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

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.

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Residual Stress Measurement in a Ceramic-Metallic Graded Material

Journal of Engineering Materials and Technology ◽

10.1115/1.1446073 ◽

2002 ◽

Vol 124 (2) ◽

pp. 185-191 ◽

Cited By ~ 37

Author(s):

Michael R. Hill ◽

Wei-Yan Lin

Keyword(s):

Residual Stress ◽

Finite Element ◽

Error Analysis ◽

Residual Stresses ◽

Stress Measurement ◽

Pure Titanium ◽

Titanium Boride ◽

Residual Stress Measurement ◽

Graded Material ◽

Strain Release

This paper presents experimental measurements of the through-thickness distribution of residual stress in a ceramic-metallic functionally graded material (FGM). It further presents an error analysis and optimization of the residual stress measurement technique. Measurements are made in a seven-layered plate with a base of commercially pure titanium and successive layers containing an increasing proportion of titanium-boride, reaching 85% titanium-boride in the final layer. The compliance method is employed to determine residual stress, where a slot is introduced using wire electric-discharge machining and strain release is measured as a function of increasing slot depth. Strain release measurements are used with a back-calculation scheme, based on finite element simulation, to provide residual stresses in the FGM. The analysis is complicated by the variation of material properties in the FGM, but tractable due to the flexibility of the finite element method. The Monte Carlo approach is used for error analysis and a method is described for optimization of the functional form assumed for the residual stresses. The magnitude and variation of the resulting residual stress distributions and several aspects of the error analyses are discussed.

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Residual Stress Measurement of Full-Scale Jet-Engine Bearing Elements Using the Contour Method

Residual Stress, Thermomechanics & Infrared Imaging, Hybrid Techniques and Inverse Problems, Volume 9 - Conference Proceedings of the Society for Experimental Mechanics Series ◽

10.1007/978-3-319-42255-8_10 ◽

2016 ◽

pp. 69-81

Author(s):

Daulton D. Isaac ◽

Michael B. Prime ◽

Nagaraj Arakere

Keyword(s):

Residual Stress ◽

Stress Measurement ◽

Full Scale ◽

Residual Stress Measurement ◽

Contour Method ◽

Jet Engine ◽

Engine Bearing

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Investigation of the Performance of the Contour Residual Stress Measurement Method When Applied to Welded Pipe Structures

Volume 6: Materials and Fabrication, Parts A and B ◽

10.1115/pvp2009-77470 ◽

2009 ◽

Cited By ~ 3

Author(s):

R. J. Dennis ◽

N. A. Leggatt ◽

E. A. Kutarski

Keyword(s):

Residual Stress ◽

Residual Stresses ◽

Measurement Method ◽

Stress Measurement ◽

Complex Structure ◽

Cutting Process ◽

Residual Stress Measurement ◽

Contour Method ◽

Hole Drilling ◽

Welded Pipe

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 the cutting process and the influence that they have on the measured residual stresses. Both of these aspects have been investigated in previous work by simulating the entire contour measurement method process using finite element techniques for ‘simple’ flat plate welded specimens. Here that work is further investigated and extended by application to a 316 Stainless Steel welded pipe structure containing a part-circumferential repair. This more complex structure and residual stress field is of significantly greater engineering interest. The key objective of this work is to ascertain the feasibility of and further our understanding of the performance of the Contour Method. Furthermore this work has the potential to provide a method to support the optimisation of the contour measurement process when applied to more complex engineering components.

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

Materials Science Forum ◽

10.4028/www.scientific.net/msf.524-525.671 ◽

2006 ◽

Vol 524-525 ◽

pp. 671-676 ◽

Cited By ~ 18

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.

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

Journal of Pressure Vessel Technology ◽

10.1115/1.4004626 ◽

2011 ◽

Vol 134 (1) ◽

Cited By ~ 21

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.

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

ASME 2010 Pressure Vessels and Piping Conference: Volume 6, Parts A and B ◽

10.1115/pvp2010-25690 ◽

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.

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

Volume 3: Structures, Safety, and Reliability ◽

10.1115/omae2018-78519 ◽

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.

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New UK Research Programme on Residual Stresses

Volume 6: Materials and Fabrication ◽

10.1115/pvp2006-icpvt-11-93567 ◽

2006 ◽

Cited By ~ 3

Author(s):

Steve K. Bate ◽

Chris Watson

Keyword(s):

Residual Stress ◽

Finite Element ◽

Residual Stresses ◽

Structural Integrity ◽

Stress Measurement ◽

Research Work ◽

Research Programme ◽

Residual Stress Measurement ◽

Engineering Structures ◽

The Uk

A new long-term research programme has been launched in the UK. This involves Rolls-Royce plc and Serco Assurance, supported by UK industry and academia. A significant part of this programme is aimed at progressing the understanding of weld residual stresses and the implementation of finite element simulation and residual stress measurement for assessing the structural integrity of engineering structures and components. The work includes: (1) Finite element modelling to investigate heat source representation, material behaviour and 3D v 2D effects. (2) Design and manufacture of mock-ups for supporting validation. (3) Residual stress measurement. (4) Weld design. (5) Residual stress profiles. (6) Material testing. (7) Development of a procedure for residual stress modelling. The work is being undertaken by a combination of finite element analyses and residual stress measurement using a variety of techniques. This paper presents an overview of the research work being undertaken and provides examples of the outcome of some of the studies obtained to-date.

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Finite Element Validation of the over-Coring Deep-Hole Drilling Technique

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.70.291 ◽

2011 ◽

Vol 70 ◽

pp. 291-296 ◽

Cited By ~ 4

Author(s):

Sayeed Hossain ◽

Ed J. Kingston ◽

Christopher E. Truman ◽

David John Smith

Keyword(s):

Residual Stress ◽

Finite Element ◽

Stress Field ◽

Residual Stresses ◽

Stress Measurement ◽

Residual Stress Measurement ◽

Hole Drilling ◽

Deep Hole ◽

Residual Stress Field ◽

Deep Hole Drilling

The main objective of the present study is to validate a simple over-coring deep-hole drilling (oDHD) residual stress measurement technique by utilising finite element simulations of the technique. A number of three dimensional (3D) finite element analyses (FEA) were carried out to explore the influence of material removal and the cutting sequence during the deep-hole drilling (DHD) residual stress measurement process on the initial residual stress field. Two models were considered in the study. First, the residual stress field predicted in a rapid spray water quenched solid cylinder was used as the initial stress field for the DHD FE model. The DHD reconstructed residual stresses were compared with the initial FE predicted stresses. Different cutting sequences and different dimensions were systematically simulated before arriving at an optimum solution for the oDHD technique. The oDHD technique significantly improved the spatial resolution and was applied in a second model consisting of a 40mm thick butt-welded pipe. The DHD reconstructed residual stresses compared very well with the initial FE predicted weld residual stress thereby validating the oDHD technique.

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