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Michael E. Fitzpatrick - One of the best experts on this subject based on the ideXlab platform.
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Minimization and Mitigation of Wire EDM Cutting Errors in the Application of the Contour Method of Residual Stress Measurement
Metallurgical and Materials Transactions A, 2015Co-Authors: Bilal Ahmad, Michael E. FitzpatrickAbstract:The Contour Method of residual stress measurement relies on the careful application of wire electro-discharge machining (WEDM) for the cutting stage. Changes in material removal rates during the cut lead to errors in the final calculated values of residual stress. In this study, WEDM cutting parameters have been explored to identify the optimum conditions for Contour Method residual stress measurements. The influence of machine parameters on the surface roughness and cutting artifacts in the Contour cut is discussed. It has been identified that the critical parameter in improving the surface finish is the spark pulse duration. A typical cutting artifact and its impact on measured stress values have been identified and demonstrated for a Contour cut in a welded marine steel. A procedure is presented to correct Contour displacement data from the influence of WEDM cutting artifacts, and is demonstrated on the correction of a measured weld residual stress. The corrected Contour Method improved the residual stress magnitude up to 150 MPa. The corrected Contour Method results were validated by X-ray diffraction, incremental center hole drilling, and neutron diffraction.
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Development and Application of the Contour Method to Determine the Residual Stresses in Thin Laser-Peened Aluminium Alloy Plates
Experimental Mechanics, 2015Co-Authors: M.b. Toparli, Michael E. FitzpatrickAbstract:The Contour Method was applied to obtain residual stress fields in a laser-peened 2.0-mm-thick Al2024-T351 sample. In order to remove the effects of near-surface wire electro-discharge machining (EDM) cutting artefacts on the measured residual stresses, sacrificial blocks were attached to both surfaces of the thin sample with a polymer-based glue doped with silver particles. A data analysis routine based on bivariate spline smoothing was conducted to obtain a 2D residual stress map. The results were compared with incremental hole drilling, and X-ray diffraction and layer removal techniques. The results are in good agreement in terms of the magnitudes and the location of the peak stresses, with the exception of the Contour Method results. Owing to the low thickness of the samples, the data analysis is very sensitive to the parameters used in the spline fitting, leading to fluctuation in the results. It is concluded that the Contour Method can be applied to thin samples, however, extra attention is required. Since the uncertainty is higher compared to the conventional Contour Method results, it is good practice to compare the results with at least one other experimental Method.
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Residual stress measurements on a metal matrix composite using the Contour Method with brittle fracture
Advanced Materials Research, 2014Co-Authors: Jeferson Araujo De Oliveira, Michael E. Fitzpatrick, Jan KowalAbstract:In this work we evaluate the application of the Contour Method to fatigue and fracture surfaces. Residual stress measurements were made on quenched and aged AA2124-SiCp composite using neutron diffraction, the Contour Method with wire EDM, and the Contour Method on a fatigue crack surface including brittle failure. The Contour Method successfully measured residual stresses from a wire electro-discharge cut surface, but the fracture Method results suggest that residual stress information is lost due to plasticity during fatigue crack growth.
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Improvement of the Contour Method for Measurement of Near-Surface Residual Stresses from Laser Peening
Experimental Mechanics, 2013Co-Authors: M.b. Toparli, Michael E. Fitzpatrick, S. GungorAbstract:A study was conducted to develop a Methodology to obtain near-surface residual stresses for laser-peened aluminium alloy samples using the Contour Method. After cutting trials to determine the optimal cut parameters, surface Contours were obtained and a new data analysis Method based on spline smoothing was applied. A new criterion for determining the optimal smoothing parameters is introduced. Near-surface residual stresses obtained from the Contour Method were compared with X-ray diffraction and incremental hole drilling results. It is concluded that with optimal cutting parameters and data analysis, reliable near-surface residual stresses can be obtained by the Contour Method.
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Residual Stress Mapping in Welds Using the Contour Method
Materials Science Forum, 2005Co-Authors: Ying Zhang, S. Pratihar, Michael E. Fitzpatrick, Lyndon EdwardsAbstract:The Contour Method, a newly-invented sectioning technique for residual stress measurement, has the potential to measure the cross-sectional residual stress profile of a weld in a simple and time-efficient manner. In this paper we demonstrate the capability of the Contour Method to measure cross-sectional residual stress profiles, which are compared with neutron diffraction measurements and show excellent agreement. The results provide useful information for safetycritical design of welded components and optimization of welding parameters, and also illustrate the potential of the Contour technique as a powerful tool for residual stress evaluation.
