Download or read book Welding Techniques Distortion Control and Line Heating written by N. R. Mandal and published by . This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Welding techniques and associated weld distortion problems encountered in heavy industries are very typical and need to be dealt with from a view point of their requirements. This book covers in detail aspects of welding, distortion control and line heating in the context of heavy fabrication, shipbuilding and offshore industry and includes different welding methods used namely SMAW, GMAW, GTAW, SAW, Electrogas, Electroslag and Friction Stir Welding. This book discusses in detail weld induced distortion mechanism, types of distortions, their estimation using finite element analysis, various distortion control mechanisms namely controlled heat input, structural fit-up, thermal tensioning and heat sinking, effect of welding sequence on fabrication of stiffened panels.

Download or read book Welding and Distortion Control written by Nisith R. Mandal and published by Alpha Science International, Limited. This book was released on 2004 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: Welding and Distortion Control illustrates various welding methods with particular focus on shipbuilding, namely Sheet Metal Arc Welding (SMAW), Gas Metal Arc Welding (GMAW), Gas Tungsten Arc Welding (GTAW), Submerged Arc Welding (SAW) and Electro-slag along with single side and multi-electrode welding techniques. The chapter on welding distortion starts by explaining the distortion mechanism and subsequently introduces various types of distortions encountered and their prediction methods. Suitable distortion prediction tools have been explained to help welding engineers and structural designers to implement effective distortion control measures and to make production friendly designs for achieving the goal of near zero distortion in fabricated structures which will eliminate to a great extent the tedious post weld fairing work.

Download or read book Minimization of Welding Distortion and Buckling written by Pan Michaleris and published by Elsevier. This book was released on 2011-05-25 with total page 319 pages. Available in PDF, EPUB and Kindle. Book excerpt: Welding is a cost-effective and flexible method of fabricating large structures, but drawbacks such as residual stress, distortion and buckling must be overcome in order to optimize structural performance. Minimization of welding distortion and buckling provides a systematic overview of the methods of minimizing distortion and buckling in welded structures. Following an introductory chapter, part one focuses on understanding welding stress and distortion, with chapters on such topics as computational welding mechanics, modelling the effect of phase transformations on welding stress and distortion and using computationally efficient reduced-solution methods to understand welding distortion. Part two covers different methods of minimizing welding distortion. Chapters discuss methods such as differential heating for minimizing distortion in welded stiffeners, dynamic thermal tensioning, reverse-side heating and ways of minimizing buckling such as weld cooling and hybrid laser arc welding. With its distinguished editor and international team of contributors, Minimization of welding distortion and buckling is an essential reference for all welders and engineers involved in fabrication of metal end-products, as well as those in industry and academia with a research interest in the area. Provides a systematic overview of the methods of minimizing distortion and buckling in welded structures Focuses on understanding welding stress and distortion featuring computational welding mechanics and modelling the effect of phase transformations Explores different methods of minimizing welding distortion discussing differential heating and dynamic thermal tensioning

Download or read book Control of Distortion in Welded Fabrications written by Institute of Welding and published by Woodhead Publishing Limited. This book was released on 1968 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ship Construction and Welding written by Nisith R. Mandal and published by Springer. This book was released on 2016-11-09 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses various aspects of ship construction, from ship types and construction materials, to welding technologies and accuracy control. The contents of the book are logically organized and divided into twenty-one chapters. The book covers structural arrangement with longitudinal and transverse framing systems based on the service load, and explains basic structural elements like hatch side girders, hatch end beams, stringers, etc. along with structural subassemblies like floors, bulkheads, inner bottom, decks and shells. It presents in detail double bottom construction, wing tanks & duct keels, fore & aft end structures, etc., together with necessary illustrations. The midship sections of various ship types are introduced, together with structural continuity and alignment in ship structures. With regard to construction materials, the book discusses steel, aluminum alloys and fiber reinforced composites. Various methods of steel material preparation are discussed, and plate cutting and forming of plates and sections are explained. The concept of line heating for plate bending is introduced.Welding power source characteristics, metal transfer mechanisms, welding parameters and their effects on the fusion zone, weld deposit, and weld bead profile are discussed in detail. Various fusion welding methods, MMAW, GMAW, SAW, Electroslag welding and Electrogas welding and single side welding are explained in detail. Friction stir welding as one of the key methods of solid state welding as applied to aluminum alloys is also addressed. The mechanisms of residual stress formation and distortion are explained in connection with stiffened panel fabrication, with an emphasis on weld induced buckling of thin panels. Further, the basic principles of distortion prevention, in-process distortion control and mitigation techniques like heat sinking, thermo-mechanical tensioning etc. are dealt with in detail. In its final section, the book describes in detail various types of weld defects that are likely to occur, together with their causes and remedial measures. The nondestructive testing methods that are most relevant to ship construction are explained. Lastly, a chapter on accuracy control based on statistical principles is included, addressing the need for a suitable mechanism to gauge the ranges of variations so that one can quantitatively target the end product accuracy.

