Computational Methods for Predicting Material Processing Defects (eBook)

Proceedings of the International Conference on Computational Methods for Predicting Material Processing Defects, September 8-11, 1987, Cachan, France

M. Predeleanu (Herausgeber)

eBook Download: PDF

2014 | 1. Auflage
372 Seiten
Elsevier Science (Verlag)
978-1-4832-9849-8 (ISBN)

Infos

The papers in this book deal with computational methods for predicting material processing defects. Using recent advances in finite strain plasticity and viscoplasticity, damage modelling, bifurcation and instability theory, fracture mechanics and computer numerical techniques, new approaches to mechanical defect analysis are proposed. Appropriate methods for explaining and avoiding the defects leading to fracture, high porosity, strain localization or undesirable geometrical imperfections are presented. In addition, some papers are devoted to new formulations and new calculation algorithms to be used for solving the forming problems. Finally, two papers deal with physical description of defects occurring in forming and cutting operations, focusing on the academic and practical interest of these topics.This is the first book to deal with the prediction of defects occurring in material forming processes; it contains much of interest from both a theoretical and a practical viewpoint.

Inhalt

Front Cover 1
Computational Methods for Predicting Material Processing Defects 4
Copyright Page 5
Table of Contents 8
PREFACE 6
CHAPTER 1. NUMERICAL SIMULATIONS OF DYNAMICAL METAL FORMING 10
SUMMARY 10
NOTATIONS 10
PRINCIPLES OF THE SYSTEM 10
APPLICATIONS 15
REFERENCES 17
CHAPTER 2. NUMERICAL COMPUTING TECHNIQUE FOR PREDICTING THICKNESS CHANGING IN DEEPDRAWING OF AUTOBODY SHEET 18
SUMMARY 18
INTRODUCTION 18
BASIC THEORY 18
RESULTS 25
CONCLUSION 27
REFERENCES 27
CHAPTER 3. AN EULERIAN FINITE ELEMENT METHOD FOR THE THERMAL AND VISCO PLASTIC DEFORMATIONOF METALS IN INDUSTRIAL HOT ROLLING 28
SUMMARY 28
INTRODUCTION 28
THERMAL PROBLEM 29
FINITE ELEMENT FORMULATIONS 30
RESULTS AND DISCUSSION 31
CONCLUSIONS 32
REFERENCES 33
CHAPTER 4. SURFACE DEFECTS IN HOT ROLLING OF COPPER BASED ALLOYS HEAVY INGOTS: THREE DIMENSIONAL SIMULATION INCLUDING FAILURE CRITERION 38
SUMMARY 38
INTRODUCTION 38
PRESENTATION OF THREE DIMENSIONAL ROLLING PROGRAM 38
APPLICATION TO COPPER BASED INGOTS 40
DISCUSSION OF FAILURE RISK PREDICTION 42
CONCLUSION 47
REFERENCES 47
CHAPTER 5. ANALYSIS OF THE PROFILE OF LOCAL NECKING IN SHEET METAL DEFORMATIONPROCESSES 48
SUMMARY 48
INTRODUCTION 48
THEORETICAL ANALYSIS 49
RESULTS AND DISCUSSION 51
ACKNOWLEDGEMENTS 52
REFERENCES 55
CHAPTER 6. A FINITE ELEMENT ANALYSIS OF SPRINGBACK IN PLANE STRAIN FOLDING WITH BINDERS OFHIGH STRENGTH STEEL SHEETS 56
SUMMARY 56
INTRODUCTION 56
GOVERNING EQUATIONS 57
BOUNDARY CONDITIONS 58
FINITE ELEMENT APPROXIMATION 59
SOLUTION PROCEDURE 60
NUMERICAL RESULTS 61
CONCLUSION 64
REFERENCES 64
CHAPTER 7. PREVISION DES DEFAUTS DE GEOMETRIE AU COURS DU LAMINAGE A CHAUD DES ACIERS 66
RESUME 66
INTRODUCTION 66
LOI CONSTITUTIVE DES ACIERS DE LAMINAGE 66
MODELISATION DU SOLIDE 67
MODELISATION DU CONTACT 72
DEFAUTS DE GEOMETRIE AU COURS DU LAMINAGE 73
REFERENCES 74
CHAPTER 8. INFLUENCE OF STRAIN GRADIENTS IN SHEET METAL FORMING 78