Michael R Hill - One of the best experts on this subject based on the ideXlab platform.
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Repeatability of Contour Method Residual Stress Measurements for a Range of Materials, Processes, and Geometries
Materials Performance and Characterization, 2018Co-Authors: Mitchell D. Olson, Adrian T Dewald, Michael R HillAbstract:This paper examines precision of the Contour Method using five residual stress measurement repeatability studies. The test specimens evaluated include: an aluminum T-section, a stainless steel plate with a dissimilar metal slot-filled weld, a stainless steel forging, a titanium plate with an electron beam slot-filled weld, and a nickel disk forging. These specimens were selected to encompass a range of typical materials and residual stress distributions. Each repeatability study included Contour Method measurements on five to ten similar specimens. Following completion of the residual stress measurements an analysis was performed to determine the repeatability standard deviation of each population. In general, the results of the various repeatability studies are similar. The repeatability standard deviation tends to be relatively small throughout the part interior and there are localized regions of higher repeatability along the part perimeter. The repeatability standard deviations over most of the cross-section range from 5 MPa, for the aluminum T-section, to 35 MPa, for the stainless steel forging. These results provide expected precision data for the Contour Method over a broad range of specimen geometries, materials, and stress profiles.
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Validation of a Contour Method Single-Measurement Uncertainty Estimator
Experimental Mechanics, 2018Co-Authors: Mitchell D. Olson, A. T. Dewald, Michael R HillAbstract:This work validates an analytical single-measurement uncertainty estimator for Contour Method measurement by comparing it with a first-order uncertainty estimate provided by a repeatability study. The validation was performed on five different specimen types. The specimen types cover a range of geometries, materials, and stress conditions that represent typical structural applications. The specimen types include: an aluminum T-section, a stainless steel plate with a dissimilar metal slot-filled weld, a stainless steel forging, a titanium plate with an electron beam slot-filled weld, and a nickel disk forging. For each specimen, the residual stress was measured using the Contour Method on replicate specimens to assess measurement precision. The uncertainty associated with each Contour Method measurement was also calculated using a recently published single-measurement uncertainty estimator. Comparisons were then made between the estimated uncertainty and the demonstrated measurement precision. These results show that the single-measurement analytical uncertainty estimate has good correlation with the demonstrated repeatability. The spatial distributions of estimated uncertainty were found to be similar among the conditions evaluated, with the uncertainty relatively constant in the interior and larger along the boundaries of the measurement plane.
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Assessment of Weld Residual Stress Measurement Precision: Mock-Up Design and Results for the Contour Method
Journal of Nuclear Engineering and Radiation Science, 2015Co-Authors: Mitchell D. Olson, Michael R Hill, Eric Willis, Artie G. Peterson, Vipul I. Patel, Ondrej MuránskyAbstract:Recent experimental work has shown residual stress measurements in welded material to be difficult. To better assess the precision of residual stress measurement techniques, a measurement article was designed to allow repeated measurements of a nominally identical stress field. The measurement article is a long 316L stainless steel plate containing a machine-controlled eight-pass slot weld. Measurements of weld direction residual stress made with the Contour Method found high tensile stress in the weld and heat-affected zone, with a maximum near 450 MPa and compressive stress away from the weld, a typical residual stress profile for constrained welds. The repeatability standard deviation of repeated Contour Method residual stress measurements was found to be less than 20 MPa at most spatial locations away from the boundaries of the plate. The repeatability data in the weld are consistent with those from a previous repeatability experiment using the Contour Method in quenched aluminum bars. A finite-element simulation and neutron diffraction measurements were performed for the same weld and provided results consistent with the Contour Method measurements. Much of the material used in the work remains available for use in assessing other residual stress measurement techniques, or for an interlaboratory reproducibility study of the Contour Method.
