COMPUTATIONAL WELDING MECHANICSPDF电子书下载

Chapter Ⅰ：Introduction 1

1.1 Introduction and Synopsis 1

1.2 Brief history of computational welding mechanics 5

1.3 Mechanical behavior of welds 8

1.4 Major objective of this book 11

1.5 References 11

Chapter Ⅱ：Computer Simulation of Welding Processes 16

2.1 Introduction and Synopsis 16

2.2 The Computing Environment 18

2.2.1 Computational Geometry 18

2.2.2 Models for Welding Heat Sources 22

Theoretical Formulations 22

Model Considerations 24

Gaussian Surface Flux Distribution 26

Hemi-spherical Power Density Distribution 30

Ellipsoidal Power Density Distribution 30

Double Ellipsoidal Power Density Distribution 32

2.2.3 Kinematic Models for Welding Heat Transfer 35

2.2.4 Evaluation of the Double Ellipsoid Model 43

2.2.5 Modeling Thermal Stresses and Distortions in Welds 51

2.2.6 Microstructure Modeling in Heat Affected Zone （HAZ） 59

2.2.7 Spatial Integration Schemes 63

2.3 References 64

Chapter Ⅲ：Thermal Analysis of Welds 71

3.1 Introduction and Synopsis 71

3.2 Heat Transfer Theory 74

3.3 Weld Heat Source 76

3.3.1 Data to characterize a Weld Heat Source 77

3.3.2 Modeling a Weld Heat Source 79

First Generation Weld Heat Source Models 80

Second Generation Weld Heat Source Models 81

Distributed Heat Source Models 83

Prescribed Temperature Heat Source Models 83

Third Generation Weld Heat Source Models 84

Fourth Generation Weld Heat Source Models 85

Fifth Generation Weld Heat Source Model 86

Hierarchical Weld Process Models 87

3.4 Heat Transfer in Welds 87

3.4.1 Power Input 89

3.4.2 Implementation of prescribed temperature model 93

3.4.3 Starting Transient 94

3.4.4 Boundary Conditions 95

3.4.5 Finite Element Solutions with Prescribed Temperature 98

3.4.6 Computational Results 100

Complex Weld Pool Shape 100

Welds with Filler Metal Addition 108

3.5 References 115

Chapter Ⅳ：Evolution of Microstructure Depending On Temperature 119

4.1 Introduction and Synopsis 119

4.2 Microstructure Model 124

4.2.1 Data Structures 131

Flow lines 131

Functionality of the Data Structure 132

Layered tree description 132

Locating elements 135

Creating flow lines 136

4.2.2 Test Problems and Results 138

Steady State Temperature Field 140

Clipped transient temperature field 143

4.3 Hardness Calculation of the HAZ 148

4.4 References 149

Chapter Ⅴ：Evolution of Microstructure Depending On Deformations 153

5.1 Introduction and Synopsis 153

5.2 Properties for Modeling 158

5.2.1 Stresses，Strains and Deformations 162

5.2.2 Rate Independent Isotropic Plasticity 168

Steady-State Formulation 169

Deformation 172

Strain Increment Measurement 174

Numerical Results 176

5.2.3 Linear Viscous Isotropic Plasticity around melting pt 183

5.2.4 Rate dependent isotropic plasticity （General case） 184

5.2.5 Changing Constitutive Equations in Time and Space 185

5.2.6 Numerical Experiments and Results 186

5.3 References 195

Chapter Ⅵ：Carburized and Hydrogen Diffusion Analysis 199

6.1 Introduction and Synopsis 199

6.2 Carburization； Theory and Numerical Methods 203

6.2.1 Thermal，Microstructure and Stress Analysis 210

Thermal Analysis 210

Microstructure Analysis 211

Thermal Stress Analysis 211

Coupling Thermal，Microstructure and Stress Analysis 212

Test 212

Task Sequence 213

Structure and Materials 214

Deposition of Welds 214

FEM Mesh 215

Results and Discussion 217

6.3 Hydrogen Diffusion in Welds 226

6.3.1 Fundamental Equation 228

6.3.2 Preheat prediction 232

6.3.3 Computational Analysis 238

6.4 References 244

Chapter Ⅶ：Welded Structures and Applications of Welding in Industrial Fields 247

7.1 Introduction and Synopsis 247

7.2 Weld Procedure 249

7.3 Weld Joint 251

7.4 Analysis of a Weld Structure 252

7.5 Real-Time for CWM 266

7.5.1 Current Performance for CWM 269

7.5.2 Implications of real-time CWM 271

7.6 References 273

Chapter Ⅷ：Fracture Mechanics 277

8.1 Introduction and Synopsis 277

8.2 Review and Model Development 283

8.3 Discussion 300

8.4 References 302

Chapter Ⅸ：Input Data for Computational Welding Mechanics 305

9.1 Introduction and Synopsis 305

9.2 Structure to be Welded 305

9.3 Weld Procedure 307

9.4 Thermal Analysis Outside the Weld Pool 308

9.5 Microstructure Evolution 308

9.6 Thermal Stress Analysis Outside the Weld Pool 309

9.7 Weld Pool Solver 310

9.8 Material Properties Summary 311

9.9 Visualization 312

9.10 Fracture Mechanics of Welded Structures 312

Index 315