Thermal Effects in Complex Machining Processes (eBook)

Contents 6
Introduction 8
Part I Collaboration within the Working Groups 10
2 Temperature Measurements and Heat Partitioning in Machining Processes 11
Abstract 11
1 Introduction 11
2 Objectives 12
3 Temperature Measurement Techniques 13
3.1 Contacting Thermometers 13
3.1.1 Resistance Thermometers 13
3.1.2 Thermocouples 13
3.2 Radiation Thermometers 14
3.2.1 Radiation Detectors 15
3.2.2 Types of Radiation Thermometers 16
4 Calibration of Thermometers in the Priority Programme 16
4.1 Contacting Thermometers 16
4.1.1 Resistance Thermometers 17
4.1.2 Thermocouples 18
4.1.3 Calibration Procedure 18
4.2 Radiation Thermometers 19
4.2.1 Calibration Setup 19
4.2.2 Calibration Procedure 20
5 Temperature Measurement Setups and Heat Partitioning 21
5.1 Selected Temperature Measurements Setups 21
5.1.1 Thermocouples 21
5.1.2 Infrared Cameras 23
5.2 Heat Partition to the Workpiece 24
6 Summary and Conclusions 26
Acknowledgements 27
References 27
Optimization and Compensation Strategies 28
1 Introduction 28
2 Optimization Strategies 29
3 Compensation Strategies 30
References 31
4 Material Modelling 33
Abstract 33
1 Introduction 33
2 Material Laws 34
3 Friction 34
4 Phase Transformations 35
Acknowledgements 36
References 36
Part II Final Reports of the Research Projects 37
Improvement of the Machining Accuracy in Dry Turning of Aluminum Metal Matrix Composites via Experiments and Finite Element Simulations 38
1 Introduction 39
2 Experimental Investigations 39
3 Finite Element Modeling 43
3.1 Local Model of Chip Formation 44
3.2 Global Model of the Workpiece 47
3.3 Global Model of the Tool 51
4 Approach for the Compensation of the Workpiece and Tool Deformation 53
5 Validation of the FE Models 54
5.1 Local Model 54
5.2 Global Models 55
6 Thermal Load of the Workpiece 57
7 Machining Accuracy and Surface Integrity 58
8 Results of the Compensation of the Workpiece and Tool Deformation 60
9 Conclusion 62
References 63
Modelling and Compensation of Thermoelastic Workpiece Deformation in Dry Cutting 66
1 Introduction 66
2 Fundamental Investigations 67
2.1 In-situ Recording of Chip Formation in Orthogonal Cutting 68
2.2 Friction Experiment Under Cutting Conditions 69
2.3 Shear Zone Contact Conductance Model 73
3 Modelling and Compensation of Thermoelastic Workpiece Deformation in Dry Turning 77
3.1 Mesoscopic FE-Modelling 77
3.2 Heat Flux into the Workpiece During Orthogonal Turning 81
3.3 Comparison of the Heat Flux Between IHCP and Mesoscopic FE-Model 86
3.4 Minimization of Workpiece Warming 87
3.5 Macroscopic FE-Modelling for Thermoelastic Workpiece Deformation 90
4 Conclusion and Future Work 95
References 96
Thermo-Mechanical Simulation of Hard Turning with Macroscopic Models 98
1 Introduction 98
2 Test Conditions and Measurement Methods 100
2.1 Cutting Experiments 100
2.2 Thermal Experiments 101
3 Experimental Results 103
3.1 Cutting Forces 103
3.2 Workpiece Surface Temperature 104
3.3 Heat-Up and Cooling Rates 105
4 A Multi-mechanism Model for Cutting Simulations 105
4.1 A Thermodynamic Framework for Visco-Plasticity and Phase Transformations Based on the Concept of Generalized Stresses 107
4.2 A Prototype Model for Hard Turning Simulation 110
5 Parameter Identification 114
5.1 Mechanical Tests for Visco-Plasticity and Hardness Dependency 114
5.2 Dilatometer Tests for TRIP-strains 118
6 Cutting Simulations in ABAQUS for Testing the Model 121
7 Simulation in Deform 126
7.1 Modelling in Deform 126
7.2 Influence of the Cutting Edge Geometry on the Thermo-Mechanical Work Piece Load 127
7.3 Impact of Dissimilar Stress States on Work Piece Heat Balance 127
7.4 Method for Analysis of the Influence of Physical Phenomena on the Workpiece Stress Distribution During Hard Turning 129