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Repeatability of the Contour Method for Residual Stress Measurement
Experimental Mechanics, 2014Co-Authors: Michael R Hill, Mitchell D. OlsonAbstract:This paper describes the results of a residual stress measurement repeatability study using the Contour Method. The test specimen is an aluminum bar (cut from plate), with cross sectional dimensions of 50.8 × 76.2 mm (2″ × 3″) with a length of 609.6 mm (24″). There are two bars, one bar with high residual stresses and one bar with low residual stresses. The high residual stress configuration (±150 MPa) is in a quenched and over-aged condition (Al 7050-T74) and the low residual stress configuration (±20 MPa) is stress relieved by stretching (Al 7050-T7451). Five Contour measurements were performed on each aluminum bar at the mid-length of successively smaller pieces. Typical Contour Method procedures are employed with careful clamping of the specimen, wire electric discharge machining (EDM) for the cut, laser surface profiling of the cut faces, surface profile fitting, and linear elastic stress analysis. The measurement results provide repeatability data for the Contour Method, and the difference in repeatability when measuring high or low magnitude stresses. The results show similar repeatability standard deviation for both samples, being less than 10 MPa over most of the cross section and somewhat larger, around 20 MPa, near the cross section edges. A comparison with published repeatability data for other residual stress measurement techniques (x-ray diffraction, incremental hole drilling, and slitting) shows that the Contour Method has a level of repeatability that is similar to, or better than, other techniques.
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measurement of welding residual stress in dissimilar metal welds using the Contour Method
ASME 2011 Pressure Vessels and Piping Conference, 2011Co-Authors: Adrian T Dewald, Michael R Hill, Eric WillisAbstract:Welding residual stresses can significantly impact the performance of structural components. Tensile residual stresses are of particular concern due to their ability to cause significant degradation to the PWSCC resistance of structural materials. The Contour Method is a residual stress measurement technique capable of generating two dimensional maps of residual stress, which is particularly useful when applied to welds due to the complex residual stress distributions that generally result. The two-dimensional capability of the Contour Method enables detailed visualization of complex weld residual stress fields. This data can be used to identify locations and magnitude of tensile residual stress hot-spots. This paper provides a summary of the Contour Method and presents detailed results of Contour Method measurements made on the dissimilar metal weld region of pressurizer relief nozzles removed from the cancelled WNP-3 plant in the United States as part of the NRC/EPRI weld residual stress (WRS) program [1].© 2011 ASME
Mitchell D. Olson - One of the best experts on this subject based on the ideXlab platform.
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Repeatability of Contour Method Residual Stress Measurements for a Range of Materials, Processes, and Geometries
Materials Performance and Characterization, 2018Co-Authors: Mitchell D. Olson, Adrian T Dewald, Michael R HillAbstract:This paper examines precision of the Contour Method using five residual stress measurement repeatability studies. The test specimens evaluated include: an aluminum T-section, a stainless steel plate with a dissimilar metal slot-filled weld, a stainless steel forging, a titanium plate with an electron beam slot-filled weld, and a nickel disk forging. These specimens were selected to encompass a range of typical materials and residual stress distributions. Each repeatability study included Contour Method measurements on five to ten similar specimens. Following completion of the residual stress measurements an analysis was performed to determine the repeatability standard deviation of each population. In general, the results of the various repeatability studies are similar. The repeatability standard deviation tends to be relatively small throughout the part interior and there are localized regions of higher repeatability along the part perimeter. The repeatability standard deviations over most of the cross-section range from 5 MPa, for the aluminum T-section, to 35 MPa, for the stainless steel forging. These results provide expected precision data for the Contour Method over a broad range of specimen geometries, materials, and stress profiles.
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Validation of a Contour Method Single-Measurement Uncertainty Estimator
Experimental Mechanics, 2018Co-Authors: Mitchell D. Olson, A. T. Dewald, Michael R HillAbstract:This work validates an analytical single-measurement uncertainty estimator for Contour Method measurement by comparing it with a first-order uncertainty estimate provided by a repeatability study. The validation was performed on five different specimen types. The specimen types cover a range of geometries, materials, and stress conditions that represent typical structural applications. The specimen types include: an aluminum T-section, a stainless steel plate with a dissimilar metal slot-filled weld, a stainless steel forging, a titanium plate with an electron beam slot-filled weld, and a nickel disk forging. For each specimen, the residual stress was measured using the Contour Method on replicate specimens to assess measurement precision. The uncertainty associated with each Contour Method measurement was also calculated using a recently published single-measurement uncertainty estimator. Comparisons were then made between the estimated uncertainty and the demonstrated measurement precision. These results show that the single-measurement analytical uncertainty estimate has good correlation with the demonstrated repeatability. The spatial distributions of estimated uncertainty were found to be similar among the conditions evaluated, with the uncertainty relatively constant in the interior and larger along the boundaries of the measurement plane.
