Influence of welding parameters on the welding residual stresses

FE simulation of welds from austenitic steel was carried out in the current paper. Two different multi-pass welds were modelled. Measurements of welding residual stresses, which were found in literature, were applied for the validation of the results. The validated models were then used as basis for sensitivity analysis. The influence of differentiating the welding speed, the heat input of the weld heat source, intermediate cooling between consecutive weld-passes and welding sequence on the welding residual stresses was investigated

Application of high frequency mechanical impact treatment to improve the fatigue strength of corroding welded joints

This study deals with the fatigue strength of high-frequency mechanical impact (HFMI)-treated unprotected structural details made of mild steel S355 considering the influence of corrosive environmental conditions. The investigations are carried out on butt welded specimens with sheet thickness t = 15 mm and on transverse non-load-carrying attachment specimens with sheet thickness t = 25 mm. Two different methods were applied for the simulation of marine corrosive environment in the laboratory. Specimens first were deposited in a salt spray chamber and then tested subsequently dry at laboratory-air conditions considering the influence of corrosion on the crack initiation. Alternatively, and to cover the effects of corrosion on the crack growth, artificial seawater was used for pre-corrosion, and after a defined timespan, fatigue tests were performed simultaneously with the specimen resting in the corrosive medium. The corrosion fatigue tests were performed in as-welded and HFMI-treated conditions at a stress ratio R = 0.1 under axial tensile and 4-point bending cyclic loading. The test results are evaluated to determine the characteristic fatigue strengths for fixed slopes m = 3 and m = 5 according to IIW recommendations for the as-welded and for the HFMI-treated condition respectively. The results of the experimental investigations based on the nominal stress approach show that the fatigue strength of both specimen types could be significantly increased by the application of HFMI treatment compared to the corresponding specimens in the as-welded condition even if exposed to the investigated corrosive conditions. The comparison with the design proposals of IIW shows that for HFMI-treated butt welds, no reduction of the FAT class due to corrosion is required and the recommended FAT class is still valid. The results for the HFMI-treated transverse attachments are slightly below the design curve recommended by IIW and a proposal to consider corrosion is derived for this case. Additional numerical investigations by applying the effective notch stress (ENS) approach are performed to determine notch stress curves. It was found that for the corroded specimens in the as-welded condition, the FAT class according to IIW could not be reached and adjustments of the existing rules are necessary to consider corrosion effects. However, it can be concluded that the effective notch fatigue resistance recommended by IIW is still applicable in the case of corroded HFMI-treated structural details

Influence of welding parameters on the welding residual stresses

FE simulation of welds from austenitic steel was carried out in the current paper. Two different multi-pass welds were modelled. Measurements of welding residual stresses, which were found in literature, were applied for the validation of the results. The validated models were then used as basis for sensitivity analysis. The influence of differentiating the welding speed, the heat input of the weld heat source, intermediate cooling between consecutive weld-passes and welding sequence on the welding residual stresses was investigated

Das Beulverhalten von biegebeanspruchten Zylinderschalen mit grossen Manteloeffnungen

SIGLETIB: RA 1604 (4,12) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Massnahmen der nachhaltigen Gefahrenabwehr fuer Altlasten in Gebieten mit bergbaubedingten Destabilisierungsvorgaengen am Beispiel der Stadt Stassfurt Laufzeit des Verbundvorhabens 01.10.2000-28.02.2002

Ziel des Vorhabens war die interdisziplinaere Zusammenfassung, Analyse und Bewertung vorliegender Einzelergebnisse, die aufgabenbezogene Evaluierung von verfuegbaren Methoden, Forschungsansaetzen und Loesungen, die Durchfuehrung ergaenzender Untersuchungen und methodischer Tests sowie die Feststellung des weiteren Forschungs- und Handlungsbedarfs. (orig.)The project comprised an interdisciplinary assessment, analysis and evaluation of research findings, a problem-oriented evaluation of available methods, research strategies and solutions, supplementary investigations and methodical tests, and an assessment of the need for further research and actions.Available from TIB Hannover: F03B366 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung und Forschung, Berlin (Germany); Ministerium fuer Wirtschaft und Technologie des Landes Sachsen-Anhalt, Magdeburg (Germany)DEGerman

Massnahmen der nachhaltigen Gefahrenabwehr fuer Altlasten in Gebieten mit bergbaubedingten Destabilisierungsvorgaengen am Beispiel der Stadt Stassfurt Laufzeit des Verbundvorhabens 01.10.2000-28.02.2002

Ziel des Vorhabens war die interdisziplinaere Zusammenfassung, Analyse und Bewertung vorliegender Einzelergebnisse, die aufgabenbezogene Evaluierung von verfuegbaren Methoden, Forschungsansaetzen und Loesungen, die Durchfuehrung ergaenzender Untersuchungen und methodischer Tests sowie die Feststellung des weiteren Forschungs- und Handlungsbedarfs. (orig.)The project comprised an interdisciplinary assessment, analysis and evaluation of research findings, a problem-oriented evaluation of available methods, research strategies and solutions, supplementary investigations and methodical tests, and an assessment of the need for further research and actions.Available from TIB Hannover: F03B366 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung und Forschung, Berlin (Germany); Ministerium fuer Wirtschaft und Technologie des Landes Sachsen-Anhalt, Magdeburg (Germany)DEGerman