Download or read book Approach to Consider Welding Residual Stresses in Fatigue Analysis Using Numerical Simulations written by Nils Friedrich and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Although it is known that residual stresses may influence the fatigue strength of welded structures, they are usually not included explicitly in fatigue assessments. In this thesis the influence of welding residual stresses on fatigue is investigated using numerical simulations and experimental tests to develop an approach to consider welding residual stresses in fatigue analysis. A numerical welding simulation approach using a prescribed temperature heat source is described and the influence of various simulation parameters on the resulting residual stresses is assessed. The simulations are used to design small-scale specimens containing a multilayer K-butt weld and a longitudinal stiffener with tensile transversal residual stresses at the weld toe. Residual stresses are measured by X-ray diffraction and hole drilling on both specimen geometries and the simulation results are verified. Fatigue tests at different load ratios are conducted on both specimen geometries. The initiation of macroscopic cracks is detected using digital image correlation. The influence on crack initiation and propagation show differences for both investigated weld geometries. A correlation between the fatigue test results and the calculated stresses is found. Based on these findings an approach to predict S-N curves depending on the residual stress condition and stress ratio is developed. The approach is based on the presented numerical welding simulations and allows to consider the influence of welding residual stresses in fatigue analysis.
Download or read book Residual Stress Analysis on Welded Joints by Means of Numerical Simulation and Experiments written by Paolo Ferro and published by BoD – Books on Demand. This book was released on 2018-05-16 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Residual Stress Analysis on Welded Joints by Means of Numerical Simulation and Experiments written by Filippo Berto and published by . This book was released on 2018 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Computational Welding Mechanics written by John A. Goldak and published by Springer Science & Business Media. This book was released on 2006-07-04 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computational Welding Mechanics (CWM) provides readers with a complete introduction to the principles and applications of computational welding including coverage of the methods engineers and designers are using in computational welding mechanics to predict distortion and residual stress in welded structures, thereby creating safer, more reliable and lower cost structures. Drawing upon years of practical experience and the study of computational welding mechanics the authors instruct the reader how to: - understand and interpret computer simulation and virtual welding techniques including an in depth analysis of heat flow during welding, microstructure evolution and distortion analysis and fracture of welded structures, - relate CWM to the processes of design, build, inspect, regulate, operate and maintain welded structures, - apply computational welding mechanics to industries such as ship building, natural gas and automobile manufacturing. Ideally suited for practicing engineers and engineering students, Computational Welding Mechanics is a must-have book for understanding welded structures and recent technological advances in welding, and it provides a unified summary of recent research results contributed by other researchers.
Download or read book Fatigue Life Analyses of Welded Structures written by Tom Lassen and published by John Wiley & Sons. This book was released on 2013-03-01 with total page 442 pages. Available in PDF, EPUB and Kindle. Book excerpt: Avoiding or controlling fatigue damage is a major issue in the design and inspection of welded structures subjected to dynamic loading. Life predictions are usually used for safe life analysis, i.e. for verifying that it is very unlikely that fatigue damage will occur during the target service life of a structure. Damage tolerance analysis is used for predicting the behavior of a fatigue crack and for planning of in-service scheduled inspections. It should be a high probability that any cracks appearing are detected and repaired before they become critical. In both safe life analysis and the damage tolerance analysis there may be large uncertainties involved that have to be treated in a logical and consistent manner by stochastic modeling. This book focuses on fatigue life predictions and damage tolerance analysis of welded joints and is divided into three parts. The first part outlines the common practice used for safe life and damage tolerance analysis with reference to rules and regulations. The second part emphasises stochastic modeling and decision-making under uncertainty, while the final part is devoted to recent advances within fatigue research on welded joints. Industrial examples that are included are mainly dealing with offshore steel structures. Spreadsheets which accompany the book give the reader the possibility for hands-on experience of fatigue life predictions, crack growth analysis and inspection planning. As such, these different areas will be of use to engineers and researchers.
Download or read book Fatigue and Fracture of Weldments written by Uwe Zerbst and published by Springer. This book was released on 2018-12-11 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive and thorough guide to those readers who are lost in the often-confusing context of weld fatigue. It presents straightforward information on the fracture mechanics and material background of weld fatigue, starting with fatigue crack initiation and short cracks, before moving on to long cracks, crack closure, crack growth and threshold, residual stress, stress concentration, the stress intensity factor, J-integral, multiple cracks, weld geometries and defects, microstructural parameters including HAZ, and cyclic stress-strain behavior. The book treats all of these essential and mutually interacting parameters using a unique form of analysis.