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Assessment of Weld Residual Stress Measurement Precision: Mock-Up Design and Results for the Contour Method
Journal of Nuclear Engineering and Radiation Science, 2015Co-Authors: Mitchell D. Olson, Michael R Hill, Eric Willis, Artie G. Peterson, Vipul I. Patel, Ondrej MuránskyAbstract:Recent experimental work has shown residual stress measurements in welded material to be difficult. To better assess the precision of residual stress measurement techniques, a measurement article was designed to allow repeated measurements of a nominally identical stress field. The measurement article is a long 316L stainless steel plate containing a machine-controlled eight-pass slot weld. Measurements of weld direction residual stress made with the Contour Method found high tensile stress in the weld and heat-affected zone, with a maximum near 450 MPa and compressive stress away from the weld, a typical residual stress profile for constrained welds. The repeatability standard deviation of repeated Contour Method residual stress measurements was found to be less than 20 MPa at most spatial locations away from the boundaries of the plate. The repeatability data in the weld are consistent with those from a previous repeatability experiment using the Contour Method in quenched aluminum bars. A finite-element simulation and neutron diffraction measurements were performed for the same weld and provided results consistent with the Contour Method measurements. Much of the material used in the work remains available for use in assessing other residual stress measurement techniques, or for an interlaboratory reproducibility study of the Contour Method.
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Estimation of Uncertainty for Contour Method Residual Stress Measurements
Experimental Mechanics, 2015Co-Authors: Mitchell D. Olson, A. T. Dewald, M. B. Prime, M. R. HillAbstract:This paper describes a Methodology for the estimation of measurement uncertainty for the Contour Method, where the Contour Method is an experimental technique for measuring a two-dimensional map of residual stress over a plane. Random error sources including the error arising from noise in displacement measurements and the smoothing of the displacement surfaces are accounted for in the uncertainty analysis. The output is a two-dimensional, spatially varying uncertainty estimate such that every point on the cross-section where residual stress is determined has a corresponding uncertainty value. Both numerical and physical experiments are reported, which are used to support the usefulness of the proposed uncertainty estimator. The uncertainty estimator shows the Contour Method to have larger uncertainty near the perimeter of the measurement plane. For the experiments, which were performed on a quenched aluminum bar with a cross section of 51 × 76 mm, the estimated uncertainty was approximately 5 MPa (σ/E = 7 · 10^−5) over the majority of the cross-section, with localized areas of higher uncertainty, up to 10 MPa (σ/E = 14 · 10^−5).
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Repeatability of the Contour Method for Residual Stress Measurement
Experimental Mechanics, 2014Co-Authors: Michael R Hill, Mitchell D. OlsonAbstract:This paper describes the results of a residual stress measurement repeatability study using the Contour Method. The test specimen is an aluminum bar (cut from plate), with cross sectional dimensions of 50.8 × 76.2 mm (2″ × 3″) with a length of 609.6 mm (24″). There are two bars, one bar with high residual stresses and one bar with low residual stresses. The high residual stress configuration (±150 MPa) is in a quenched and over-aged condition (Al 7050-T74) and the low residual stress configuration (±20 MPa) is stress relieved by stretching (Al 7050-T7451). Five Contour measurements were performed on each aluminum bar at the mid-length of successively smaller pieces. Typical Contour Method procedures are employed with careful clamping of the specimen, wire electric discharge machining (EDM) for the cut, laser surface profiling of the cut faces, surface profile fitting, and linear elastic stress analysis. The measurement results provide repeatability data for the Contour Method, and the difference in repeatability when measuring high or low magnitude stresses. The results show similar repeatability standard deviation for both samples, being less than 10 MPa over most of the cross section and somewhat larger, around 20 MPa, near the cross section edges. A comparison with published repeatability data for other residual stress measurement techniques (x-ray diffraction, incremental hole drilling, and slitting) shows that the Contour Method has a level of repeatability that is similar to, or better than, other techniques.
Foroogh Hosseinzadeh - One of the best experts on this subject based on the ideXlab platform.
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The incremental Contour Method using asymmetric stiffness cuts
Materials & Design, 2021Co-Authors: Anas Achouri, Foroogh Hosseinzadeh, P. John Bouchard, Sanjooram Paddea, Ondrej MuránskyAbstract:Abstract An incremental Contour Method (iCM) of residual stress measurement is proposed where residual stresses in the body of interest are sequentially reduced by successive Contour cuts and the risk of stress re-distribution plasticity is mitigated or eliminated. The cutting-induced plasticity is known to cause significant inaccuracies when trying to measure the near-yield residual stresses using a conventional single cut Contour Method. The iCM procedure implements a new displacement data processing approach for the general case of sectioning at an arbitrary plane where the cut parts do not possess mirror-symmetric elastic stiffness. The basis for the new asymmetric stiffness data analysis approach is presented and the accuracy of the new Method demonstrated using both numerical and experimental case studies.
