Welding technology is considered as a reliable and efficient joining method, which has been widely used in almost all the industry departments. Detrimental factors induced by welding such as micro-cracks/flaws, tensile residual stresses, high stress concentration may degrade the mechanical and fatigue properties of weld joints. Ultrasonic impact treatment (UIT) is considered one of the most efficient post-weld treatment which could improve the fatigue performance of weld joints. In this study, the effect of the UIT on residual stress distribution of 304L weld joints was particularly investigated. FE analysis simulation and the XRD experiment were performed to predict and measure residual stresses of both as-welded and the UIT-treated joints. Compared results show that simulated stresses are in good agreement with the experimental results along various paths, confirming the validity of welding model. The UIT introduces a compressive residual stress layer with depth between 2 and 3 mm near the impacting surface of weld joint.

The ability to quantify residual stresses induced by welding processes through experimentation or numerical simulation has become, today more than ever, of strategic importance in the context of their application to advanced design. This is an ongoing challenge that commenced many years ago. Recent design criteria endeavour to quantify the effect of residual stresses on fatigue strength of welded joints to allow a more efficient use of materials and a greater reliability of welded structures. The aim of the present book is contributing to these aspects of design through a collection of case-studies that illustrate both standard and advanced experimental and numerical methodologies used to assess the residual stress field in welded joints. The work is intended to be of assistance to designers, industrial engineers and academics who want to deepen their knowledge of this challenging topic.

The ability to quantify residual stresses induced by welding processes through experimentation or numerical simulation has become, today more than ever, of strategic importance in the context of their application to advanced design. This is an ongoing challenge that commenced many years ago. Recent design criteria endeavour to quantify the effect of residual stresses on fatigue strength of welded joints to allow a more efficient use of materials and a greater reliability of welded structures. The aim of the present book is contributing to these aspects of design through a collection of case-studies that illustrate both standard and advanced experimental and numerical methodologies used to assess the residual stress field in welded joints. The work is intended to be of assistance to designers, industrial engineers and academics who want to deepen their knowledge of this challenging topic.

As a fabrication technology, welding presents a number of technical challenges to the designer, manufacturer, and end-user of the welded structures. Both weld residual stress and distortion can significantly impair the performance and reliability of the welded structures. They must be properly dealt with during design, fabrication, and in-service use of the welded structures. There have been many significant and exciting developments on the subject in the past ten to fifteen years. Measurement techniques have been improved significantly. More importantly, the development of computational welding mechanics methods has been phenomenal. The progresses in the last decade or so have not only greatly expanded our fundamental understanding of the processes and mechanisms of residual stress and distortion during welding, but also have provided powerful tools to quantitatively determine the detailed residual stress and distortion information for a given welded structure. New techniques for effective residual stress and distortion mitigations and controls have also been applied in different industry sectors. Processes and Mechanisms of Welding Residual Stress and Distortion provides a comprehensive summary on the developments in the subject. It outlines theoretical treatments on heat transfer, solid mechanics and materials behavior that are essential for understanding and determining the welding residual stress and distortion. The approaches for computational methods and analysis methodology are described so that non specialists can follow them. There are chapters devoted to the discussion of various techniques for control and mitigation of residual stress and distortion, and residual stress and distortion results for various typical welded structures are provided. The second half of the book looks at case studies and practical solutions and provides insights into the techniques, challenges, limitations and future trends of each application. This book will not only be useful for advanced analysis of the subject, but also provide sufficient examples and practical solutions for welding engineers. With a panel of leading experts this authoritative book will be a valuable resource for welding engineers and designers as well as academics working in the fields of structural and mechanical engineering.

Research goal of the present monograph is the establishment of an efficient engineering approach, which will include straightforward but accurate simulation models, in order to estimate the residual stress fields of welded joints introduced during welding and their post-weld treatment with High Frequency Hammer Peening. The present subject lies on the intersection of structural engineering, material science and computational mechanics.

Welding Deformation and Residual Stress Prevention, Second Edition provides readers with both fundamental theoretical knowledge about welding deformation and stress as well as unique computational approaches for predicting and mitigating the effects of deformation and residual stress on materials. This second edition has been updated to include new techniques and applications, outlining advanced finite element methods such as implicit scheme, explicit scheme, and hybrid scheme, and coupling analysis among thermal-metallurgy-mechanics. Non-destructive measurement methods for residual stresses are introduced, such as X-ray diffraction, the indentation technique, the neutron diffraction method, and various synchrotron X-ray diffraction techniques. Destructive measurement techniques are covered as well, such as block cutting for releasing residual stress, blind hole drilling, deep hole drilling, the slit cutting method, sectional contour method, and general inherent strain method. Various industrial applications of the material behavior and computational approaches are featured throughout. Focuses on the underlying theory, practical implementation, analysis and application of measurement techniques for welding deformation and residual stress Includes strategies for mitigation and control of deformation and stress Discusses cutting-edge computational methods for determining welding heat source, thermal process, phase transformation, welding thermal deformation, thermal stress, and residual states Outlines both non-destructive and destructive techniques for measuring residual stress Includes access to a companion site with code, simulation videos and other materials

The service performance and life of metal parts are closely related to the surface integrity of materials. Shot peening (SP) is a well-known surface strengthening technique and is widely used for the improvement of the component surface integrity in industrial fields, such as aerospace,vehicle, construction machinery and etc. With the rapid development of science and technology, numerous new SP techniques have been developed from the conventional mechanical shot peening, such as the laser shock peening (LSP), ultrasonic shot peening (USP),surface mechanical attrition treatment (SMAT) and etc. Different from the other mechanical processing techniques, a considerable number of process parameters have an influence on the surface strengthening effects of shot-peened metal parts. Therefore, the selection of the SP process parameters with respect to the different metal parts has always been a challenge. With the rapid development of the computer technology, the numerical simulation has increasingly attracted the more and more attentions both from the academy and the industry. Compared to the experimental investigations, the numerical simulations are not only timesaving and economical, but also can provide an insight into the surface strengthening mechanisms of SP.