Download or read book Processes and mechanisms of welding residual stress and distortion written by Zhili Feng and published by CRC Press. This book was released on 2005-11-01 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Predictive Formulae for Weld Distortion written by G Verhaeghe and published by Woodhead Publishing. This book was released on 1999-09-21 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: &Quot;The quantification of the level of distortion that can be expected after welding has become crucial to meet the increasingly stringent accuracy requirements for the design of any type of fabricated component or structure. Many research workers have formulated weld distortion prediction models in order to reduce the extent of practical trials required to determine actual distortion. Because of the large number of prediction models available, some guidance is required on the selection of appropriate models for a particular welding application. For this reason, this review of published weld prediction formulae has been carried out within the Core Research Programme of TWI. Whilst reviews have been carried out in the past, this summary differs in that it covers four types of distortion - longitudinal shrinkage, bowing distortion, transverse shrinkage and angular distortion. It provides a critical assessment of each of the models; highlighting where background information exists, whether the model has been validated and possible limitations. Based on the information available for each of the models and on TWI's knowledge and experience, one or more models are recommended for each type of distortion."--BOOK JACKET.

Download or read book Distortion Control written by John P. Stewart and published by LaSalle, Quebec : J.P. Stewart. This book was released on 1989 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: Identifies different types of distortion of welded materials and describes techniques to be used to control and eliminate the distortion.

Download or read book Control of Welding Distortion written by Institute of Welding. Technical Sub-Committee D/1: Distortion and published by . This book was released on with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Control of Welding Distortion in Thin Plate Fabrication written by Tom Gray and published by Elsevier. This book was released on 2014-02-15 with total page 353 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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

Download or read book Investigation of Thermal Techniques to Mitigate Buckling Distortion in Welding Panels written by T. Nagy and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes the advancements of the application of thermal tensioning techniques to different weld geometries in order to eliminate buckling distortion. The main goal of this work is to better understand these techniques through experimental and numerical investigation and increase their technological maturity to aid industrial implementation. The thermal tensioning techniques investigated in this work are Thermal Tensioning by Cooling and Thermal Tensioning by Heating. The investigation for both techniques encompasses thermal source characterisation, application to different weld geometries and residual stress measurements and analysis of both butt and fillet welded samples. A detailed technology transfer study of Thermal Tensioning by Cooling was carried out in which different aspects of the application of TTC to arc welding (Gas Metal Arc Welding and Gas Tungsten Arc Welding) was examined. This study focused on the influence of both the liquid CO2 delivery system installation and welding tooling and jigging on the effectiveness of Thermal Tensioning by Cooling in reducing buckling distortion. Experimental and numerical cooling source characterisation was also carried out in the Thermal Tensioning by Cooling work to investigate the characteristics of the cooling source under different cooling conditions. The Thermal Tensioning by Cooling work was then concluded with welding trials and residual stress measurement and analysis. The results of the Thermal Tensioning by Cooling study show that the installation of the liquid CO2 delivery system as well as the welding tooling and jigging has a major influence on the effectiveness of Thermal Tensioning by Cooling in reducing buckling distortion. The cooling source characterisation work reveals that the most important parameter of the cryogenic nozzle delivery system used in this work is the Air Entrainment Gap. A description of a control system of Thermal Tensioning by Cooling is suggested based on controlling the Air Entrainment Gap. The residual stress analysis shows a reduction in the Applied Weld Load and minor changes in the tensile peak of the residual stress distribution of both butt and fillet welded panels. The Thermal Tensioning by Heating investigation includes heat source characterisation, application of Thermal Tensioning by Heating on butt and fillet welds, utilisation of alternative heat sources and residual stress analysis. The results of these investigation show that Thermal Tensioning by Heating is also highly effective in eliminating buckling distortion in butt, fillet and overlapped panels. The applied heating temperature in this work is typically in the range of 160-250 °C but not greater than 330 °C. The residual stress measurements reveal that the additional heating of Thermal Tensioning by Heating generates a positive stress gradient at the location of heating.

