Electrically Assisted Forming – Modeling and Control

Electrically Assisted Forming – Modeling and Control
اسم المؤلف
Wesley A. Salandro , Joshua J. Jones , Cristina Bunget , Laine Mears , John T. Roth
التاريخ
25 مارس 2023
المشاهدات
193
التقييم
(لا توجد تقييمات)
Loading...

Electrically Assisted Forming – Modeling and Control
Wesley A. Salandro , Joshua J. Jones , Cristina Bunget , Laine Mears , John T. Roth
Contents
1 Deformation of Metals 1
1.1 Relevant Background on Automotive and Aerospace Industries . 2
1.2 Present Forming Technologies . 4
1.2.1 Hot Working . 5
1.2.2 Incremental Forming 5
1.2.3 Superplastic Forming 6
1.2.4 Tailor-Welded Blanking 7
1.3 Limitations of Current Technologies 8
1.4 Plastic Deformation of Metals . 8
1.4.1 Bonding 9
1.4.2 Dislocations . 10
1.4.3 Crystalline Structures 13
1.4.4 Lattice Defects . 14
1.5 Metrics of Formability . 17
1.5.1 Formability in Sheet Metals . 17
1.5.2 Additional Forming Metrics . 18
1.6 Conclusions . 20
References . 20
2 Introduction to Electrically Assisted Forming . 23
2.1 Electrically Assisted Forming . 23
2.2 EAF Literature Review . 25
2.2.1 EAF Theory and Modeling 26
2.2.2 Significant EAF Modeling Variables
from Experimentation 28
2.2.3 Relation to Crystal Structure and Resistivity 32
2.2.4 Electroplasticity and Electromigration . 33
2.3 Broader Impacts of EAF 33
2.3.1 Automotive and Aerospace Industries . 33
2.3.2 Potential Early Adopters of EAF Modeling . 34
References . 34x Contents
3 The Effect of Electric Current on Metals . 37
3.1 Electrical Current Flow 37
3.2 Previous Electroplastic Theories . 39
3.2.1 Localized Heating . 39
3.2.2 Electron Wind Effect 42
3.3 Comprehensive Electroplastic Theory Explanation . 43
3.3.1 Electrical Current Without Metal Deformation 43
3.3.2 Electrical Current with Metal Deformation . 46
3.3.3 Electrical Current Effects on Formability 48
3.3.4 Supporting Experimental Results . 49
3.4 Electroplastic Theory Conclusions 51
References . 53
4 Macroscale Modeling of the Electroplastic Effect 55
4.1 Mechanical-Based Approach to Determining the EEC 55
4.1.1 Experimental Setup and Procedure . 56
4.1.2 Mechanical-Based EEC Determination Procedure . 57
4.1.3 Mechanical-Based EEC Conclusions 58
4.2 Thermal-Based Approach to Determining the EEC . 58
4.2.1 Building a Thermal Model 59
4.2.2 Experimental Setup and Procedure . 63
4.2.3 EEC Thermal-Based Determination . 65
4.2.4 Thermal-Based EEC Conclusions 70
4.3 Comparison Between the Different EEC Determination
Approaches 71
4.3.1 SS304 Electroplastic Effect Coefficient Profiles . 71
4.4 EEC Profile Conclusions . 72
4.5 Empirical Modeling Strategies . 73
4.5.1 Non-constant Current Density . 73
4.5.2 Constant Current Density . 78
4.6 Macroscale Modeling of the Electroplastic Effect Conclusions . 82
References . 82
5 Compressive Electrically Assisted Forming Model . 83
5.1 Analytical Modeling of Compression Forming Processes 83
5.1.1 Definition of an EAF Modeling Strategy . 83
5.1.2 Analysis of an Electrically Assisted
Compression Process 84
5.1.3 Effective Stress and Strain—Classical
Compression Test . 85
5.1.4 Effective Stress and Strain—Electrically
Assisted Compression Test 86
5.1.5 Current Density Relationship During
Electrically Assisted Compression 88Contents xi
5.1.6 Strain and Temperature Effect on Resistance
and Current 89
5.1.7 Analytical Model for Electrically Assisted
Compression . 89
5.1.8 Overall Solution Schematic . 90
5.1.9 EAF Modeling Approach Summary . 91
5.2 Simplified EAF Forging Model 91
5.2.1 EAF Forging Stress–Strain Model 91
5.2.2 Modeling Strategy Overview 92
