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.

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.

Residual Stress Concentrations in a Stainless Steel Slot-Weld Measured by the Contour Method and Neutron Diffraction

2009 ◽  
Author(s):  
P. John Bouchard ◽  
Mark Turski ◽  
Mike C. Smith
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Neutron Diffraction ◽  
Structural Integrity ◽  
Measurement Techniques ◽  
Transverse Component ◽  
Contour Method ◽  
Stress Concentrations ◽  
Residual Stress Field ◽  
Concentration Effects

Arc-welding involves the deposition of molten filler metal and the localised input of intense heat. The surrounding parent material and, in the case of multi-pass welds, previously deposited weld metal, undergoes complex thermo-mechanical cycles involving elastic, plastic, creep and viscous deformations. These processes result in the development of large residual stress gradients around the welded region, which can be particularly detrimental to the structural integrity of plant components. The present study examines aggregated weld bead start and stop stress concentration effects in a three pass slot weld specimen that was designed to represent a multi-pass weld repair (without any original weld). The specimen design comprised a Type 316L stainless steel base-plate of nominal dimensions (300 × 200 × 25) mm3 with a 100 mm long by 10 mm deep central slot filled with 3 stringer manual metal arc weld beads, laid one on top of another. Residual stresses in three orthogonal directions were measured by neutron diffraction on a plane cutting through the centre of the plate, parallel to the welding direction, to show concentrations of tensile stress at both the weld start and stop positions. The transverse component of residual stress on the same plane in a second, nominally identical, specimen was mapped using the contour method. By applying two independent measurement techniques the residual stress field within the specimen type was determined with an increased level of confidence. Maximum transverse stress values of about 200 MPa at the weld start position and 300 MPa at the weld stop position were found. Peak tensile stresses in the longitudinal direction of 370 and 460 MPa were measured using neutron diffraction at the weld start and stop positions, respectively. The stresses measured by the contour method and neutron diffraction were in reasonable overall agreement with each other. However, the comparisons pointed to the possible presence of cutting artefacts in the contour results.

scholarly journals Plasticity and Stress Heterogeneity Influence on Mechanical Stress Relaxation Residual Stress Measurements

2014 ◽  
Vol 996 ◽  
pp. 249-255 ◽  
Author(s):  
Ho Kyeom Kim ◽  
Martyn J. Pavier ◽  
Anton Shterenlikht
Keyword(s):  
Residual Stress ◽  
Plastic Flow ◽  
Stress Measurement ◽  
Mechanical Strain ◽  
Image Correlation ◽  
Major Influence ◽  
Residual Stress Field ◽  
Fe Modelling ◽  
Full Field ◽  
Stress Uniformity

Two common problems of mechanical strain relaxation(MSR) residual stress measurement methods are investigated in this work:(1) assumption of stress uniformity and (2) the effect of plasticity at relaxation. A new MSR technique, designed specifically for highly non-uniformin-plane residual stress fields, is applied in this work to measure the residual stress field resulted from pure bending of an Al7075 alloy.The method involves introducing a straight cut across the whole part in a single increment, and collecting full field displacement fields from the side surface. Application of a 2D high resolution digital image correlation (DIC) method proved successful in this work.The reconstructed residual stress agrees well with that predicted by FE modelling. It is shown that the direction of the propagation of the slit has a major influence on plastic flow during relaxation.The major conclusion from this work is that it is possible to substantially reduce, or completely eliminate, plastic flow on relaxation by careful planning of the slit orientation and the cutting schedule.

