Slitting and Contour Method Residual Stress Measurements in an Edge Welded Beam

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Foroogh Hosseinzadeh ◽  
Muhammed Burak Toparli ◽  
Peter John Bouchard
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Structural Integrity ◽  
Stress Measurement ◽  
Welding Process ◽  
Pressure Vessels ◽  
Contour Method ◽  
Residual Stress Field ◽  
Integrity Assessment ◽  
Stress Measurements

Welding is known to introduce complex three-dimensional residual stresses of substantial magnitude into pressure vessels and pipe-work. For safety-critical components, where welded joints are not stress-relieved, it can be of vital importance to quantify the residual stress field with high certainty in order to perform a reliable structural integrity assessment. Finite element modeling approaches are being increasingly employed by engineers to predict welding residual stresses. However, such predictions are challenging owing to the innate complexity of the welding process (Hurrell et al., Development of Weld Modelling Guidelines in the UK, Proceedings of the ASME Pressure Vessels and Piping Conference, Prague, Czech Republic, July 26–30, 2009, pp. 481–489). The idea of creating weld residual stress benchmarks against which the performance of weld modeling procedures and practitioners can be evaluated is gaining increasing acceptance. A stainless steel beam 50 mm deep by 10 mm wide, autogenously welded along the 10 mm edge, is a candidate residual stress simulation benchmark specimen that has been studied analytically and for which neutron and synchrotron diffraction residual stress measurements are available. The current research was initiated to provide additional experimental residual stress data for the edge-welded beam by applying, in tandem, the slitting and contour residual stress measurement methods. The contour and slitting results were found to be in excellent agreement with each other and correlated closely with published neutron and synchrotron residual stress measurements when differences in gauge volume and shape were accounted for.

Slitting and Contour Method Residual Stress Measurements in an Edge Welded Beam

2010 ◽  
Author(s):  
Foroogh Hosseinzadeh ◽  
P. John Bouchard ◽  
M. Burak Toparli
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Structural Integrity ◽  
Stress Measurement ◽  
Welding Process ◽  
Pressure Vessels ◽  
Contour Method ◽  
Residual Stress Field ◽  
Integrity Assessment ◽  
Stress Measurements

Welding is known to introduce complex three-dimensional residual stresses of substantial magnitude into pressure vessels and pipe-work. For safety-critical components, where welded joints are not stress-relieved, it can be of vital importance to quantify the residual stress field with high certainty in order to perform a reliable structural integrity assessment. Finite element modeling approaches are being increasingly employed by engineers to predict welding residual stresses. However, such predictions are challenging owing to the innate complexity of the welding process [1]. The idea of creating weld residual stress benchmarks against which the performance of weld modeling procedures and practitioners can be evaluated is gaining increasing acceptance. A stainless steel beam 50 mm deep by 10 mm wide, autogenously welded along the 10 mm edge, is a candidate residual stress simulation benchmark specimen that has been studied analytically and for which neutron and synchrotron diffraction residual stress measurements are available. The current research was initiated to provide additional experimental residual stress data for the edge-welded beam by applying, in tandem, the slitting and contour residual stress measurement methods. The contour and slitting results were found to be in excellent agreement with each other and correlated closely with published neutron and synchrotron residual stress measurements when differences in gauge volume and shape were accounted for.

scholarly journals Residual Stress Measurement in a Stainless Steel Clad Ferritic Plate Using the Contour Method

2013 ◽  
Author(s):  
Nida Naveed ◽  
Foroogh Hosseinzadeh ◽  
Jan Kowal
Keyword(s):  
Stainless Steel ◽  
Residual Stresses ◽  
Structural Integrity ◽  
Stress Measurement ◽  
Base Material ◽  
Pressure Vessels ◽  
Contour Method ◽  
Steel Weld ◽  
Integrity Assessment ◽  
Stainless Steel Weld