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residual stress measurements in offshore wind monopile weldments using neutron diffraction technique and Contour Method
Theoretical and Applied Fracture Mechanics, 2018Co-Authors: Anais Jacob, Foroogh Hosseinzadeh, Ali Mehmanparast, Jeferson Araujo De Oliveira, Joe Kelleher, Filippo BertoAbstract:Abstract Reliable assessment of the fatigue life of offshore wind monopiles operating in harsh offshore environments relies on quantifying the level of residual stresses locked-in at circumferential weld regions. This study presents, for the first time, residual stress characterisation, using the Contour Method, on a large structural welded mock-up, typical of the weldment used in offshore wind monopiles. The Contour Method and neutron diffraction measurements were also conducted on a compact tension specimen extracted from the large mock-up. The extracted compact tension sample, typically used for fracture and fatigue crack growth tests, showed notably significant remnant residual stresses that could impact fracture and fatigue test results. In addition the measured 2D map of transverse residual stresses, acting normal to the crack plane, playing a key role in fatigue crack opening/closure, exhibited variations through the thickness of the compact tension sample. The key conclusion was that the residual stresses in small laboratory samples extracted from large scale weldments should be carefully characterised and taken into account in structural integrity tests. Besides, the measurement results on the welded mock-up showed that the level of damaging tensile residual stress in large-scale mock-ups and hence real size structural welded monopiles is considerably larger than residual stresses in extracted laboratory samples; hence will have more significant influence on structural integrity of offshore wind assets.
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Investigating optimal cutting configurations for the Contour Method of weld residual stress measurement
International Journal of Pressure Vessels and Piping, 2018Co-Authors: Ondrej Muránsky, Foroogh Hosseinzadeh, Cory J. Hamelin, Yeli Traore, P J BendeichAbstract:The present work examines optimal cutting configurations for the measurement of weld residual stresses (WRS) using the Contour Method. The accuracy of a conventional, single-cut configuration that employs rigid clamping is compared with novel, double-embedded cutting configurations that rely on specimen self-constraint during cutting. Numerical analyses examine the redistribution of WRS and the development of cutting-induced plasticity (CIP) in a three-pass austenitic slot weld (NeT TG4) during the cutting procedure for each configuration. Stress intensity factor (SIF) analyses are first used as a screening tool; these analyses characterise lower stress intensities near the cutting surface when double-embedded cutting configurations are used, relative to SIF profiles from a single-cut process. The lower stress intensities indicate the development of CIP – which will ultimately affect back-calculated WRS – is less likely to occur when using an embedded configuration. The improvements observed for embedded cutting approaches are confirmed using three-dimensional finite element (FE) cutting simulations. The simulations reveal significant localised plasticity that forms in the material ligaments located between the pilot holes and the outer edges of the specimen. This plasticity is caused by WRS redistribution during the cutting process. The compressive plasticity in these material ligaments is shown to reduce the overall tensile WRS near the weld region before this region is sectioned, thereby significantly reducing the amount of CIP when cutting through the weld region at a later stage of the cutting procedure. Further improvements to the embedded cutting configuration are observed when the equilibrating compressive stresses in material ligaments are removed entirely (via sectioning) prior to sectioning of the high WRS region in the vicinity of the weld. All numerical results are validated against a series of WRS measurements performed using the Contour Method on a set of NeT TG4 benchmark weld specimens.
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Asymmetric Cuts In The Contour Method For Residual Stress Measurement
2017Co-Authors: Anas Achouri, P. John Bouchard, S. Kabra, Foroogh HosseinzadehAbstract:The standard Contour Method is limited to sectioning test components into two symmetric halves. In this study a new approach is developed to deal with asymmetric cuts in the Contour Method of residual stress measurement. The proposed approach is demonstrated using finite element (FE) simulations and is validated experimentally using a series of asymmetric Contour cuts and neutron diffraction measurements.
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towards good practice guidelines for the Contour Method of residual stress measurement
The Journal of Engineering, 2014Co-Authors: Foroogh Hosseinzadeh, Jan Kowal, P. J. BouchardAbstract:Accurate measurement of residual stress in metallic components using the Contour Method relies on the achievement of a good quality cut, on the appropriate measurement of the deformed cut surface and on the robust analysis of the measured data. There is currently no published standard or code of practice for the Contour Method. As a first step towards such a standard, this study draws on research investigations addressing the three main steps in the Method: how best to cut the specimens; how to measure the deformation Contour of the cut surface; and how to analyse the data. Good practice guidance is provided throughout the text accompanied by more detailed observations and advice tabulated in Appendix.
