Download or read book Influence of Residual Stresses on Fatigue Crack Propagation in Electroslag Welds written by BM. Kapadia and published by . This book was released on 1978 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: An investigation of fatigue crack propagation behavior in air of as-deposited electroslag welds in two hot-rolled structural steels, prepared according to ASTM Specification for Structural Steel (A 36) and ASTM Specification for High-Strength Low-Alloy Structural Steel with 50 000 psi Minimum Yield Point to 4 in. Thick (Grade A) (A 588), has shown that the crack-growth rates (da/dN) in the welds were similar to or up to five times slower than the rate in the base steels. The retardation in crack-growth rate was observed to be substantially greater for crack propagation in the coarse-grained heat-affected-zone (HAZ) and bond-line regions than in the weld metal, but this was not consistently observed. Moreover, marked variations in the microstructure of the weld metal and HAZ did not significantly influence crack propagation. These crack-growth data for the weldments, described in an earlier paper, have been analyzed in the present paper in terms of residual stresses causing the observed retardation in crack-growth rate. In the present work, quantitative comparisons of the crack-growth behavior of the welds were based on a cyclic-life parameter (N1), which was defined as the number of cycles required for precracking the IT wedge-opening-loading (WOL) specimens to a total crack length of 2.54 cm (1 in.). This parameter gave results that were consistent with those based on incremental crack-growth (da/dN) data in the earlier paper. The observed retardation in crack-growth rate in the welds is attributed to compressive residual stresses introduced by welding. This effect was analyzed in the present paper in terms of a stress-intensity-range suppression concept, whereby the applied stress-intensity-factor range is decreased to some lower effective value. The results showed that the beneficial effect of compressive residual stresses on crack propagation appears to be of a variable nature and would diminish following a stress-relief heat treatment.

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 The Change of Fatigue Crack Propagation Rate Under the Influence of Residual Stresses written by V. I. Trufjakov and published by . This book was released on 1979 with total page 20 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 Early Fatigue Crack Growth at Welds written by C. C. Monahan and published by Computational Mechanics. This book was released on 1995 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fatigue Testing of Weldments written by David W. Hoeppner and published by ASTM International. This book was released on 1978 with total page 301 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 International Conference on Residual Stresses written by G. Beck and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 1043 pages. Available in PDF, EPUB and Kindle. Book excerpt: Residual stresses are always introduced in materials when they are produced, or when they undergo non-uniform plastic deformation during use. The circumstances that can cause residual stresses are therefore numerous. Residual stresses exist in all materials and, depending on their distribution, can playa beneficial role (for example, compressive surface stress) or have a catastrophic effect, especially on fatigue behaviour and corrosion properties. The subject of residual stresses took form around 1970 with the development of methods to measure macroscopic deformations during the machining of materials or on an atomic scale by X-ray diffraction. These techniques have made considerable progress in the last 20 years. The meetings organized in several countries (Germany, France, Japan, etc. ) have largely contributed to this progress, aided by the numerous exchanges of information and knowledge to which they have given rise. Studies of the formation of residual stresses began more slowly, but have progressed with the emergence of increasingly realistic models of materials behaviour and with access to ever more powerful codes for numerical calculations. Two successive meetings for discussing this topic have been held in Europe. The first, held in 1982 in Nancy (France), consisted of 30 participants from 5 countries. The second was held in Linkoping (Sweden) in 1984, with 80 participants of 16 nationalities. It was decided to hold a first International Conference, ICRS, to address all aspects of the problem. Held in 1986 in Garmisch-Partenkirschen (FRG), it was an assembly of neady 300 participants from 21 countries.