In pressure vessels stainless steel weld-overlay cladding is a widely used technique to provide a protective barrier between the corrosive environment and the ferritic low alloy base metal. While the cladding layers enhance corrosion resistance, the induced residual stresses due to the deposition of weld layers are of major concern. It is of paramount importance to understand how residual stresses interact with service loading when the vessel is pressurized. Therefore, knowledge of the initial residual stresses due to cladding is an essential input for structural integrity assessment of pressure vessels. In the present paper the Contour Method was conducted to measure residual stresses in an austenitic steel cladded plate that was fabricated from a ferritic steel base plate with three layers of austenitic stainless steel weld metal cladding deposited on the top surface. The Contour Method was chosen for various reasons. First, it provides a full 2D variation of residual stresses over the plane of interest. Second, it is not limited by the thickness of components or microstructural variations and finally it should potentially capture the variation of residual stresses in each individual weld beads and due to the possible phase transformation in the ferritic base material. The map of longitudinal residual stresses was measured by sectioning the test component along a transverse plane at mid-length. The measured residual stresses were in good agreement with published results in the open literature.

scholarly journals Should Residual Stresses Be Taken Into Account in Structural Integrity Assessment of Offshore Monopiles?

2018 ◽  
Author(s):  
Anais Jacob ◽  
Jeferson Araujo de Oliveira ◽  
Ali Mehmanparast ◽  
Foroogh Hosseinzadeh ◽  
Filippo Berto
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Structural Integrity ◽  
Stress Measurement ◽  
Corrosion Cracking ◽  
Residual Stress Measurement ◽  
Offshore Wind ◽  
Contour Method ◽  
Assessment Procedure ◽  
Integrity Assessment

A key challenge in the Offshore Wind industry is assuring the life-cycle structural integrity of wind turbine foundation monopiles. This is due to harsh environmental aspects as well as the loading regime (i.e. constant exposure to wave and wind forces introducing both fatigue and corrosion damage). Welding is a widely used joining technique for the manufacturing of offshore monopile structures. However, this is an aggressive process that introduces high levels of residual stress, which in turn may lead to reduced fatigue life, corrosion cracking resistance and accelerated degradation mechanisms. This study presents evidence that a measurement-informed strategy could be used towards developing a more reliable structural integrity assessment procedure for offshore monopile structures by taking into account the effect of residual stresses. A welded mock-up, 90 mm thick, 2600 mm wide and 800 mm long plate, was fabricated using a typical double-V welding procedure following current industrial practice. The contour method of residual stress measurement was employed to map residual stresses in the welded mock-up as well as in the CT specimens extracted from the weld region of the plate for future fatigue tests. Residual stress measurement results show that the mock-up plate contained tensile residual stresses above yield in the core of the weld, while the extracted CT specimens had lower though still significant residual stress levels. These results indicate that if the initial residual stresses are not carefully considered during fatigue or corrosion cracking tests, the results from the CT specimens alone will likely result in misleading structural life estimations.

Residual Stress Measurement Within a Single Pass Groove Weld Specimen Utilising Neutron Diffraction and the Contour Method

2006 ◽  
Author(s):  
Mark Turski ◽  
Lyndon Edwards ◽  
Jon James ◽  
Peter J. Bouchard ◽  
Mike Smith ◽  
...  
Keyword(s):  
Residual Stress ◽  
Neutron Diffraction ◽  
Stress Measurement ◽  
Welding Process ◽  
Parent Material ◽  
Weld Bead ◽  
Contour Method ◽  
Residual Stress Field ◽  
Full Field ◽  
Longitudinal Residual Stress

This paper describes the measurement of longitudinal residual stresses within a specially designed 200×180×25 mm single groove weld specimen. The purpose of these measurements was to quantify the residual stress field arising from a single stringer weld bead laid down within the constraint of a groove in order to validate finite element simulations of the welding process. Measurements were made over the cross section at the mid-bead length, utilising the relatively new Contour method and neutron diffraction. Non destructive neutron diffraction measurements were made using ENGIN-X, the engineering spectrometer at the ISIS facility of the Rutherford Appleton Laboratory (UK). The Contour method measurement was applied destructively at the Open University (UK), producing a detailed full-field residual stress map. Results from these measurements indicate a peak tensile longitudinal residual stress of ∼300 MPa within the parent material adjacent to the weld bead. Good agreement is found between both techniques.

