcements 330
3.2.2 Interface debonding 331
3.3 Accumulating initiated projected areas 332
4 Estimating model parameters 334
4.1 General methodology 334
4.2 Fitting the spatial model 335
4.3 Fitting the lifetime model 336
5 Simulation study 336
5.1 General 336
5.2 Impact of orientation distribution 339
5.3 Impact of local clustering 340
6 Conclusion and outlook 342
Acknowledgements 343
References 343
16Development of a fatigue life prediction concept in the very high cycle fatigue range based on covariate microstructural features 346
Abstract 346
Keywords 346
1 Introduction 347
2Material and experimental details 348
2.1 Nimonic 80A (material group I) 348
2.2 AISI 304 (Material group II) 349
3 Fatigue results and discussion 350
3.1 Nimonic 80A (material group I) 350
3.1.1 Average grain diameter 20 ?m 350
3.1.2 Average grain diameter 32 and 60 ?m 353
3.1.3 Analytical description of stress concentration at twin boundaries 354
3.1.4 Quantitative description of stress concentration at regular grain boundaries 355
3.2 AISI 304 (material group II) 357
4 Creating a database for statistical fatigue life predictions 359
4.1 Nimonic 80A (material group I) 359
4.2 AISI 304 (material group II) 360
5 Prediction of fatigue life 362
5.1 Nimonic 80A (material group I) 362
5.2 AISI 304 (material group II) 364
6 Summary 366
Acknowledgements 367
References 367
17Experimental investigation of damage detection and crack initiation up to the very high cycle fatigue regime 368
Abstract 368
Keywords 368
1 Introduction 368
2 Custom-built resonant fatigue setup 370
2.1 Experimental principle and sample geometry 370
2.2 Implementation of the resonant fatigue setup 371
2.3 Damage detection by means of sample resonant frequency tracking 374
2.4 High-throughput method: In-situ optical method coupled with EBSD and DDD 374
2.5 Sample preparation 377
2.6 Bcc Material 17-4PH 377
3 Observation of damage initiation, and crack initiation 382
3.1 Damage detection method 382
3.2 First damage: slip bands 383
3.3 Identification of the first extrusion location with the optical in-situ camera system 384
3.4 Second phase: crack initiation 389
3.5 Third phase: crack propagation 391
3.6 Fatigue data 391
3.7 Runout pattern 391
4 Experimental input for crack initiation model 393
5 Conclusion 395
Acknowledgements 395
References 395
18Discrete dislocation dynamics study of dislocation microstructure during cyclic loading 397
Abstract 397
Keywords 397
1 Introduction 397
1.1 Discrete Dislocation Dynamics 399
1.2 Dislocation network analysis: graphs and shape characteristics 400
1.3 Surface roughness 402
2 Results and Discussion 402
2.1 Role of Burgers vector orientation with respect to surface: single dislocation 402
2.2 Role of the grain shape and surface vicinity 408
2.3 Role of plastic strain amplitude on irreversibility measures: random initial dislocation structure 408
2.3.1 Dislocation density evolution 410
2.3.2 Surface roughness 411
2.4 Microstructure evolution under cyclic loading 414
3 Conclusion 416
Acknowledgements 417
References 417
19Investigation of the infinite life of fibre-reinforced plastics using X-ray refraction topography for the in-situ, non-destructive evaluation of micro-structural degradation processes during cyclic fatigue loading 419
Abstract 419
Keywords 419
1 Introduction 419
2 Experimental 421
2.1 Materials and test specimens 421
2.2 X-ray refraction technique 421
2.3 Set-up of the SAXS fatigue-testing apparatus 422
2.4 Parameter setting of the SAX-measuring method 424
2.5 Examination of different epoxy matrix systems 425