Download or read book Numerical Simulation of Residual Stresses in Welding and Ultrasonic Impact Treatment Process written by Lanqing Tang and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book A Stress Analysis Method for Fatigue Life Prediction of Welded Structures written by Rakesh Kumar Goyal and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stress Determination for Fatigue Analysis of Welded Components written by E. Niemi and published by Woodhead Publishing. This book was released on 1995-04-30 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report introduces definitions of the terminology relevant to stress determination for fatigue analysis of welded components. The various stress concentrations, stress categories and fatigue analysis methods are defined. Fatigue analysis methods considered are nominal stress, hot spot stress, notch stress, notch strain and fracture mechanics approaches. The report also contains comprehensive recommendations concerning the application of finite element methods and experimental methods for stress determination. It is intended for fatigue design of common welded structures, such as cranes, excavators, vehicle frames, bridges, ship hulls, offshore structures etc. fabricated from materials at least 3mm thick. In general, attention is focused on weld details which give rise to fatigue cracking from the surface, notably from the weld toe.
Download or read book Residual Stresses 2018 written by Marc Seefeldt and published by Materials Research Forum LLC. This book was released on 2018-10-10 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: The European Conference on Residual Stresses (ECRS) series is the leading European forum for scientific exchange on internal and residual stresses in materials. It addresses both academic and industrial experts and covers a broad gamut of stress-related topics from instrumentation via experimental and modelling methodology up to stress problems in specific processes such as welding or shot-peening, and their impact on materials properties. Chapters: Diffraction Methods; Mechanical Relaxation Methods; Acoustic and Electromagnetic Methods; Composites, Nano and Microstructures; Films, Coatings and Oxides; Cold Working and Machining; Heat Treatments and Phase Transformations; Welding, Fatigue and Fracture: Stresses in Additive Manufacturing.
Download or read book A computational approach to thermomechanical fatigue life predictions of dissimilarly welded superheater tubes written by Ram Kumar Krishnasamy and published by GRIN Verlag. This book was released on 2012-09-06 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt: Doctoral Thesis / Dissertation from the year 2012 in the subject Engineering - Mechanical Engineering, grade: cum laude (gut), Karlsruhe Institute of Technology (KIT), course: Mechanical Engineering, language: English, abstract: The primary focus of this work is to investigate the influence of residual stresses on thermomechanical fatigue (TMF) life predictions. Both experimental and numerical methods have been adapted in order to predict the lifetimes of dissimilarly welded superheater tubing in power plants. The fatigue behavior and lifetime predictions of such components are complicated at high temperatures since a complex interaction between thermally activated, time-dependent processes are involved. At the same time, components that operate at elevated temperatures are often subjected to transient temperatures due to start-up and shut-down where thermally induced cyclic stresses can occur. The superposition of thermal transients with mechanical load cycles along with unequal heating of parts of a component result in a complex evolution of damage, leading to TMF failure of the component. To add to the complexity, the degradation mechanisms relevant to welded power plant components can be accelerated by the presence of residual stresses.
