Download or read book Influence of Residual Stress on the Predicted Fatigue Life of Weldments written by JD. Burk and published by . This book was released on 1982 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: A model was developed that predicts the influence of residual stress and stress ratio on the total fatigue life of a weld. The total fatigue life of a weld was considered to be composed of both crack initiation and crack propagation. Weld toe residual stresses were considered to influence the crack initiation life but not the crack propagation life.

Download or read book Residual Stress Effects in Fatigue written by H. S. Reemsnyder and published by ASTM International. This book was released on 1982 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effect of Residual Stresses on Weld Fatigue Life written by J. D. Burk and published by . This book was released on 1978 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fatigue Testing of Weldments written by D. W. Hoeppner and published by ASTM International. This book was released on 1978 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Heat Effects of Welding written by Dieter Radaj and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 367 pages. Available in PDF, EPUB and Kindle. Book excerpt: Almost all welding technology depends upon the use of concentrated energy sources to fuse or soften the material locally at the joint, before such energy can be diffused or dispersed elsewhere. Although comprehensive treatments of transient heat flow as a controlling influence have been developed progressively and published over the past forty years, the task of uniting the results compactly within a textbook has become increasingly formidable. With the comparative scarcity of such works, welding engineers have been denied the full use of powerful design analysis tools. During the past decade Dr Radaj has prepared to fulfil this need, working from a rich experience as pioneer researcher and teacher, co-operator with Professor Argyris at Stuttgart University in developing the finite element method for stress analysis of aircraft and power plant structures, and more recently as expert consultant on these and automotive structures at Daimler Benz. His book appeared in 1988 in the German language, and this updated English language edition will significantly increase the availability of the work.

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 Fracture and Fatigue of Welded Joints and Structures written by K Macdonald and published by Elsevier. This book was released on 2011-04-19 with total page 353 pages. Available in PDF, EPUB and Kindle. Book excerpt: The failure of any welded joint is at best inconvenient and at worst can lead to catastrophic accidents. Fracture and fatigue of welded joints and structures analyses the processes and causes of fracture and fatigue, focusing on how the failure of welded joints and structures can be predicted and minimised in the design process.Part one concentrates on analysing fracture of welded joints and structures, with chapters on constraint-based fracture mechanics for predicting joint failure, fracture assessment methods and the use of fracture mechanics in the fatigue analysis of welded joints. In part two, the emphasis shifts to fatigue, and chapters focus on a variety of aspects of fatigue analysis including assessment of local stresses in welded joints, fatigue design rules for welded structures, k-nodes for offshore structures and modelling residual stresses in predicting the service life of structures.With its distinguished editor and international team of contributors, Fracture and fatigue of welded joints and structures is an essential reference for mechanical, structural and welding engineers, as well as those in the academic sector with a research interest in the field. - Analyses the processes and causes of fracture and fatigue, focusing predicting and minimising the failure of welded joints in the design process - Assesses the fracture of welded joints and structure featuring constraint-based fracture mechanics for predicting joint failure - Explores specific considerations in fatigue analysis including the assessment of local stresses in welded joints and fatigue design rules for welded structures

Download or read book Model Analysis of Fatigue Life Estimation of Welded Structures microform written by Muhammad A. Wahab and published by National Library of Canada. This book was released on 1984 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study includes both an experimental and theoretical analysis of the effect of residual stresses on the fatigue life of butt-welded low-alloy steel structures. The purpose is to develop a more complete method to estimate the total fatigue life of a weldment. To theoretically calculate the total fatigue life the process was considered as a combination of crack initiation and crack propagation lives. The initiation portion was based on an extension of the local-strain fatigue life initiation model to accomodate the effect of residual and mean stresses. To determine the local notch-root stress-strain condition more accurately a relationship between the fatigue notch and stress concentration factors was developed. Using elastic superposition and modifying Neuber's equation, which relates nominal stress-strain to local notch-root stress-strain residual stresses at the weld-toe were simulated. This analysis allows a more complete estimation of crack initiation life. For the theoretical analysis of fatigue crack propagation life Forman's equation with an appropriate combination effective stress ratio, axial and bending stresses along with residual stress effects was considered. To incorporate the residual stress distribution at the weld-toe a theoretical expression which correlates closely with experimentally determined distributions was developed. Unlike previous investigations this analysis allows the study of the combined effects of axial loading, bending stresses and residual stresses on the fatigue crack propagation life to be considered. With this theoretical model the total fatigue life can be predicted using basic material properties and the loading history including any surface treatment. To test the suitability of this analysis it was applied to welds with mechanically and thermally induced surface stresses. The residual stresses due to various treatments (annealing, tensile preloading, glass and steel shot peening, single and multiple point hammer peening and stress peening) were used to theoretically predict the total fatigue life. The more complete theoretical analysis of the total fatigue life was compared to the experimental results for all the treated and untreated welded specimens. The results show very good agreement; the variations in applied stress for a given fatigue life were between four to 15% for all the treatments listed above.