Download or read book Advances in Additive Manufacturing and Joining written by M. S. Shunmugam and published by Springer Nature. This book was released on 2019-10-16 with total page 749 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume presents research papers on additive manufacturing (popularly known as 3D printing) and joining which were presented during the 7th International and 28th All India Manufacturing Technology, Design and Research conference 2018 (AIMTDR 2018). The contents of this volume present the latest technological advancements for improving the efficiency, accuracy and speed of the additive manufacturing process and in fusion and solid-state welding technologies, with a variety of technologies, including fused deposition modelling, poly jet 3D printing, weld deposition based technology, selective laser melting and important welding technologies being covered. This volume will be of interest to academicians, researchers, and practicing engineers alike.

Download or read book Line Heating written by United States. Maritime Administration and published by . This book was released on 1982 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Control of Welding Distortion written by Institute of Welding and published by . This book was released on 1957 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Study on Distortion Control in Nozzle Welding of Stainless Steel Pressure Vessels written by Jinning Peng and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The welding of austenite stainless steel often results in large amount of welding distortion due to its high thermal expansion coefficient and low thermal conductivity. This has created great difficulty in the dimensional control of the welded stainless steel structure, ending up with high manufacturing cost. Researches on the welding distortion of stainless steels were very limited, especially for large weld structures with complex component shapes. The studies of this thesis were initiated with focus on the stainless steel nozzle-to-shell-can weld structures, a very typical structural configuration for pressure vessels used in petrochemical and nuclear power generation industries. Both the experimental and the FEA (finite element analysis), i.e. computational simulation, approaches were taken in the studies which addressed the influences of the welding fixture, the welding sequence, and the welding process on the distortion caused by stainless steel nozzle-to-shell welding. The investigations employed single and multi-nozzle weld test models (called mockups in the thesis) or FEA models. Manual GTAW (gas tungsten arc welding) and SMAW (shielded metal arc welding) processes were selected to represent the most common practice for stainless steel nozzle welding. The FEA simulations were conducted with ABAQUS program using sequentially coupled transient analysis method with lumped weld passes to achieve high computing efficiency. The investigations on the effect of the welding fixture concluded that the contour fixtures introduced in the thesis be effective for reducing the welding distortion for both the single and the multi-nozzle welding. The contour fixtures tend to localize the welding distortion, hence yield less impact on the global distortion of the whole weld structure. The rib-bar fixture, a more common fixture type for multi-nozzle welding, was found resulting in a big jump in the shell plate distortion when the fixture was removed. The studies on the influence of the welding sequence revealed that a progressive approach was more favorable for distortion control under the given nozzle-to-shell weld structure configurations. The best sequence suggested is to start welding at one nozzle, firstly on shell OD (outside diameter) side then on ID (inside diameter) side, then proceed to next neighboring nozzle. The effect of the welding direction of each weld pass was found affecting only the nozzle angular distortion. The experimental data showed that the manual GTAW process developed much higher shell plate distortion than the SMAW process. The reason would be that a higher percentage of the welding heat had been consumed on the base metal. The influence of the weld bead size didn't appear to be significant. In the FEA study on the effect of the size of the lumped weld pass, the increase in weld bead size even resulted in a decrease in weld distortion. From the FEA simulation point of view, using large lumped pass would be a highly efficient choice without compromising too much in the precision of the distortion prediction. The FEA study confirmed that a decrease in cooling time after welding would result in more welding distortion. The large scale multi-nozzle mockup with rib-bar fixture demonstrated a maximum out-of-plane shell distortion of 16.4mm after the welding of 10 nozzles with GTAW+SMAW process, which suggests that additional measures should be developed to further control the welding distortion.

Download or read book Design and Welding Engineer s Handbook on Weld Distortion Control written by Battelle Memorial Institute and published by . This book was released on 1971 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Distortion Control During Welding of Large Structures written by J. R. Stitt and published by . This book was released on 1964 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: