The intense temperature fields caused by heat sources in welding frequently lead to distortions and residual stresses in the finished product. Welding distortion is a particular problem in fabricating thin plate structures such as ships. Based on pioneering research by the authors, Control of Welding Distortion in Thin-Plate Fabrication reviews distortion test results from trials and shows how outcomes can be modeled computationally. The book provides readers with an understanding of distortion influences and the means to develop distortion-reducing strategies.

The book is structured as an integrated treatment. It opens by reviewing the development of computational welding mechanics approaches to distortion. Following chapters describe the industrial context of stiffened plate fabrication and further chapters provide overviews of distortion mechanics and the modeling approach. A chapter on full-scale welding trials is followed by three chapters that develop modeling strategies through thermal process and thermo-mechanical simulations, based on finite-element analysis. Simplified models are a particular feature of these chapters. A final sequence of chapters explores the simulation of welding distortion in butt welding of thin plates and fillet welding of stiffened plate structures, and shows how these models can be used to optimize design and fabrication methods to control distortion.

Control of Welding Distortion in Thin-Plate Fabrication is a comprehensive resource for metal fabricators, engineering companies, welders and welding companies, and practicing engineers and academics with an interest in welding mechanics.

• Allows practitioners in the field to minimize distortion during the welding of thin plates
• Provides computational tools that can give insight into the effects of welding and fabrication procedures
• Demonstrates how welding distortion in thin plate fabrications can be minimized through design

Tom Gray is a Professor at the University of Strathclyde, UK.Duncan Camilleri is a Senior Lecturer at the University of Malta, Malta.Norman McPherson is a Welding Manager at BAE Systems, Surface Ships, UK.

Author contact details
Woodhead Publishing Series in Welding and Other Joining Technologies
Preface
1. Introduction: development of computational welding mechanics approach to welding distortion
Abstract:
1.1 Background: control of welding distortion in fabrication practice
1.2 Aims: integrated design approach utilising computational welding mechanics (CWM)
1.3 Structure of the book
1.4 Conclusion
1.5 References
2. Fabrication of stiffened thin-plate structures and the problem of welding distortion
Abstract:
2.1 Introduction
2.2 Welding distortion of stiffened-plate and other fabricated structures
2.3 Outline of a typical fabrication process
2.4 Raw materials and primary process factors
2.5 Management issues relevant to thin-plate distortion
2.6 Rectification of thin-plate distortion
2.7 Conclusion
2.8 References
3. Tools to deal with welding distortion: predictive modelling and research on in-process techniques
Abstract:
3.1 Introduction
3.2 Artificial neural networks (ANNs)
3.3 Computational simulation
3.4 Current research on reduction of distortion
3.5 Conclusion
3.6 References
4. Understanding welding distortion: thermal fields thermo-mechanical effects
Abstract:
4.1 Introduction
4.2 Thermal fields: dependence on welding parameters and material properties
4.3 Thermo-mechanical effects
4.4 Thermo-mechanical treatment based on longitudinal-transverse uncoupling
4.5 Plane strain strip: longitudinal deformations and forces
4.6 Transverse welding deformations
4.7 Residual stress
4.8 Buckling
4.9 Conclusion
4.10 References
5. Computational simulation of welding distortion: an overview
Abstract:
5.1 Introduction
5.2 Multi-physics
5.3 Thermal property non-linearity
5.4 Phase change and non-linear thermal dilatation
5.5 Mechanical property idealisation
5.6 Thermal computation outline
5.7 Range of thermo-mechanical approaches available
5.8 Reduced solutions and their advantages
5.9 Conclusion
5.10 References
6. Experimental investigation of models of welding distortion: methods, results and comparisons
Abstract:
6.1 Introduction
6.2 Importance of experimental observations
6.3 Welding process application in test work
6.4 Thermocouple arrays
6.5 Thermography
6.6 Deformation measurement
6.7 Completion and smoothing of measured deformation profiles
6.8 Characterising out-of-plane deformation
6.9 Conclusion
6.10 References
7. Modelling thermal processes in welding
Abstract:
7.1 Introduction
7.2 Convection and radiation
7.3 Heat input modelling
7.4 Simulation of weld deposition
7.5 Thermal property non-linearity
7.6 Three-dimensional transient thermal computation
7.7 Transient finite-element model based on two-dimensional cross-section
7.8 Thermal computation in stiffener fillet weld geometries
7.9 Welding efficiency
7.10 Thermal cutting
7.11 Conclusion
7.12 References
8. Computationally efficient methods for modelling welding processes
Abstract:
8.1 Introduction
8.2 Computationally efficient methods based on algorithms
8.3 Hybrid stepwise solution methods
8.4 Conclusion
8.5 References
9. Finite-element thermo-mechanical techniques for welding distortion prediction
Abstract:
9.1 Introduction
9.2 Formulation of thermo-mechanical finite-element model
9.3 Case study: influence of tacking procedures on butt-weld distortion
9.4 Case study: fillet-welded stiffened plate
9.5 Conclusion
9.6 References
10. Simulating welding distortion in butt welding of thin plates
Abstract:
10.1 Introduction
10.2 Plate support and out-of-flatness influences
10.3 Effects of tacking
10.4 Clamping effects
10.5 Residual stress in butt welds
10.6 Multiple butt welds
10.7 Conclusion
10.8 References
11. Simulating welding distortion in fillet welding of stiffened plate structures
Abstract:
11.1 Introduction
11.2 Plates with double-sided continuous fillet-welded single stiffeners: thermal aspects
11.3 Plates with double-sided continuous fillet-welded single stiffeners: computationally efficient thermomechanical treatment
11.