Residual Stress Measurements in Single and Multi-Pass Groove Weld Specimens Using Neutron Diffraction and the Contour Method

2006 ◽  
Vol 524-525 ◽  
pp. 671-676 ◽  
Author(s):  
M. Kartal ◽  
Mark Turski ◽  
Greg Johnson ◽  
Michael E. Fitzpatrick ◽  
S. Gungor ◽  
...  
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Neutron Diffraction ◽  
Residual Stresses ◽  
Cross Section ◽  
Welding Process ◽  
Contour Method ◽  
Residual Stress Field ◽  
Process Measurements ◽  
Good Agreement

This paper describes the measurement of longitudinal residual stresses within specially designed 200x180x25mm groove weld specimens. The purpose of these measurements was to compare the residual stress field arising from single and multi-pass weld beads laid down within the constraint of a groove in order to validate finite element simulations of the welding process. Measurements were made over the cross section at the mid-bead length, utilising the relatively new Contour method and neutron diffraction. Results from these measurements indicate a larger peak tensile longitudinal residual stresses within the weld region of the multi-pass weld sample. Good agreement is found between both techniques.

scholarly journals Residual Stress Study for Sustainable Structural Integrity Assessment

2019 ◽  
Author(s):  
S Hossain ◽  
MD Salim Miah ◽  
B Fakhim
Keyword(s):  
Residual Stress ◽  
Hydrostatic Pressure ◽  
Residual Stresses ◽  
Structural Integrity ◽  
Welding Process ◽  
Surface Measurement ◽  
Hole Drilling ◽  
Near Surface ◽  
Integrity Assessment ◽  
Welding Processes

Marine structures are susceptible to failure mechanism due to presence of both external and internal loads. A submarine is manufactured with several circular hull sections welded together and forming an entire hull. A hull section consists of several bowed metal sheets welded together and strengthened by T-section rings which are welded at repeated spaces. T-section rings are fabricated using numerous web and flange plates and curved correctly by plastically bending before welding. Fatigue life of a submarine hull is dependent on load produced from hull contraction due to surrounding hydrostatic pressure, as well as residual stress present without any applied load. Numerical simulation can be used to calculate stresses generated from hydrostatic pressure. However, predicting residual stresses resulting from bending and welding processes can be more involved. Moreover, the predicted stresses need to be validated by measurement. Incremental centre-hole drilling (iCHD) is broadly applied technique to measure residual stress. The iCHD technique however is limited to near surface measurement which can contribute to misleading structural integrity assessment. On the other hand an over-conservative estimate of stress due to welding process can lead to reduced life estimate. It is thus imperative to analyse residual stresses accurately and deep into metal parts in order to move away from decade old conservative estimates. This paper reviews various techniques available for analysing residual stress field and considers multiple techniques with an aim to provide an optimum solution.

Manufacture, Residual Stress Measurement and Analysis of a VVER-440 Nozzle Mockup

2013 ◽  
Author(s):  
Levente Tatár ◽  
Gyula Török ◽  
David J. Smith ◽  
Son Do ◽  
Carsten Ohms ◽  
...  
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Stress Measurement ◽  
Welding Process ◽  
Full Scale ◽  
Residual Stress Measurement ◽  
Contour Method ◽  
Scale Model ◽  
Fe Model

As part of the STYLE EU FP7 project a modified 1:5 scale replica of a VVER-440 type reactor pressure vessel inlet nozzle was manufactured. The nozzle included a dissimilar metal weld of the type found in full-scale nozzles. This scale model was developed to permit accurate measurements to be made and detailed finite element (FE) models to be developed without recourse to using a full scale mock-up. It was also found that a full-scale mock-up would not permit the application of certain residual stress measurement methods. Temperatures and displacements were recorded during welding of the dissimilar metals, with measurements used to guide simulation of the welding process using finite element models. Through thickness residual stress profiles were measured using a comprehensive range of different techniques, such as deep hole drilling, neutron diffraction, magnetic Barkhausen noise. Usage of contour method had been planned too, but it but could not be accomplished in due time. The measured residual stresses obtained by the different methods are presented and compared. Measured residual stresses, temperatures and displacements were then used to validate the results derived from the FE model.