Download or read book Fatigue of Welded Structures written by Timothy Russell Gurney and published by CUP Archive. This book was released on 1979-12-20 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of residual stresses on the fatigue crack propagation in welded joints written by Nenad Gubeljak and published by . This book was released on 2005 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effect of residual stress on the fatigue crack growth was investigated for cyclic tension. Three-point bend specimens were used with through thickness notches at the center line of the welded joint. The experiments were performed for different load amplitudes and load ratios under conditions of small-scale yielding. The influence of the residual stresses on fatigue crack growth was estimated by experimentally observed fatigue crack growth rate and measurement of residual stresses at the surface of specimen. This paper describes an approach taken in two models to estimate the residual stress effect on fatigue crack propagation and to predict remaining service life of a welded structure.

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 Fatigue Life and Crack Propagation Analyses of Welded Components Containing Residual Stresses written by KN. Smith and published by . This book was released on 1977 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study deals with the fatigue of welded components emphasizing the use of small specimen data, a general stress-strain expression, the fatigue notch factor, and the effect of residual stresses. A computer-based fatigue damage analysis for welded structures is investigated; although accurate fatigue predictions have been made for notched structures, this type of analysis has not previously been applied to welded components. Fatigue crack propagation data are presented emphasizing the mean stress effect on the rate of cracking. Crack measurements have been made for both butt and fillet welded specimens in which the cracks commence from the toe of the weld.

Download or read book Stress Intensity Factor Analysis and Fatigue Behavior of a Crack in the Residual Stress Field of Welding written by Hiroyuki Terada and published by . This book was released on 2007 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper deals with the behavior of a crack in the residual stress field induced by butt weld in a wide plate. It is known that the distribution pattern of residual stress is similar regardless of welding process, though the size and the magnitude of the residual stress depend largely on the welding process. Stress intensity factor and stress redistribution induced by the crack extension were calculated for a crack with arbitrary length and location. The stress redistributions caused by crack extension obtained by the present analysis showed good agreement with the experimental data. Fatigue crack propagation behavior in the residual stress field reported by Glinka was also examined from the ?K point of view. In this paper, the effect of residual stress on the fatigue crack propagation rate is considered to be the effect of varying mean stress. The concept of ?Keff, where the effect of residual stress is accounted as the correction factor by the way of simple superposition, is shown to predict the crack growth rate with sufficient accuracy.

Download or read book Influence of Seawater and Residual Stresses on Fatigue Crack Growth in C Mn Steel Weld Joints written by Leonardo Bertini and published by . This book was released on 1991 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Assessment of Weld Residual Stress Effects on Fatigue Crack Propagation in Ferritic Pressure Vessel Steels written by Carlos Efren Jimenez Acosta and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Influence of Residual Stress on the Initiation of Fatigue Cracks at Welded Piping Joints written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Fatigue failures of small bore piping systems have historically occurred in nuclear power plants, resulting in unanticipated plant downtime and substantial financial loss. These failures have been reported with increasing frequency over the past 20 years and have motivated the research described in this thesis. Recent research at North Carolina State University (NCSU) pointed to the strain ratcheting response of the welded joint as a probable reason for fatigue failure and indicated that welding residual stresses might be responsible for inducing this strain ratcheting response. It was the primary objective in this investigation to determine what happens to residual stresses at the welded piping joint under the application of low-cycle fatigue loading and to understand how residual stresses induce strain ratcheting and thus affect the fatigue life of the welded joint. In order to achieve stated objectives, a systematic set of residual stress measurements and low-cycle fatigue tests was conducted. Initial residual stresses near the weld toe of six welded piping specimens were measured using the technique of x-ray diffraction. The specimens were then loaded in low-cycle fatigue to intermediate points in their fatigue lives and residual stresses were measured again. Strain response data near the weld toe was gathered throughout specimen fatigue life. Residual stress data and recorded strain responses in fatigue prompted conclusions concerning the role of residual stresses in inducing strain ratcheting which were verified by additional material level experiments. Initial residual stress measurements obtained from the welded specimens revealed that residual stresses near the weld toe--the location of fatigue crack initiation and final failure--were compressive in the overwhelming majority of measurement cases. It is widely accepted that compressive residual stresses are beneficial in fatigue. However, in this set of experiments, it was observed that compressive.