Download or read book IIW Recommendations On Methods for Improving the Fatigue Strength of Welded Joints written by P J Haagensen and published by Woodhead Publishing. This book was released on 2013-01-25 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt: The weld toe is a primary source of fatigue cracking because of the severity of the stress concentration it produces. Weld toe improvement can increase the fatigue strength of new structures significantly. It can also be used to repair or upgrade existing structures. However, in practice there have been wide variations in the actual improvements in fatigue strength achieved. Based on an extensive testing programme organised by the IIW, this report reviews the main methods for weld toe improvement to increase fatigue strength: burr grinding, TIG dressing and hammer and needle peening. The report provides specifications for the practical use of each method, including equipment, weld preparation and operation. It also offers guidance on inspection, quality control and training as well as assessments of fatigue strength and thickness effects possible with each technique. IIW recommendations on methods for improving the fatigue strength of welded joints will allow a more consistent use of these methods and more predictable increases in fatigue strength. Provides specifications for the practical use of each weld toe method, including equipment, weld preparation and operation Offers guidance on inspection, quality control and training, as well as assessments of fatigue strength and thickness effects possible with each technique This report will allow a more consistent use of these methods and more predictable increases in fatigue strength

Download or read book Residual Stress Effects in Fatigue written by and published by . This book was released on 1982 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of Residual Stresses on Fatigue Crack Growth in Steel Weldments Under Constant and Variable Amplitude Loads written by G. Glinka and published by . This book was released on 1979 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: The research deals with the effect of welding residual stresses on fatigue crack growth in medium strength low alloy steel weldments. Three kinds of flat specimens have been used--unwelded specimens, specimens with butt perpendicular welds, and specimens with butt longitudinal welds. Residual stress distributions were others in both kinds of welded specimens. All specimens were tested under constant and variable amplitude load with stress ratios R > 0. Forman's equation and Wheeler's model of crack retardation were used for theoretical analysis of fatigue crack growth under constant and variable amplitude load, respectively. The theoretical results were more realistic when effective stress ratio Reff and effective stress intensity range ?Keff, which compensated for residual stresses, were used. It was found that the tensile residual stresses increased the fatigue crack growth rate and compressive stresses reduced it. The lower the applied load, the higher the residual stress effect. This paper presents both experimental results and an analytical method of fatigue crack growth prediction in steel weldments on the basis of results obtained from parent material properties.

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 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 Residual Stress Effects on Fatigue Life Via the Stress Intensity Parameter K written by Jeffrey L. Roberts and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Residual stresses are known to have a significant effect on fatigue crack propagation and thus fatigue life. These effects have generally been quantified through an empirical approach, lending little help in the quantitative prediction of such effects. The weight function method has been used as a quantitative predictor, but its use neglects residual stress redistribution, treating the residual stress as a constant during crack growth. At least three different behaviors contribute to the redistribution of residual stress. First, the residual stress behind the crack tip is reduced to a negligible level as soon as the crack tip passes. Second, the residual stress tends to redistribute away from the crack tip with crack growth, and third, crack growth results in an overall relaxation of residual stress. An alternative method for predicting the effect of a residual stress distribution on fatigue crack growth is herein developed. The stress intensity factor due to residual stress, K[subscript res], is characterized as the change in crack driving force due to the presence of the residual stress. This crack driving force, being the derivative of a potential, is found through superposition of an applied stress and a residual stress, and subsequent manipulation of finite element strain energy and nodal displacement results. Finite element modeling is carried out using a spatial distribution of non-uniform thermal expansion coefficients and a unit temperature load to simulate the desired residual stress. Crack growth is then achieved through use of a node release algorithm which sequentially removes nodal displacement constraint. The complete stress distribution, nodal displacements and internal strain energy are captured for each increment of crack growth, and from this information, knowledge of the stress intensity factor as a function of crack length is derived. Results of the K[subscript res] calculations are used in a fatigue crack growth model to predict fatigue lives. The fatigue life model involves step by step analysis of crack growth increment based on knowledge of stress intensity factors resulting from applied and residual stress. The qualitative effects of residual stress predicted by this model agree with documented empirical results which show that compressive residual stress increases fatigue life, while tensile residual stress decreases fatigue life. Two solutions for K[subscript res] are possible, depending on the choice of load-control or displacement-control modeling. Use of displacement-control, or fixed displacement loading, minimizes redistribution of residual stress and, under net tensile loading, tends to lead to more conservative fatigue life predictions. Load-control modeling, not having the same displacement constraint, allows more relaxation of the residual stress and tends to provide the more non-conservative life estimates. Three residual stress patterns, two due to welding and one to shot peening, are also investigated. K[subscript res] solutions for each residual stress are developed, and fatigue life predictions made.

Download or read book The Influence of Residual Stresses on the Fatigue Strength of Welded Steel Structures written by T. R. Gurney and published by . This book was released on 1956 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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.