5.2.3 Coupled Thermo-Mechanical Modeling . 92
5.2.4 Assumptions of the Thermo-Mechanical Model . 94
5.2.5 Experimental Setup and Procedure . 96
5.2.6 Experimental and Modeling Results 97
5.2.7 Electrical Efficiency Analysis . 100
5.2.8 EAF Forging Model Conclusions . 101
5.3 Specific Heat Sensitivity . 102
5.4 Heat Transfer Modes Analysis . 104
5.5 EEC Profile—Material Sensitivity Comparison 107
5.6 EAF Modeling—Sensitivities and Simplifications
Conclusions . 109
References . 110
6 Tensile Electroforming Model 113
6.1 Thermal Modeling 113
6.1.1 Model Development . 114
6.1.2 Experimental Setup . 123
6.1.3 Results and Discussion . 124
6.1.4 Thermal Model Conclusions 132
6.2 Mechanical Modeling 133
6.2.1 Deformation/Strength Model Derivation . 134
6.2.2 Deformation/Strength Model Solution Method 137
6.2.3 Deformation/Strength Model Results 140
6.2.4 Mechanical Modeling Conclusions . 152
6.3 Thermo-Mechanical Model . 153
6.3.1 Thermo-Mechanical EAF Model Overview
and Solution Scheme 153
6.3.2 Thermal Expansion Stress 154
6.3.3 Model Results 155
6.3.4 Division of Thermal Expansion, Thermal
Softening, and Direct Electrical Effects 157
6.3.5 Thermo-Mechanical Modeling Conclusions 158
6.4 Tensile Electroforming Model Conclusions . 159
References . 159xii Contents
7 Control of Electrically Assisted Forming . 161
7.1 Constant Force Forming 162
7.1.1 Benefits of Constant Force Forming . 168
7.2 Constant Stress Forming . 169
7.2.1 Benefits and Opportunities of Constant
Stress Forming . 171
7.3 Constant Current Density Forming . 172
7.3.1 Benefits of Constant Current Density Forming 174
7.4 Model-Based Control Feasibility . 175
7.5 Process Control Conclusions 176
References . 177
8 Microstructure and Phase Effects on EAF 179
8.1 Grain Size Effect on EAF . 179
8.1.1 Specimen Preparation and Resulting Grain Sizes 180
8.1.2 Experimental Grain Size Testing . 181
8.1.3 EAF/Grain Size Conclusions 183
8.2 Prior Cold Work Effect on EAF 183
8.2.1 Importance of Percent Cold Work
on EAF Effectiveness 184
8.2.2 Specimen Preparation 184
8.2.3 Experimental Setup and Procedure . 185
8.2.4 Results and Discussion . 186
8.2.5 EAF/Percent Cold Work Conclusions . 191
8.3 Microstructure Analysis Under Tensile Loading . 192
8.3.1 As-Received Material Microstructure . 192
8.3.2 Summary of Statistical Analysis of Micrographs . 195
8.3.3 Room Temperature Deformation Microstructure . 198
8.3.4 EAF Microstructure . 201
8.3.5 Microstructure Analysis Conclusions 209
References . 210
9 Tribological and Contact Area Effects . 211
9.1 Contact Area Effect on EAF Effectiveness . 211
9.1.1 Specimen Preparation (Surface Ground) . 212
9.1.2 Specimen Preparation (Enhanced Asperities) . 212
9.1.3 Post-forming EAF Roughness Examination 214
9.1.4 Experimental Setup and Procedure . 216
9.1.5 Thermal Analysis of EAF Based on Contact Area 217
9.1.6 Voltage–Resistance Contact Area Model . 223
9.1.7 Mechanical Analysis of EAF Based
on Contact Area 226
9.1.8 EAF/Contact Area Conclusions 230Contents xiii
9.2 Tribological Effect on EAF Effectiveness 231
9.2.1 Effects of Electricity on Tribological Conditions . 232
9.2.2 Experimental Setup and Procedure
(Ring Tribo-Tests) 233
9.2.3 Determining Friction Calibration Curves . 235
9.2.4 Testing Procedures 235
9.2.5 Candidate Metal Forming Lubricants 237
9.2.6 Experimental Results and Discussion . 238
9.2.7 Lubricant Evaluation (Reduction
in Forming Load) . 238
9.2.8 Temperature Measurements . 241
9.2.9 EAF/Tribology Conclusions . 243
References . 243
10 Design of an Electrically Assisted Manufacturing Process . 245
10.1 Energy Analysis 245
