Contents
Preface
Chapter 1 Introduction 1
1.1 Research Background 1
1.2 Literature and Research Progress 4
1.2.1 Steel Cutting with Flame Heating 4
1.2.2 Plate Bending with High-Frequency Induction Heating 5
1.2.3 Welding Distortion Prediction in Shipbuilding 6
1.3 Research Content 12
Reference 12
Chapter 2 Fundamentals of FE Computation 18
2.1 Non-linear Thermal Elastic-Plastic FE Computation 19
2.1.1 Transient Thermal Analysis 19
2.1.2 Mechanical Analysis 20
2.1.3 Fast Computation Techniques 20
2.2 Theory of Inherent Strain and Deformation 23
2.2.1 Inherent Strain Theory 23
2.2.2 Inherent Deformation Theory 24
2.3 Interface Element 25
2.4 Elastic Buckling Theory 27
2.4.1 Finite Strain Theory 27
2.4.2 Eigenvalue Analysis 27
2.5 Tendon Force and Its Evaluation 30
2.5.1 Tendon Force Evaluation with Theoretical Analysis 32
2.5.2 Tendon Force Evaluation by Computed Results 33
2.6 Conclusions 35
Reference 36
Chapter 3 Investigation on Thick-Plate Cutting of High-Strength Steel 38
3.1 Research on Thermal Source Model of Oxygen and Acetylene cutting 38
3.1.1 Thermal Source Model 38
3.1.2 Determination of Thermal-Flow Distribution Parameters 39
3.1.3 Quasi-stable Temperature Field Under the Effect of Thermal Sources 40
3.1.4 Determination of Parameters in Thermal Source Model 40
3.2 Simulation of Rack Oxygen-Acetylene Cutting 41
3.2.1 Material Parameters of Temperature Properties 41
3.2.2 Finite Element Model of Rack 42
3.2.3 Calculation of Stress and Strain in Thermal Rack Cutting 43
3.3 Optimization of Cutting Process Parameters 45
3.4 Conclusions 48
Reference 49
Chapter 4 Hull Plate Bending with Induction Heating 50
4.1 Experimental Procedure and Measurement 50
4.1.1 Temperature Measurement During Induction Heating 51
4.1.2 Measurement of Bending Deformation 54
4.2 Measurement and Computational Analysis of Saddle Plate 56
4.2.1 Thermal Elastic-Plastic FE Computation 59
4.2.2 Evaluation of Bending Moment 61
4.2.3 Elastic FE Computation 62
4.3 Measurement and Computational Analysis of Sail Plate 64
4.3.1 TEP FE Analysis for Sail-Shape Plate 65
4.3.2 Elastic FE Analysis for Sail-Shape Plate 68
4.4 Conclusions 70
Reference 71
Chapter 5 Out-of-plane Welding Distortion Prediction for Typical Welded Joints and Ship Structures 72
5.1 Welding Distortion of Typical Fillet Welding 73
5.1.1 Experimental Procedure and Measurement 73
5.1.2 Thermal Elastic-Plastic FE Analysis 75
5.1.3 FE Computation on Influence of Lateral Stiffener 77
5.1.4 Inherent Deformation Evaluation 80
5.2 Welding Distortion of Stiffened Welded Structure 83
5.2.1 Fabrication of Orthogonal Stiffened Welded Structure 84
5.2.2 Elastic FE Analysis with Shell-Element Model 85
5.3 Conclusions 92
Reference 93
Chapter 6 Application of Computational Welding Mechanics for Accurate Fabrication of Ship Structure 94
6.1 Welding Distortion Reduction for Hatch Coaming Production 94
6.1.1 Experimental Procedure 97
6.1.2 Evaluation of Inherent Deformation of Fillet Welded Joints 99
6.1.3 Prediction of Welding Distortion of Hatch Coaming Using Elastic FE Analysis 102
6.2 Investigation on Welding Induced Buckling for Ship Panel Fabrication 104
6.2.1 Experimental Procedures and Measurement 104
6.2.2 Thermal Elastic-Plastic FE Computation of Fillet Welding 105
6.2.3 Evaluation of Welding Inherent Deformations 115
6.2.4 Elastic FE Analysis with Inherent Deformations 120
6.2.5 Techniques for Welding Buckling Prevention 126
6.3 Application of Accurate Fabrication for Container Ship 132
6.3.1 Examined Structures and Welding Experiments 134
6.3.2 Creation of Inherent Deformation Database 139
6.3.3 Prediction and Validation of Out-of-plane Welding Distortion 159
6.3.4 Influence of Welding Sequence on Precision Fabrication 163
6.3.5 X Groove Optimization of Butt Welded Joint with Thick Plates 167
6.4 Conclusions 176
Reference 178
Chapter 7 Application of Accurate Fabrication of Offshore Structure 180
7.1 Welding Distortion Prediction and Mitigation Practice of Cylindrical Leg Structure 180
7.1.1 Rack-cylinder Welding Experiment and Measurement 181
7.1.2 Welding Distortion Prediction with Efficient TEP FE Computation 184
7.1.3 Welding Distortion Mitigation with Bead-on-plate Techniques 190
7.2 Welding Distortion Prediction and Mitigation Practice of Cantilever Beam Structure 193
7.2.1 Establishment of Inherent Deformation Database 195
7.2.2 Welding Distortion Prediction with Elastic FE Analysis 203
7.2.3 Mitigation Implementation with Practical Techniques 205
7.3 Conclusions 211
Reference 212