文摘
英文文摘
CHAPTER 1 INTRoDUCTION
1.1 BACKGROUND
1.2 TUNGSTEN INERT GAS WELDING
1.3 MOTIVATION
1.4 RESEARCH OBJECTIVES
l.5 THESIS OUTLINE
CHAPTER 2 REVIEW OF METALLURGICAL EFFECTS OF WELDING
2.1 WELDING METALLURGY
2.1.1 The welding thermal cycle
2.1.2 The weld pool
2.1.3 Microstructure and properties of weld metals
2.1.4 Heat-affected zones in weld
2.2.ORIGIN OF THERMAL STRESSES
2.2.1 Residual Stresses in Weldments
2.2.2 Effects of residual stresses
2.3.RESIDUAL STRESS CONTROL METHODS
2.4 WELDING DEFORMATIONS
2.4.1 Transverse Shrinkage
2.4.2 Angular Distortion and Longitudinal Bowing
2.5 CONTROL OF DISTORTIONS
2.6 AISI 316 Stain less Steel
Summary
CHAPTER 3 HEAT FLOW IN WELDING
3.1 ANALYTICAL AND MATHEMA TICAL ANALYSIS OF WELDING HEAT INPUT
3.2 THE GENERALIZED EQUATION OF HEAT FLOW
3.3 ROSENTHAL'S SIMPLIFIED APPROACH
3.4 PEAK TEMPERATURES
3.5 COOLING RATES
3.6 MODELS FOR WELDING HEAT SOURCES
3.6.1 Gaussian Surface Flux Distribution
3.6.2 Hemi-spherical Power Density Distribution
3.6.3 Ellipsoid and double ellipsoid heat source models
Summary
CHAPTER 4 NUMERICAL SIMULATION OF TEMPERATURE FIELD OF T-JOINT
4.1 INTRODUCTION
4.2 THERMAL PROCESS DURINGWELDING：
4.3 FINITE ELEMENT ANALYSIS OF WELDING RESIDUAL STRESSES
4.4 MESH SENSITIVITY STUDY：
4.5 MATERIAL PROPERTY MODEL
4.6 Welding Process simulation of T-joint
4.7 THERMAL ANALYSIS
4.8 RESULTS AND DISCUSSIONS
4.9 WELD POOL SHAPE ANALYSlS
Summary
CHAPTER 5 NUMERICAL SIMULATION OF RESIDUAL STRESS FIELD AND DEFORMATION
5.1 SIMULATION OF WELDING
5.2 THERMO-MECHANICAL ANALYSIS
5.3 MECHANICAL BOUNDARY CONDITION
5.4 ANALYSIS OF RESIDUAL STRESSES DISTRIBUTION AND DISTORTION RESULTS
5.5 DEFORMATION ANALYSIS
CONCLUSION AND FUTURE WORK
CONCLUSION
FUTURE WORK
REFERENCES
ACKNOWLEDGEMENT