8 Model-Based Optimization of the Hard Turning Process 129
8.1 Process Parameters 129
8.2 Machining Strategies 131
9 Summary and Outlook 132
References 133
8 Modeling of Orthogonal Metal Cutting Using Adaptive Smoothed Particle Hydrodynamics 136
Abstract 136
1 Introduction 136
2 Smoothed Particle Hydrodynamics for Solid Continua 137
2.1 Basic Equations of Continuum Mechanics 137
2.2 Plasticity and Fracture Behavior 138
2.3 Boundary Contact Force 139
2.4 Variable Smoothing Length 139
2.5 Local Adaptive Particle Refinement 140
3 Orthogonal Metal Cutting Simulation 141
3.1 Model Setup 141
3.2 Results 142
4 Conclusion 145
References 145
9 Experimental and Simulative Modeling of Drilling Processes for the Compensation of Thermal Effects 147
Abstract 147
1 Introduction 148
2 Experimental Investigations 148
2.1 Orthogonal Turning Experiments 148
2.2 Drilling Experiments 152
2.3 Investigation of Friction 156
2.4 Metallurgical Investigations 160
3 Simulation Models 160
3.1 2D Chip Formation Simulation 160
3.1.1 Material Model 161
3.1.2 Friction Modeling 161
3.1.3 Phase Transformations 162
3.1.4 Minimum Quantity Lubrication 163
3.2 3D Drilling Simulation 165
3.2.1 Simplified Drilling Model 166
3.2.2 Modeling of Thermal and Mechanical Loads 167
3.2.3 Modeling Phase Transformations 168
3.2.4 Modeling Minimum Quantity Lubrication 168
3.3 Advanced Drilling Model 170
3.3.1 Modeling of Thermal and Mechanical Loads 170
3.3.2 Modeling Efficiency 171
3.3.3 Compensation Strategies for Thermal Effects 174
Optimization of Machining Strategies 174
Thermal Management 176
3D Circular Milling 178
Acknowledgements 181
References 181
Modelling, Simulation and Compensation of Thermomechanically Induced Deviations in Deep-Hole Drilling with Minimum Quantity Lubrication 183
1 Introduction 184
2 Technological Investigations 185
2.1 Experimental Conditions 185
2.2 Thermomechanical Workpiece Load 187
2.3 Workpiece Distortion and Deviations 191
2.4 High-Performance Deep-Hole Drilling 194
3 Microscopic Modelling and Simulation 197
3.1 Thermoplastic Model with Frictional Contact 198
3.2 Chip Formation 199
3.3 Discretising Elasto-Plastic Contact Problems Efficiently 200
3.4 Solving Elasto-Plastic Contact Problems Efficiently 200
4 Macroscopic Modelling and Simulation 201
4.1 Thermoelastic Model with Secondary Heat Source 202
4.2 Fictitious Domain Approach 203
4.3 A Residual Error Estimator 206
4.4 Further Studies 210
5 Simulation and Compensation of Thermomechanically Induced Deviations 211
5.1 Compensation Procedure 213
6 Conclusions 217
References 218
Thermomechanical Deformation of Complex Workpieces in Milling and Drilling Processes 221
1 Introduction 222
2 Experimental Investigation 223
2.1 Mechanical Load 224
2.2 Thermal Load 224
2.3 Thermal Balancing 226
3 Process Model 227
3.1 Geometric Tool Modeling 228
3.2 Contact-Zone Analysis 229
3.3 The Force Model 231
3.4 Empirical Model for the Heat Induced by the Process 234
3.5 Workpiece Load 234
4 Workpiece Model 236
4.1 Thermomechanical Extended Dexel-Model 236
4.2 Thermomechanical Finite Element Model 237
4.3 Linking of Dexel and FE Models 238
4.4 Shape Deviation Prediction 240
5 Optimization 241
5.1 Optimal Roughing 243
5.2 NC Path Optimization 244
5.3 Tool Path Optimization by Tool Axis Adaption 246
5.4 Target Workpiece Comparison 247
5.5 Reference Processes 248
5.6 Analysis and Axis Adaption of the Reference Processes 248
6 Conclusion and Discussion 251
References 252
12 Compensation Strategies for Thermal Effects in Dry Milling 253
Abstract 253
1 Introduction 256
2 Objectives, Procedure and Working Programme 257
2.1 Objectives 257
2.2 Procedure 258
2.2.1 Hybrid Model and Optimisation Procedure 258
2.2.2 Simultaneous Analysis and Design 260
