Through-thickness distributions of residual stresses in two extreme heat-input thick welds: A neutron diffraction, contour method and deep hole drilling study

2013 ◽  
Vol 61 (10) ◽  
pp. 3564-3574 ◽  
Author(s):  
W. Woo ◽  
G.B. An ◽  
E.J. Kingston ◽  
A.T. DeWald ◽  
D.J. Smith ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Residual Stresses ◽  
Heat Input ◽  
Extreme Heat ◽  
Contour Method ◽  
Hole Drilling ◽  
Deep Hole ◽  
Deep Hole Drilling

Residual Stress Measurements Using the Contour, Deep-Hole Drilling and Neutron Diffraction Methods in T-Section Specimens

2016 ◽  
Author(s):  
Karim Serasli ◽  
Douglas Cave ◽  
Ed Kingston
Keyword(s):  
Residual Stress ◽  
Neutron Diffraction ◽  
Residual Stresses ◽  
Complex Geometry ◽  
Contour Method ◽  
Hole Drilling ◽  
Deep Hole ◽  
Premature Failure ◽  
Deep Hole Drilling ◽  
The Wire

The presence of high magnitude residual stresses in welded components causes material degradation, local yielding and plastic deformation. Their presence provides the potential for premature failure and compromises the integrity of a structure. This paper presents a review of work carried out to ascertain the residual stresses present within T-section specimens, made from ferritic steel, in their as-welded condition. The standard and incremental deep hole drilling (DHD and iDHD) techniques, the neutron diffraction (ND) and the contour method were applied to characterise the residual stresses in the regions in and around the two fillet welds of the specimens and the surrounding parent material within which the balancing residual stresses needed to be measured. The results of these measurements are presented and compared to highlight agreements and discrepancies in the measured residual stress distributions using these different techniques. A compendium of measurements at a similar location in various T-sections and their comparison with the BS7910 standard show that the measured longitudinal distributions are similar despite the observed scatter. Finally, this paper briefly attempts to investigate and discuss the technical challenges identified when applying the contour method to complex geometry components. The constraint of the specimen during the wire electro-discharge machining (EDM) process, the quality of the wire EDM cut made and the analysis of the raw data for the conversion into residual stresses directly affect the accuracy of the contour method results. The identification and investigation of these challenges lead to continuous improvements of the contour method procedure and reduce uncertainties of the measurement.

Simulation and Measurement of Residual Stresses in a Stainless Steel Ring Welded Circular Disc

2012 ◽  
Author(s):  
Gang Zheng ◽  
Sayeed Hossain ◽  
Mike Smith ◽  
David Smith
Keyword(s):  
Residual Stress ◽  
Neutron Diffraction ◽  
Residual Stresses ◽  
Stress Measurement ◽  
Circular Disc ◽  
Hole Drilling ◽  
Deep Hole ◽  
Deep Hole Drilling ◽  
Hole Drilling Method ◽  
Drilling Method

Residual stresses were predicted and measured in a circular disc containing a partial ring weld. This study first created an axisymmetric finite element model so that the process of introducing the ring weld was simulated using thermal and mechanical modelling. The resulting residual stresses were then mapped onto a 3D model which included the necessary mesh and boundary conditions to simulate the process of residual stress measurement using the deep hole drilling method. Then an experimental programme of residual stress measurement using the deep hole drilling method and the neutron diffraction technique was conducted on the welded circular disc. The results from the deep hole drilling measurements matched well with the neutron diffraction results on the original stress field in the ring weld. While comparison between measurements and predicted residual stresses show that predicted hoop stresses are slightly higher than measured, there is in general a fair comparison between measured and predicted residual stress.