2.6 Comparative tests on GFRP 427
2.7 Evolution of refraction and crack density in the tensile strength test on CFRP 430
2.8 Damage evaluation by in-situ SAXS during fatigue tests on CFRP 432
2.9 Microscopic examinations 437
3 Concept for prediction of damage initiation based on equivalent stress in the matrix 438
4 Discussion and Conclusion 439
Acknowledgements 440
References 440
20Very high cycle fatigue of carbon fiber reinforced polyphenylene sulfide at ultrasonic frequencies 442
Abstract 442
Keywords 442
1 Introduction and motivation for VHCF testing of CFRP 442
2 Development and main principle of ultrasonic fatigue testing for polymer composites 443
3 Investigated composites and specimen design for VHCF testing 445
4 Experimental results 447
4.1 3D-Scanning Laser vibrometry 447
4.2 Online thermography 448
4.3 Constant amplitude tests in the VHCF regime 449
4.4 Microscopic analysis of failure mechanisms of CF-PPS for VHCF loading 450
4.5 3D fatigue damage distribution of CF-PPS 453
4.6 Surface crack density and stiffness degradation of CF-PPS in the VHCF-regime 454
4.7 Fatigue damage states of CF-PPS in the VHCF regime 457
5 Summary and concluding remarks 459
Acknowledgements 460
References and further reading 460
21Acoustics based assessment of a composite material under very high cycle fatigue loading 463
Abstract 463
Keywords 463
1 Introduction 464
2 Results 465
2.1 Material and test set-up 465
2.2 NDT offline characterisation 467
2.3 Data analysis 472
2.3.1 Nonlinear ultrasonic analysis 472
2.3.2 Measures of non-linearity using advanced signal processing methods 477
2.3.2.1 Short Time Fourier Transformation (STFT) 477
2.3.2.2 Distortion factor 478
2.3.2.3 Damage index measures 478
2.3.3 Inverse approach for quantification of the damage 481
3 Conclusion 483
Acknowledgements 483
References 484
22Methodology for the high-frequency testing of fiber-reinforced plastics 486
Abstract 486
Keywords 486
1 Introduction 487
2 High-frequency-testing techniques 488
2.1 Classical systems 488
2.2 Resonance pulsator 488
2.3 Resonant continuum resonators 489
2.4 Single-mass resonator 490
2.5 Dual-mass resonator 492
2.6 Non-linear behavior and maximum strain 495
3 Specimen material and specimen design for resonant testing 498
3.1 Specimen material 498
3.2 Specimen design 499
3.3 Production of tubular specimens 501
4 High-frequency resonator control 502
5 VHCF testing results 503
5.1 Validity of high-frequency testing 504
6 Conclusion 505
Acknowledgements 507
References 508
23Very high cycle fatigue testing and behavior of GFRP cross-and angle-ply laminates 509
Abstract 509
Keywords 509
1 Introduction 509
2 Experimental Methods and Testing Equipment 511
2.1 Methodology for effective VHCF Testing – The VHCF Bending Test Rig 511
2.2 Quasi-static Bending Tests 514
2.3 Damage Evaluation 515
2.4 Materials and Specimen Preparation 515
3 Very High Cycle Fatigue Behavior of GFRP Laminates 516
3.1 Experimental Procedure and Data Evaluation 517
3.2 Fatigue Load Levels 517
3.3 Fatigue of the Cross-Ply Laminate [90/0]s 518
3.4 Fatigue of the Angle-Ply Laminate [±45]s 521
3.5 Mastercurve Approach for Crack Initiation 524
4 Numerical Modelling 524
4.1 Stiffness Degradation Analysis 524
4.2 Analysis of Weak Area Cracking 525
5 Conclusion 527
Acknowledgements 528
References 528
24A physically based fatigue damage model for simulating three-dimensional stress states in composites under very high cycle fatigue loading 531
Abstract 531
Keywords 531
1 Introduction 532
1.1 Overview of the fatigue damage model (FDM) 533
1.2 Background and theory of FDM 533