1. INTRODUCTION 78
2. NECKING CRITERIA 78
3. INFLUENCE OF STRAIN GRADIENTS 80
4. EXPERIMENTAL STUDY 81
5. CONCLUSION 82
REFERENCES 82
CHAPTER 9. SURFACE DEFECTS AND FAILURE OF ADHESION IN POLYMER MELT EXTRUSION 86
SUMMARY 86
INTRODUCTION 86
NUMERICAL COMPUTATION 88
CONCLUSION 88
ACKNOWLEDGMENTS 89
REFERENCES 89
CHAPTER 10. LARGE STRAIN FORMULATION OF ANISOTROPIC ELASTO-PLASTICITY FOR METAL FORMING 90
SUMMARY 90
1. INTRODUCTION 90
2. THE ISOTROPIC CASE 91
3. ANISOTROPIC RIGID PLASTICITY 94
4. ANISOTROPIC ELASTO-PLASTICITY 98
5. CONCLUSION 100
REFERENCES 100
CHAPTER 11. DRAWING OF VISCOPLASTIC TUBES THROUGH ROTATING CONICAL DIES 102
SUMMARY 102
1. INTRODUCTION 102
2. FORMULATION OF THE PROBLEM 104
3. SOLUTIONS FOR THE NEWTONIAN FLUID 106
4. APPROXIMATE SOLUTION FOR THE POWER LAW VISCOUS SOLID 107
ACKNOWLEDGEMENT 111
REFERENCES 111
CHAPTER 12. INFLUENCE OF THE BLANK CONTOUR ON THE THICKNESS VARIATION IN SHEET METAL FORMING 112
SUMMARY 112
INTRODUCTION 112
FINITE ELEMENT FORMULATION 113
NUMERICAL APPLICATIONS 116
REFERENCES 118
CHAPTER 13. CHARACTERIZATION AND MODELING OF SPREAD IN ROLLING ANISOTROPICSTRIP 122
SUMMARY 122
NOMENCLATURE 122
NOMENCLATURE 122
INTRODUCTION 122
EXPERIMENTAL 123
RESULTS AND DISCUSSION 124
DEVELOPMENT OF SPREAD MODEL 128
CONCLUSIONS 129
ACKNOWLEDGEMENTS 129
REFERENCES 129
CHAPTER 14. NUMERICAL ANALYSES OF STRAIN RATE AND TEMPERATURE EFFECTS ON LOCALIZATION OFPLASTIC FLOW AND DUCTILE FRACTURE - APPLICATIONS TO METAL FORMING PROCESSES 132
ABSTRACT 132
INTRODUCTION 132
CONSTITUTIVE EQUATIONS 133
ANALYSIS OF PLASTIC FLOW LOCALIZATION 136
REFERENCES 141
CHAPTER 15. SOME PHYSICAL DEFECTS ARISING IN LASER, PLASMA AND WATER JET CUTTING 142
SUMMARY 142
INTRODUCTION 142
LASER PROCESSING 143
PLASMA PROCESSING 148
WATER JET CUTTING 151
CONCLUSIONS 155
REFERENCES 155
CHAPTER 16. THEORETICAL PREDICTION OF THE LIMIT CURVES FOR SIMULATION OFPLASTIC INSTABILITY 170
SUMMARY 170
INTRODUCTION 170
THEORETICAL ANALYSIS OF THE FORMING LIMIT DIAGRAMS 171
EXPERIMENTAL METHODS AND MATERIALS 173
RESULTS AND DISCUSSION 175
CONCLUSIONS 178
ACKNOWLEDGEMENTS 179
REFERENCES 179
CHAPTER 17. HOMOGENIZATION OF A PLASTIC POROUS MEDIA. INFLUENCE OF SECONDARYCAVITIES 180
SUMMARY 180
INTRODUCTION 180
STATEMENT OF THE PROBLEM 181
NUMERICAL RESULTS 183
DISCUSSION 186
REFERENCES 188
CHAPTER 18. A NOTE ON ADIABATIC FLOW LOCALIZATION IN VISCOPLASTIC SOLIDS 190
SUMMARY 190
INTRODUCTION 190
LOCALIZATION CRITERION 192
NUMERICAL EXAMPLE 194
DISCUSSION AND CONCLUSIONS 196
ACKNOWLEDGEMENTS. 197
REFERENCES 197
CHAPTER 19. A COMPUTATIONAL METHOD TO ESTIMATE THE FORMABILITY OF COLD FORGING STEELS 202
SUMMARY 202
INTRODUCTION 202
EXPERIMENTAL MATERIALS AND PROCEDURES 203
DISCUSSION 209
CONCLUSIONS 210
REFERENCES 210
CHAPTER 20. STRESSES AND DISLOCATION DENSITY DURING GROWTH OF SINGLE III-VSEMICONDUCTOR CRYSTALS FROM THE MELT 212
SUMMARY 212
INTRODUCTION 212
TEMPERATURE DISTRIBUTION 213
RESULTS 218
DISCUSSION 221
REFERENCES 221
CHAPTER 21. NUMERICAL ANALYSIS OF THE INFLUENCE OF VARIOUS DEFECTS ON SUPERPLASTIC FRACTUREUNDER UNIAXIAL TENSION 222
SUMMARY 222
I. INTRODUCTION 222
II. ANALYSIS 223
Ill RESULTS AND DISCUSSION 225
IV CONCLUSION 229
REFERENCES 229
CHAPTER 22. Finite Element Simulation of Bending Process of Steel-Plastic Laminate Sheets 230