Download or read book Fatigue Assessment of Welded Joints by Local Approaches written by Dieter Radaj and published by Woodhead Publishing. This book was released on 2006-10-30 with total page 661 pages. Available in PDF, EPUB and Kindle. Book excerpt: Local approaches to fatigue assessment are used to predict the structural durability of welded joints, to optimise their design and to evaluate unforeseen joint failures. This standard work provides a systematic survey of the principles and practical applications of the various methods. It covers the hot spot structural stress approach to fatigue in general, the notch stress and notch strain approach to crack initiation and the fracture mechanics approach to crack propagation. Seam-welded and spot-welded joints in structural steels and aluminium alloys are also considered.This completely reworked second edition takes into account the tremendous progress in understanding and applying local approaches which has been achieved in the last decade. It is a standard reference for designers, structural analysts and testing engineers who are responsible for the fatigue-resistant in-service behaviour of welded structures. - Completely reworked second edition of a standard work providing a systematic survey of the principles and practical applications of the various methods - Covers the hot spot structural stress approach to fatigue in general, the notch stress and notch strain approach to crack initiation and the fracture mechanics approach to crack propagation. - Written by a distinguished team of authors
Download or read book Fatigue Analysis of Welded Components written by E. Niemi and published by Woodhead Publishing. This book was released on 2006-09-27 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report provides background and guidance on the use of the structural hot spot stress approach to the fatigue design of welded components and structures. It complements the IIW recommendations for 'Fatigue Design of Welded Joints and Components' and extends the information provided in the IIW recommendations on 'Stress Determination for Fatigue Analysis of Welded Components'. This approach is applicable to cases of potential fatigue cracking from the weld toe. It has been in use for many years in the context of tubular joints. The present report concentrates on its extension to structures fabricated from plates and non-tubular sections.Following an explanation of the structural hot spot stress, its definition and its relevance to fatigue, the authors describe methods for its determination. Stress determination from both finite element analysis and strain gauge measurements is considered. Parametric formulae for calculating stress increases due to misalignment and structural discontinuities are also presented. Special attention is paid to the use of finite element stress analysis and guidance is given on the choice of element type and size for use with either solid or shell elements. Design S-N curves for use with the structural hot spot stress are presented for a range of weld details. Finally, practical application of the recommendations is illustrated in two case studies involving the fatigue assessment of welded structures using the structural hot spot stress approach. - Provides practical guidance on the application of the structural hot-spot stress approach - Discusses stress determination from both finite element analysis and strain gauge measurements - Practical application of the recommendations is illustrated in two case studies
Download or read book Residual Stresses in Friction Stir Welding written by Nilesh Kulkarni and published by Butterworth-Heinemann. This book was released on 2013-11-20 with total page 59 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes the fundamentals of residual stresses in friction stir welding and reviews the data reported for various materials. Residual stresses produced during manufacturing processes lead to distortion of structures. It is critical to understand and mitigate residual stresses. From the onset of friction stir welding, claims have been made about the lower magnitude of residual stresses. The lower residual stresses are partly due to lower peak temperature and shorter time at temperature during friction stir welding. A review of residual stresses that result from the friction stir process and strategies to mitigate it have been presented. Friction stir welding can be combined with additional in-situ and ex-situ manufacturing steps to lower the final residual stresses. Modeling of residual stresses highlights the relationship between clamping constraint and development of distortion. For many applications, management of residual stresses can be critical for qualification of component/structure. - Reviews magnitude of residual stresses in various metals and alloys - Discusses mitigation strategies for residual stresses during friction stir welding - Covers fundamental origin of residual stresses and distortion
Download or read book Computational Concepts in Simulation of Welding Processes written by Reza Beygi and published by Springer Nature. This book was released on 2022-03-22 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces basic concepts related to computer-aided simulation of welding and prepares the reader to perform the simulation of welding by commercial simulation software. It focuses on conceptualizing the physics of welding, heat transfer, stress development and microstructure development in welding. This book helps the reader to implement these concepts in any commercial software to simulate the welding process according to their own requirement.
Download or read book Design and Analysis of Fatigue Resistant Welded Structures written by Dieter Radaj and published by Woodhead Publishing. This book was released on 1990-01-03 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: An English version of a sucessful German book. Both traditional and modern concepts are described.
Download or read book Computational Welding Mechanics written by Lars-Erik Lindgren and published by Elsevier. This book was released on 2014-01-23 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computational welding mechanics (CWM) provides an important technique for modelling welding processes. Welding simulations are a key tool in improving the design and control of welding processes and the performance of welded components or structures. CWM can be used to model phenomena such as heat generation, thermal stresses and large plastic deformations of components or structures. It also has a wider application in modelling thermomechanical and microstructural phenomena in metals. This important book reviews the principles, methods and applications of CWM.The book begins by discussing the physics of welding before going on to review modelling methods and options as well as validation techniques. It also reviews applications in areas such as fatigue, buckling and deformation, improved service life of components and process optimisation. Some of the numerical methods described in the book are illustrated using software available from the author which allows readers to explore CWM in more depth.Computational welding mechanics is a standard work for welding engineers and all those researching welding processes and wider thermomechanical and microstructural phenomena in metals. - Highlights the principles, methods and applications of CWM - Discusses the physics of welding - Assesses modelling methods and validation techniques