Ondrej Muránsky - One of the best experts on this subject based on the ideXlab platform.
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The incremental Contour Method using asymmetric stiffness cuts
Materials & Design, 2021Co-Authors: Anas Achouri, Foroogh Hosseinzadeh, P. John Bouchard, Sanjooram Paddea, Ondrej MuránskyAbstract:Abstract An incremental Contour Method (iCM) of residual stress measurement is proposed where residual stresses in the body of interest are sequentially reduced by successive Contour cuts and the risk of stress re-distribution plasticity is mitigated or eliminated. The cutting-induced plasticity is known to cause significant inaccuracies when trying to measure the near-yield residual stresses using a conventional single cut Contour Method. The iCM procedure implements a new displacement data processing approach for the general case of sectioning at an arbitrary plane where the cut parts do not possess mirror-symmetric elastic stiffness. The basis for the new asymmetric stiffness data analysis approach is presented and the accuracy of the new Method demonstrated using both numerical and experimental case studies.
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Investigating optimal cutting configurations for the Contour Method of weld residual stress measurement
International Journal of Pressure Vessels and Piping, 2018Co-Authors: Ondrej Muránsky, Foroogh Hosseinzadeh, Cory J. Hamelin, Yeli Traore, P J BendeichAbstract:The present work examines optimal cutting configurations for the measurement of weld residual stresses (WRS) using the Contour Method. The accuracy of a conventional, single-cut configuration that employs rigid clamping is compared with novel, double-embedded cutting configurations that rely on specimen self-constraint during cutting. Numerical analyses examine the redistribution of WRS and the development of cutting-induced plasticity (CIP) in a three-pass austenitic slot weld (NeT TG4) during the cutting procedure for each configuration. Stress intensity factor (SIF) analyses are first used as a screening tool; these analyses characterise lower stress intensities near the cutting surface when double-embedded cutting configurations are used, relative to SIF profiles from a single-cut process. The lower stress intensities indicate the development of CIP – which will ultimately affect back-calculated WRS – is less likely to occur when using an embedded configuration. The improvements observed for embedded cutting approaches are confirmed using three-dimensional finite element (FE) cutting simulations. The simulations reveal significant localised plasticity that forms in the material ligaments located between the pilot holes and the outer edges of the specimen. This plasticity is caused by WRS redistribution during the cutting process. The compressive plasticity in these material ligaments is shown to reduce the overall tensile WRS near the weld region before this region is sectioned, thereby significantly reducing the amount of CIP when cutting through the weld region at a later stage of the cutting procedure. Further improvements to the embedded cutting configuration are observed when the equilibrating compressive stresses in material ligaments are removed entirely (via sectioning) prior to sectioning of the high WRS region in the vicinity of the weld. All numerical results are validated against a series of WRS measurements performed using the Contour Method on a set of NeT TG4 benchmark weld specimens.
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Assessment of Weld Residual Stress Measurement Precision: Mock-Up Design and Results for the Contour Method
Journal of Nuclear Engineering and Radiation Science, 2015Co-Authors: Mitchell D. Olson, Michael R Hill, Eric Willis, Artie G. Peterson, Vipul I. Patel, Ondrej MuránskyAbstract:Recent experimental work has shown residual stress measurements in welded material to be difficult. To better assess the precision of residual stress measurement techniques, a measurement article was designed to allow repeated measurements of a nominally identical stress field. The measurement article is a long 316L stainless steel plate containing a machine-controlled eight-pass slot weld. Measurements of weld direction residual stress made with the Contour Method found high tensile stress in the weld and heat-affected zone, with a maximum near 450 MPa and compressive stress away from the weld, a typical residual stress profile for constrained welds. The repeatability standard deviation of repeated Contour Method residual stress measurements was found to be less than 20 MPa at most spatial locations away from the boundaries of the plate. The repeatability data in the weld are consistent with those from a previous repeatability experiment using the Contour Method in quenched aluminum bars. A finite-element simulation and neutron diffraction measurements were performed for the same weld and provided results consistent with the Contour Method measurements. Much of the material used in the work remains available for use in assessing other residual stress measurement techniques, or for an interlaboratory reproducibility study of the Contour Method.