1.3 Hypothesis 535
1.4 Quasi-static stress-strain curves 536
1.5 Failure criterion 537
1.6 Strain evolution under fatigue loading 538
1.7 Appropriate S/N-curves 539
2 Extension of the 2D FDM to 3D 540
2.1 Extension of the stiffness tensor to a 3D stress state 540
2.2 Extension of Puck’s failure criterion to the 3D framework 543
3 Validation 545
3.1 Validation and comparison of the extended Puck’s criterion to the static 2D FDM 545
3.2 Validation and comparison of the results of cyclic part of 2D FDM to 3D FDM 547
4 Concluding remarks 554
Acknowledgements 555
References 555
25Investigation of the fatigue behaviour of carbon fibre reinforced plastics due to micro-damage and effects of the micro-damage on the ply strengths in the very high cycle fatigue regime 558
Abstract 558
Keywords 558
1 Introduction 559
2 Damage mechanisms in CFRP under transverse loads 560
2.1 Experimental investigation on micro-damage initiation and evolution under transverse loads 560
2.1.1 Extraction of damage evolution using AE and clustering 560
2.1.1.1 A novel clustering approach 561
2.1.1.2 Choice of signal feature for clustering 562
2.1.2 Damage evolution and effect of testing conditions 563
2.2 Modelling damage onset and progression 566
2.2.1 Experimental determination of interfacial properties 567
2.2.1.1 Determination of the failure mechanisms 567
3 Fatigue damage of FRP 573
3.1 Test set up and strategy 573
3.2 Fatigue behaviour under transversal loads 573
3.3 Interaction of fatigue damage with the strengths boundaries 575
3.3.1 Effect of cyclical preloading on the longitudinal compressive strength 575
3.3.2 Effect of preloading on the transverse strength 577
4 Conclusion and summary 578
Acknowledgements 579
References 579
26Damage initiation and failure mechanisms of carbon nanoparticle modified CFRP up to very high cycle fatigue-loading 581
Abstract 581
Keywords 581
1 Introduction 582
2 Experimental 583
2.1 Materials and specimen preparation 583
2.2 Mechanical test procedure 584
3 Results 585
3.1 Mechanical properties 585
3.2 Fatigue behaviour 586
3.3 Fracture Toughness 590
3.4 Fractography 591
4 Discussion 597
5 Conclusion 599
Acknowledgements 600
References 600
27Characterisation and modelling of the inter-fibre cracking behaviour of CFRP up to very high cycles 603
Abstract 603
Keywords 603
1 Introduction 603
2 VHCF test stand 604
2.1 General design approach 604
2.2 Analytical design optimisation 605
2.3 Numerical validation 607
2.4 Measurement and control 609
3 Experimental procedure 611
3.1 Material and specimen design 611
3.2 Quasi-static bending experiments 612
3.3 Fatigue bending experiments 614
4 Modelling the inter-fibre cracking behaviour 615
4.1 Calculation of the mechanical strain energy release rate 616
4.2 Modelling the crack density evolution under quasi-static loading (cstatic) 617
4.3 Modelling the cyclic crack growth (ccyclic) 618
4.4 Prediction of transverse cracking behaviour 620
5 Conclusion and outlook 621
Acknowledgements 623
References 623
| Erscheint lt. Verlag | 19.11.2018 |
|---|---|
| Zusatzinfo | IX, 628 p. 1 illus. |
| Verlagsort | Wiesbaden |
| Sprache | englisch |
| Themenwelt | Technik ► Maschinenbau |
| Schlagworte | Fatigue Damage Accumulation • Fatigue Limit • Infinite Life of Materials • Ultrasonic Fatigue Testing • Very High Cycle Fatigue (VHCF) |
| ISBN-10 | 3-658-24531-X / 365824531X |
| ISBN-13 | 978-3-658-24531-3 / 9783658245313 |
| Informationen gemäß Produktsicherheitsverordnung (GPSR) | |
| Haben Sie eine Frage zum Produkt? |
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