2.3 Working Programme and Tool Data 261
3 Modelling Workpiece Shape Deviations Caused by Milling Induced Source Stresses 262
3.1 Analytical Model for the Calculation of Source Stresses 262
3.2 Multilayer Model for Source Stresses 262
3.3 Determination of Source Stresses 264
3.3.1 Experimental Programme 265
3.3.2 Source Stress Regression Model 266
3.4 Finite Element Formulation of the Source Stress Model 267
3.4.1 Derivation of the Mathematical Model 267
3.4.2 Model Verification 268
4 Modelling Workpiece Shape Deviations Caused by Thermo-Elastic Strains 269
4.1 Determination of Heat Flux Densities 269
4.1.1 Experimental Programme 270
4.1.2 Finite Element Model 270
4.1.3 Identification of Heat Flux Densities 270
4.1.4 Thermo-Elastic Regression Model 271
4.2 Modelling Workpiece Shape Deviations Caused by Thermo-Elastic Strains 271
4.3 Model Reductions for the Thermo-Elastic Simulations 273
5 Optimisation of Milling Strategies 273
5.1 Distinction Between Discrete and Continuous Variables 273
5.2 Minimisation of Shape Deviations Caused by Source Stresses—Optimisation Step 1 274
5.2.1 Investigation of Discrete Variables—Milling Strategies 274
5.2.2 Mathematical Formulation of the Optimisation of Continuous Variables 275
5.2.3 Numerical Optimisation Results and Discussion 276
5.3 Minimisation of Total Shape Deviations—Optimisation Step 2 280
5.3.1 Mathematical Formulation 280
5.3.2 Numerical Optimisation Results and Discussion 281
6 Validation of the Optimised Milling Strategies 282
6.1 Procedure 282
6.2 Results 283
6.2.1 Machining of Stress Relief Annealed Workpieces 283
6.2.2 Machining of Workpieces Containing Residual Stress 285
7 Summary and Conclusions 287
7.1 Hybrid Model 287
7.2 Optimisation of Milling Strategies 287
7.3 Validation 288
Acknowledgements 289
References 289
Modeling, Simulation and Compensation of Thermomechanically Induced Material Deformation in Dry NC Milling Processes 291
1 Introduction 292
2 Related Work 293
3 Modeling of Workpiece Deformations in Milling Processes 296
3.1 Finite Element Method 296
3.2 GP Process Simulation 302
3.3 GP-FEM Linkage 308
3.4 FEM Update Intervals 310
4 Validation of the Simulation Approach 311
4.1 Experimental Setup 311
4.2 Simulation of the Experiment 313
4.3 Results 314
5 Compensation of Thermomechanical Workpiece Deformations 317
5.1 Deformation of the NC Milling Path 317
5.2 Validation of the Deformed Milling Path 318
6 Summary and Outlook 319
References 320
14 Coupling Analytical and Numerical Models to Simulate Thermomechanical Interaction During the Milling Process of Thin-Walled Workpieces 323
Abstract 323
1 Motivation 324
2 Objective and Approach 325
3 Project Results 331
4 Conclusion 345
Acknowledgements 347
References 347
15 Modeling, Simulation and Compensation of Thermal Effects in Gear Hobbing 349
Abstract 349
1 Introduction 349
2 Hobbing of Large Ring Gears 350
3 Temperature Measurement 352
4 Temperature Measurement in Industry 357
5 Simulation Setup 360
6 Simulation Backgrounds—Dexel 361
7 Simulation Backgrounds—Kinematic 361
8 Simulation Backgrounds—FE-Dexel Coupling 363
9 FE-Dexel Coupling: Remarks/Benefits 364
10 Simulation Results 365
11 Conclusion 367
Acknowledgements 368
References 368
Modelling and Simulation of Internal Traverse Grinding---From Micro-thermo-mechanical Mechanisms to Process Models 370
1 Introduction 371
1.1 Simulation Framework 371
2 Experiments and Thermo-Mechanical Loading During ITG 372
3 Geometric-Kinematic Simulation 379
4 Finite Element Modelling of ITG 381
4.1 Single Grain Finite Element Model 381
4.2 Bridging Approach 387
5 Process Model and Compensation Strategies 394
5.1 Compensation Strategies 397
5.2 Results 400
6 Conclusions and Outlook 401
References 403