A Validated Numerical Model for Residual Stress Predictions in an Eight-Pass-Welded Stainless Steel Plate

2014 ◽  
Vol 777 ◽  
pp. 46-51 ◽  
Author(s):  
Vipulkumar I. Patel ◽  
Ondrej Muránsky ◽  
Cory J. Hamelin ◽  
Mitch D. Olson ◽  
Michael R. Hill ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Stress Field ◽  
Steel Plate ◽  
Fe Analysis ◽  
Contour Method ◽  
Stainless Steel Plate ◽  
Residual Stress Field ◽  
Longitudinal Residual Stress ◽  
Welding Processes

Welding processes create a complex transient state of temperature that results in post-weld residual stresses. The current work presents a finite element (FE) analysis of the residual stress distribution in an eight-pass slot weld, conducted using a 316L austenitic stainless steel plate with 308L stainless steel filler metal. A thermal FE model is used to calibrate the transient thermal profile applied during the welding process. Time-resolved body heat flux data from this model is then used in a mechanical FE analysis to predict the resultant post-weld residual stress field. The mechanical analysis made use of the Lemaitre-Chaboche mixed isotropic-kinematic work-hardening model to accurately capture the constitutive response of the 316L weldment during the simulated multi-pass weld process, which results in an applied cyclic thermo-mechanical loading. The analysis is validated by contour method measurements performed on a representative weld specimen. Reasonable agreement between the predicted longitudinal residual stress field and contour measurement is observed, giving confidence in the results of measurements and FE weld model presented.

Numerical Modeling of AA2024-T3 Friction Stir Welding Process for Residual Stress Evaluation, Including Softening Effects

2014 ◽  
Vol 611-612 ◽  
pp. 1675-1682 ◽  
Author(s):  
Mads Rostgaard Sonne ◽  
Pierpaolo Carlone ◽  
Gaetano S. Palazzo ◽  
Jesper Henri Hattel
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Welding Process ◽  
Element Model ◽  
Transverse Cross Section ◽  
Heat Transfer Analysis ◽  
Contour Method ◽  
Friction Stir ◽  
Longitudinal Residual Stress ◽  
Numerical Finite Element

In the present paper, a numerical finite element model of the precipitation hardenable AA2024-T3 aluminum alloy, consisting of a heat transfer analysis based on the Thermal Pseudo Mechanical model for heat generation, and a sequentially coupled quasi-static stress analysis is proposed. Metallurgical softening of the material is properly considered and included in the calculations by means of the Myhr and Grong model, implemented as a user subroutine in ABAQUS. Numerical outcomes are compared with experimental results, highlighting the intriguing predictive capabilities of the model for both temperatures and residual stresses. The contour method is employed to map the longitudinal residual stress distribution on a transverse cross section of the joint. The influence of the applied boundary conditions and of the release of the clamping system on residual stresses is also assessed.

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.

Experimental Study of the Weld Residual Stress in Manually and Mechanically Fabricated Dissimilar Metal Weld

2018 ◽  
Author(s):  
Xinjian Duan ◽  
Andrew Glover ◽  
Dongmei Sun ◽  
Sanjooram Paddea
Keyword(s):  
Residual Stress ◽  
Experimental Study ◽  
Stress Measurement ◽  
Welding Process ◽  
Contour Method ◽  
Inconel 600 ◽  
Dissimilar Metal ◽  
Weld Residual Stress ◽  
Dissimilar Metal Weld ◽  
Metal Weld

The dissimilar metal welds between the Inconel 600 flow element and the SA-106 Grade B carbon pipe with Alloy 82 or Alloy 182 filler material of some CANDU® designs have been identified as being susceptible to Primary Water Stress Corrosion Cracking (PWSCC). Initiation and growth of PWSCC in a Dissimilar Metal Weld (DMW) are driven primarily by Welding Residual Stresses (WRS). The present paper focuses on the experimental study of weld residual stress distribution in manually and mechanically fabricated DMWs with emphasis on the effect of repair. A series of DMW samples are firstly fabricated in accordance with the original welding procedures for those DMWs in the field, which were fabricated in 1970s and 1980s. Multiple thermocouples were used to record the temperature evolution during the entire welding process. These samples were then examined by ASME qualified personnel in accordance with the requirements for Class 1 weld in Article 9 of Section V of ASME BVPC using Visual Testing (VT) and Radiography Testing (RT). Repair was then performed in some samples, and further NDE examinations were performed. The qualified samples (with and without repair) were finally subject to destructive weld residual stress measurement using contour method. It is observed that weld repair dramatically changes the distribution of weld residuals tress. The use of a constant through-thickness WRS of 60,000 psi (415 MPa) is justified as the bounding case.

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.

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