A Procedure to Measure Biaxial Near Yield Residual Stresses Using the Deep Hole Drilling Technique

2013 ◽  
Vol 53 (7) ◽  
pp. 1223-1231 ◽  
Author(s):  
A. H. Mahmoudi ◽  
G. Zheng ◽  
D. J. Smith ◽  
C. E. Truman ◽  
M. J. Pavier
Keyword(s):  
Residual Stresses ◽  
Hole Drilling ◽  
Deep Hole ◽  
Deep Hole Drilling ◽  
Drilling Technique

Analysis and Optimization of the Deep-Hole Drilling Technique in Measuring Complex Residual Stress

2017 ◽  
Author(s):  
Gang Zheng ◽  
Sayeed Hossain ◽  
Feng Shen ◽  
Chris Truman
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Longitudinal Axis ◽  
Hole Drilling ◽  
Internal Diameter ◽  
Deep Hole ◽  
Element Analysis ◽  
Deep Hole Drilling ◽  
Drilling Technique ◽  
Technique Comparison

The aim of the present study was to utilize a complex residual stress generated within a welded circular disc to further investigate the standard deep-hole drilling (DHD) technique and the newly developed over-coring deep-hole drilling (oDHD) technique in accurately measuring residual stresses well over yield stress. Finite Element Analysis (FEA) was used to optimize and extend the deep-hole drilling technique and improve its accuracy. The standard DHD procedure involves 4 steps. (1) A reference hole is gun-drilled through the component. (2) The internal diameter of the reference hole is measured at different angular positions through the depth of the component. (3) A cylindrical section with the reference hole as its longitudinal axis is trepanned free from the component. (4) Finally, the relaxed internal diameter is re-measured at the same angular positions and the same depths. The drilling, trepanning procedures and the parameters of the deep-hole drilling technique were all studied in detail to optimize the technique. Comparison is made between the FEA predicted residual stress in the weld, the measurements and the reconstructed residual stresses of the measurements. The close correlations confirmed the suitability of new modifications made in the deep-hole drilling technique to account for plasticity when measuring near yield residual stresses present in a component.

Uncertainty in Residual Stress Measurements

2008 ◽  
Author(s):  
D. M. Goudar ◽  
S. Hossain ◽  
C. E. Truman ◽  
D. J. Smith
Keyword(s):  
Residual Stress ◽  
Neutron Diffraction ◽  
Measurement Techniques ◽  
Diffraction Method ◽  
Hole Drilling ◽  
Invasive Technique ◽  
Deep Hole ◽  
Deep Hole Drilling ◽  
Integrity Assessment ◽  
Path Lengths

Accurate characterization of residual stress in engineering components is important in structural integrity assessment. Two commonly used methods of measuring residual stress include the neutron diffraction technique and the deep-hole drilling (DHD) technique. The former is a well-known nondestructive measurement method and the latter is a semi-invasive technique which is readily available and portable. Both these measurement techniques depend on a number of physical quantities and are therefore sensitive to errors associated with the measured data. The resulting stress uncertainties can easily become significant and compromise the usefulness of the results or lead to misinterpretation of the behaviour of stress distribution. This paper describes briefly the error analysis for both techniques. Results from earlier neutron diffraction and deep hole drilling measurements are used to illustrate the errors. It is found that the average error for both techniques is about ±20MPa. In the case of the neutron diffraction method this error is acceptable for path lengths less than a few centimetres. At greater path lengths the errors become unacceptably large. In contrast the error in the DHD is independent of depth.

Residual Stress Investigation in a Stainless Steel Ring Welded Circular Disc by Over-Coring Deep Hole Drilling Simulation and Measurement

2014 ◽  
Author(s):  
Gang Zheng ◽  
Sayeed Hossain ◽  
Mike C. Smith ◽  
David J. Smith
Keyword(s):  
Residual Stress ◽  
Neutron Diffraction ◽  
Stress Measurement ◽  
Circular Disc ◽  
Residual Stress Measurement ◽  
Hole Drilling ◽  
Deep Hole ◽  
Deep Hole Drilling ◽  
Welding Simulation ◽  
Drilling Simulation

A circular disc containing a partial ring weld has been devised to permit high levels of residual stress to be created in a relatively small specimen. The purpose of this research is to investigate the residual stress within the weld whilst developing a residual stress measurement method called the over-coring deep hole drilling (oDHD) method. The welding simulation, incremental deep hole drilling (iDHD) simulation and measurement and neutron diffraction were previously studied and reported in [1]. In this paper, the welding simulation results were mapped into a 3D model that included the necessary mesh and boundary conditions to simulate the process of residual measurement using the oDHD method. An experimental programme of residual stress measurement using the oDHD method was then conducted on a welded circular disc. The results from the oDHD simulation and measurement matched well with previous iDHD simulations on the original stress field in the ring weld, which also matched earlier neutron diffraction results.

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