SUMMARY 230
INTRODUCTION 230
FINITE ELEMENT MODELING 232
EXPERIMENT 235
RESULTS 236
CONCLUSIONS 237
ACKNOWLEDGEMENT 238
REFERENCES 238
CHAPTER 23. DEFECTS IN THE PROCESSING OF METALS AND COMPOSITES 240
SUMMARY 240
INTRODUCTION 240
PROCESSING OF COMPOSITE MATERIALS 254
CONCLUDING REMARKS 257
ACKNOWLEDGEMENTS 258
REFERENCES 258
CHAPTER 24. Damage Evolution Modeling in Bulk Forming Processes 260
Abstract 260
Notation 260
Introduction 260
A Metal Forming Model with Damage 261
Numerical Solution of the Model Equations 264
Application to Strip Drawing 266
Effect of Geometry Changes on Material Damage 268
Conclusions 268
Acknowledgements 268
REFERENCES 269
CHAPTER 25. PREDICTION OF THE WRINKLING INSTABILITIES BY LONG WAVELENGTH PERTURBATIONS INTHIN SHEET METAL FORMING 272
SUMMARY 272
INTRODUCTION 272
EQUATIONS OF EQUILIBRIUM 275
CRITERION OF STABILITY IN CASE OF WRINKLING PERTURBATIONS 278
APPLICATIONS OF THE STABILITY CRITERION 282
REFERENCES 283
CHAPTER 26. CRITICAL DAMAGE AND DUCTILE FRACTURE : QUANTITATIVE EXPERIMENTAL DETERMINATION 284
SUMMARY 284
INTRODUCTION 284
MECHANICAL AND PHYSICAL DESCRIPTION OF FRACTURE PROCESSES 285
EXPERIMENTAL PROCEDURE 289
RESULTS AND DISCUSSION 291
CONCLUSIONS 296
ACKNOWLEDGEMENTS 297
REFERENCES 297
CHAPTER 27. METHOD OF CALCULATION OF CURVE OF DEFORMABILITY OF K18 STEEL 298
SUMMARY 298
CURVE OF DEFORMABILITY 298
EXPERIMENTAL RESULTS 300
CONCLUSIONS 301
REFERENCES 302
CHAPTER 28. FINITE STRAIN PLASTICITY ANALYSIS OF DAMAGE EFFECTS IN METALFORMING PROCESSES 304
Summary 304
INTRODUCTION 304
MODELLING OF DAMAGE EFFECTS 306
CONSTITUTIVE BRANCHING 311
APPLICATIONS 312
REFERENCES 313
CHAPTER 29. PLASTIC INSTABILITY OF PRESTRAINED MATERIALS 318
SUMMARY 318
INTRODUCTION 318
FORMING LIMIT DIAGRAMS 319
MICROSTRUCTURAL APPROACH OF PLASTIC BEHAVIOR OF PRESTRAINED METALS 322
CONCLUSION 326
ACKNOWLEDGEMENTS 326
REFERENCES 326
CHAPTER 30. TAKING INTO ACCOUNT THE FORGING PROCESS IN COMPUTER AIDED DESIGN TO INCREASETHE LIFE OF THE DIES 328
ABSTRACT 328
INTRODUCTION 328
OPTIMIZED FORGING DESIGN FEATURES 328
GIVING A COST FOR A PART 335
REFERENCES 338
CHAPTER 31. DAMAGE ARREST BY CLOSURE OF VOIDS IN DILATANT SOLIDS SUBJECTED TO COMPRESSIVELOAD 340
SUMMARY 340
INTRODUCTION 340
CONSTITUTIVE EQUATION 341
RESULTS AND DISCUSSION 344
REFERENCES 345
CHAPTER 32. TEMPERATURE DISTRIBUTION IN STRIP ROLLING OF RATE SENSITIVE MATERIAL 352
SUMMARY 352
INTRODUCTION 352
MATHEMATICAL ANALYSIS 353
CONCLUDING REMARKS 354
REFERENCES 355
CHAPTER 33. DAMAGE DURING FORMING OF COATED SHEET STEEL 356
SUMMARY 356
INTRODUCTION 356
RESULTS AND DISCUSSION 357
CONCLUSION 364
REFERENCES 365
CHAPTER 34. DEFECTS AT INTERFACES IN CO-EXTRUDED METALS 366
SUMMARY 366
INTRODUCTION 366
THEORETICAL BACKGROUND 367
INTERFACIAL STRENGTH EVALUATION 368
EXPERIMENTAL PROCEDURES 369
INTERFACIAL STRENGTH MEASUREMENTS 371
FINITE ELEMENT SIMULATION 372
DISCUSSION AND CONCLUSIONS 374
ACKNOWLEDGMENTS 375
REFERENCES 375

Produkt-Details

• Erscheint lt. Verlag: 28.6.2014
• Sprache: englisch
• Themenwelt: Mathematik / Informatik ► Informatik ► Theorie / Studium
• Themenwelt: Technik ► Bauwesen
• Themenwelt: Technik ► Maschinenbau
• Themenwelt: Wirtschaft
• ISBN-10: 1-4832-9849-3 / 1483298493
• ISBN-13: 978-1-4832-9849-8 / 9781483298498