10.1.1 Conventional Cold Forming . 245
10.1.2 Thermally Assisted Forming 247
10.1.3 Electrically Assisted Forming . 249
10.1.4 Energy Comparison . 250
10.2 AC Versus DC Current . 251
10.2.1 Energy Analysis 251
10.2.2 Skin Effect 251
10.3 Additional Process Design Considerations . 252
10.3.1 Power Supply 252
10.4 EAF Process Design Conclusions 253
11 Applications of Electrically Assisted Manufacturing 255
11.1 EAF Bending Application and Model . 255
11.1.1 Analysis of an EA Bending Process . 257
11.1.2 Assumptions of the EAB Model . 257
11.1.3 Classical Bending Process (Force and Springback) . 258
11.1.4 Analytical Modeling of EAB 260
11.1.5 EAB Solution Schematic . 263
11.1.6 Experimental Setup and Procedure . 264
11.1.7 Thermal Measurements in EAB 268
11.1.8 Validation of the Model via Experiments . 269
11.1.9 Effects of Electricity in Bending . 270
11.1.10 EAB Model Conclusions . 276
11.2 Electrically Assisted Machining 277
11.2.1 Observations in Low-Strain-Rate EA Machining 277
11.2.2 High-Strain-Rate Process Modeling
and Experimental Testing for EA Machining 279
11.2.3 EA Machining Conclusions . 283xiv Contents
11.3 Electrically Assisted Friction Stir Welding . 284
11.3.1 Electrically Assisted Friction Stir
Welding Background 284
11.3.2 EAFSW Experimental Setup 285
11.3.3 Results and Discussion . 287
11.3.4 Conclusions and Future Work . 291
11.4 Experimental Findings for Alternative EAF Processes 291
11.4.1 Compression . 292
11.4.2 Tension . 294
11.4.3 Non-uniform Deformation
(E.G. Channel Formation) 300
11.4.4 Springback Reduction Using EAF 301
11.4.5 Electrically Assisted Micro-Forming 302
11.5 Overhead Transmission Line Design Using EAF 303
11.5.1 The Electricity Transmission Grid 303
11.5.2 Transmission Line Structures and Setups . 303
11.5.3 Commercial Conductors and Sizing . 304
11.5.4 Conductor Sag . 305
11.5.5 Effect of Temperature on Transmission
Line Longevity . 306
11.5.6 Applying EAF Modeling to OHTL
Sag Calculations 307
11.5.7 Future Work to Determine EEC Values
for OHTL’s 309
References . 309
Appendix A . 313
Appendix B . 327
Abbreviations
AISI American Iron and Steel Institute
AO Analog Output
APF Atomic Packing Factor
ASTM American Society for Testing and Materials
BCC Body-Centered Cubic
CAE Computer-Aided Engineering
CAFE Corporate Average Fuel Economy
CCD Constant Current Density
CGA Circle Grid Analysis
CI Confidence Interval
cRIO CompactRIO
DOT Department of Transportation
EA Electrically Assisted
EAF Electrically Assisted Forming
EA-Forging Electrically Assisted Forging
EAM Electrically Assisted Manufacturing
EDM Electrical Discharge Machining
EEC Electroplastic Effect Coefficient
EPA Environmental Protection Agency
FCC Face-Centered Cubic
FE Finite Element
FEA Finite Element Analysis
FFT Fast Fourier Transform
FLC Forming Limit Curve
FLD Forming Limit Diagram
FLIR Forward-Looking Infrared
GBS Grain Boundary Sliding
GHG Greenhouse Gas
GUI Graphical User Interface
HCP Hexagonal Close Packed
IF Incremental Formingxvi Abbreviations
LDH Limiting Dome Height
LVDT Linear Variable Differential Transformer
MBC Model-Based Control
NCCD Non-Constant Current Density
NI National Instruments
OEM Original Equipment Manufacturer
PID Proportional-Integral-Derivative
PLC Portevin–Le Chatelier
PS Parameter Set
SCR Silicon Controlled Rectifier
SMDI Steel Market Development Institute
SPF Superplastic Forming
TWB Tailor Welded Blank
UHSS Ultra-High Strength Steel

كلمة سر فك الضغط : books-world.net
The Unzip Password : books-world.net

تحميل

يجب عليك التسجيل في الموقع لكي تتمكن من التحميل
تسجيل | تسجيل الدخول

التعليقات

اترك تعليقاً