Advances in Residual Stress Modeling and Measurement for the Structural Integrity Assessment of Welded Thermal Power Plant

2008 ◽  
Vol 41-42 ◽  
pp. 391-400 ◽  
Author(s):  
Lyndon Edwards ◽  
Mike C. Smith ◽  
Mark Turski ◽  
Michael E. Fitzpatrick ◽  
P. John Bouchard
Keyword(s):  
Residual Stress ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Residual Stresses ◽  
Nuclear Power ◽  
Structural Integrity ◽  
Pressure Vessels ◽  
Economic Life ◽  
Life Assessment ◽  
Integrity Assessment

The safe operation of both thermal and nuclear power plant is increasingly dependent upon structural integrity assessment of pressure vessels and piping. Furthermore, structural failures most commonly occur at welds so the accurate design and remnant life assessment of welded plant is critical. The residual stress distribution assumed in defect assessments often has a deciding influence on the analysis outcome, and in the absence of accurate and reliable knowledge of the weld residual stresses, the design codes and procedures use assumptions that yield very conservative assessments that can severely limit the economic life of some plant. However, recent advances in both the modeling and measurement of residual stresses in welded structures and components open up the possibility of characterising weld residual stresses in operating plant using state-of–the–art fully validated Finite Element simulations. This paper describes research undertaken to predict residual stresses in stainless steel welds in order to provide validated reliable, accurate Structural Integrity assessment of nuclear power plant components

Assessment of the Influence of Plasticity and Constraint on Measured Residual Stresses Using the Contour Method

2008 ◽  
Author(s):  
R. J. Dennis ◽  
D. P. Bray ◽  
N. A. Leggatt ◽  
M. Turski
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Stress Measurement ◽  
General Procedure ◽  
Relaxation Method ◽  
Cutting Process ◽  
Contour Method ◽  
Hole Drilling ◽  
Residual Stress Field ◽  
Rigid Constraint

The contour method is a relatively new relaxation method for residual stress measurement and may be seen as an evolution of established methods such as hole drilling. The general procedure when applying the contour method is cutting, measurement and calculation of residual stress normal to the cut plane using Bueckner’s principle of elastic superposition. That is the residual stresses are determined from the measured profile of a cut surface. While the contour method is simple in concept there are certain underlying issues relating to the cutting process that may lead to uncertainties in the measured results. Principally the issues are that of constraint and plasticity during cutting and the influence they have on the measured residual stresses. In this paper both issues are investigated in detail by simulating the entire contour method process using finite element techniques for two welded specimens. Constraint has been a recognised concern for the contour method with the general requirement being to hold the specimen as rigidly as possible. Both clamping and fixing bolts are routinely used however in reality these methods do not provide a fully rigid constraint. In this work a range of constraints have been examined to determine the influence on the measured residual stresses. Plasticity, as a consequence of the cutting process, has also been recognised as a factor which may affect the measured residual stresses. In this work the extent of plasticity is predicted by simulation of the cutting process. With a known initial residual stress field the effects of plasticity are directly quantifiable. This work therefore provides an extremely useful insight into some of the key issues that affect the measurement performance of the contour method.

scholarly journals Residual stresses in thermite welded rails: significance of additional forging

2020 ◽  
Vol 64 (7) ◽  
pp. 1195-1212
Author(s):  
B. Lennart Josefson ◽  
R. Bisschop ◽  
M. Messaadi ◽  
J. Hantusch
Keyword(s):  
Residual Stress ◽  
Stress Field ◽  
Residual Stresses ◽  
Weld Metal ◽  
Welding Process ◽  
Surface Zone ◽  
Fe Model ◽  
Uneven Surface ◽  
Residual Stress Field ◽  
High Dynamic

Abstract The aluminothermic welding (ATW) process is the most commonly used welding process for welding rails (track) in the field. The large amount of weld metal added in the ATW process may result in a wide uneven surface zone on the rail head, which may, in rare cases, lead to irregularities in wear and plastic deformation due to high dynamic wheel-rail forces as wheels pass. The present paper studies the introduction of additional forging to the ATW process, intended to reduce the width of the zone affected by the heat input, while not creating a more detrimental residual stress field. Simulations using a novel thermo-mechanical FE model of the ATW process show that addition of a forging pressure leads to a somewhat smaller width of the zone affected by heat. This is also found in a metallurgical examination, showing that this zone (weld metal and heat-affected zone) is fully pearlitic. Only marginal differences are found in the residual stress field when additional forging is applied. In both cases, large tensile residual stresses are found in the rail web at the weld. Additional forging may increase the risk of hot cracking due to an increase in plastic strains within the welded area.

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