Cross-sectional Mapping of Residual Stresses Using the Contour Method

2019 ◽  
Vol 88 (6) ◽  
pp. 472-475
Author(s):  
Daisuke TAKAKURA ◽  
Hiroshi FUKAZAWA ◽  
Mitsuyoshi TSUNORI
2000 ◽  
Vol 123 (2) ◽  
pp. 162-168 ◽  
Author(s):  
M. B. Prime

A powerful new method for residual stress measurement is presented. A part is cut in two, and the contour, or profile, of the resulting new surface is measured to determine the displacements caused by release of the residual stresses. Analytically, for example using a finite element model, the opposite of the measured contour is applied to the surface as a displacement boundary condition. By Bueckner’s superposition principle, this calculation gives the original residual stresses normal to the plane of the cut. This “contour method” is more powerful than other relaxation methods because it can determine an arbitrary cross-sectional area map of residual stress, yet more simple because the stresses can be determined directly from the data without a tedious inversion technique. The new method is verified with a numerical simulation, then experimentally validated on a steel beam with a known residual stress profile.


Author(s):  
Foroogh Hosseinzadeh ◽  
P. John Bouchard

The work presented in this paper explores the through-thickness distribution of residual stresses in a valve seat of complex geometry where a Tristelle insert was HIP-bonded to a Type 316 stainless steel body. The contour method was conducted in a novel way to measure a full cross-sectional map of hoop stress at an axial-radial plane along the length of the valve seat. Special care was applied to control and optimise the cutting step of the measurement technique in order to produce cut surfaces of high quality thereby minimising potential associated errors in stress. The innovation in the present work was to use sacrificial material to avoid any cutting artefacts introduced by the cutting process. High levels of residual stresses were measured in the region where an insert was HIP-bonded to the main body. The excellent correlation between the stresses measured using the contour and incremental centre hole drilling methods demonstrates the importance of controlling the quality of a contour cut and that care should be taken to avoid cutting artefacts particularly when stresses close to the surface are of interest.


2004 ◽  
Vol 52 (17) ◽  
pp. 5225-5232 ◽  
Author(s):  
Y. Zhang ◽  
S. Ganguly ◽  
L. Edwards ◽  
M.E. Fitzpatrick

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1298
Author(s):  
Shuyan Zhang ◽  
Zhuozhi Fan ◽  
Jun Li ◽  
Shuwen Wen ◽  
Sanjooram Paddea ◽  
...  

In this study, a mock-up of a nuclear safe-end dissimilar metal weld (DMW) joint (SA508-3/316L) was manufactured. The manufacturing process involved cladding and buttering of the ferritic steel tube (SA508-3). It was then subjected to a stress relief heat treatment before being girth welded together with the stainless steel tube (316L). The finished mock-up was subsequently machined to its final dimension. The weld residual stresses were thoroughly characterised using neutron diffraction and the contour method. A detailed finite element (FE) modelling exercise was also carried out for the prediction of the weld residual stresses resulting from the manufacturing processes of the DMW joint. Both the experimental and numerical results showed high levels of tensile residual stresses predominantly in the hoop direction of the weld joint in its final machined condition, tending towards the OD surface. The maximum hoop residual stress determined by the contour method was 500 MPa, which compared very well with the FE prediction of 467.7 Mpa. Along the neutron scan line at the OD subsurface across the weld joint, both the contour method and the FE modelling gave maximum hoop residual stress near the weld fusion line on the 316L side at 388.2 and 453.2 Mpa respectively, whereas the neutron diffraction measured a similar value of 480.6 Mpa in the buttering zone near the SA508-3 side. The results of this research thus demonstrated the reasonable consistency of the three techniques employed in revealing the level and distribution of the residual stresses in the DMW joint for nuclear applications.


2013 ◽  
Vol 7 (1) ◽  
pp. 18-26 ◽  
Author(s):  
Pierpaolo Carlone ◽  
Gaetano S. Palazzo

Friction Stir Welding (FSW) is an innovative solid-state joining process, which is gaining a great deal of attention in several applicative sectors. The opportune definition of process parameters, i.e. minimizing residual stresses, is crucial to improve joint reliability in terms of static and dynamic performance. Longitudinal residual stresses, induced by FSW in AA2024-T3 butt joints, have been inferred by means of a recently developed technique, namely the contour method. Two approaches to stress measurement have been adopted; the former is based on the assumption of uniform material properties, the latter takes into account microstructural effects and material properties variations in the welding zones. The influence of process parameters, namely rotating and welding speeds, on stress distribution is also discussed.


2014 ◽  
Vol 996 ◽  
pp. 755-760 ◽  
Author(s):  
Bilal Ahmad ◽  
Michael E. Fitzpatrick

Fatigue cracks mostly initiate at areas subjected to high tensile residual stress and stress concentration. Ultrasonic peening is a mechanical method to increase fatigue life by imparting compressive residual stress. In this study residual stresses are characterized in fillet welded ship structural steel plates with longitudinal attachments. As-welded, ultrasonically peened, and specimens peened then subjected to accelerated corrosion testing were measured. Residual stress characterization was performed by the contour method and neutron diffraction.


2019 ◽  
Vol 799 ◽  
pp. 20-25
Author(s):  
Harri Lille ◽  
Alexander Ryabchikov ◽  
Jakub Kõo ◽  
Valdek Mikli ◽  
Eron Adoberg ◽  
...  

In this study we determined average residual stresses in hard nitride PVD AlCrN, TiAlN and TiCN coatings through simultaneous measurement of length variation in thin-walled tubular substrates and of the curvature of plate substrates. A device for measurement of the length of the tube was developed. Inside the depositing chamber the tube and the plate were fixed parallel in the relation to the axis of the rotating cathode. One batch of plate samples was produced by deposition on front surface (facing the cathode) and the other batch, by deposition on back surface (with back to the cathode). The cross-sectional microstructure and thickness of the coatings were investigated by means of scanning electron microscopy (SEM). The thicknesses of the coatings deposited on front and back surfaces of the plates and on the tube were significantly different. The values of average compressive residual stresses, determined by both methods, were very high irrespective of coating thickness. It was found that the values of compressive residual stresses in the coating were dependent on the shape of the substrate and on its position in the relation to the axis of the rotating cathode.


2018 ◽  
Vol 941 ◽  
pp. 269-273
Author(s):  
Constant Ramard ◽  
Denis Carron ◽  
Philippe Pilvin ◽  
Florent Bridier

Multipass arc welding is commonly used for thick plates assemblies in shipbuilding. Sever thermal cycles induced by the process generate inhomogeneous plastic deformation and residual stresses. Metallurgical transformations contribute at each pass to the residual stress evolution. Since residual stresses can be detrimental to the performance of the welded product, their estimation is essential and numerical modelling is useful to predict them. Finite element analysis of multipass welding of a high strength steel is achieved with a special emphasis on mechanical and metallurgical effects on residual stress. A welding mock-up was specially designed for experimental measurements of in-depth residual stresses using contour method and deep hole drilling and to provide a simplified case for simulation. The computed results are discussed through a comparison with experimental measurements.


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