Advances in Hole-Drilling Residual Stress Measurements

Schajer, G. S.

doi:10.1007/s11340-009-9228-7

Cited by 126 publications

(69 citation statements)

References 60 publications

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“…A small hole is drilled on the specimen with a cylindrical end-mill, and the deformation on the surface is measured using a strain gauge rosette [8][9][10][11][12]. With this value, it is possible to calculate the stresses released in the specimen that are commonly biaxial [13,14].…”

Section: Introductionmentioning

confidence: 99%

Residual stresses in 18CrNiMo7-6 linear friction welded high strength steel chains

Nunes

Effertz

Quintino

et al. 2018

Int J Adv Manuf Technol

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Linear friction welding is a solid-state process that comprises rapid heating and cooling of the welded parts. Residual stresses (RS) as in every other welding process cannot be avoided. The presence of RS compromises the in-service performance and reliability. They influence stress corrosion cracking, fatigue strength, and the crack growth rate. Knowing the magnitude and nature of such stresses is critical for improving the quality of welded joints. Therefore, four different manufacturing stages of linear friction welded chain links were analyzed in the present study: "as forged" (F), "as welded" (A), "as welded" without flash (N), and post weld heat treated (P). The residual stress field was measured using the hole drilling (HD) method. The results of the hole drilling method showed to be independent of the measured position and symmetry with respect to the weld was observed in all evaluated regions. Close to the weld center line (WCL), the compressive stresses present in the "as forged" condition switched to tensile as a result of the welding process. However, in further regions, stresses remained almost unchanged for either A and N. The PWHT uniformizes the residual stress field along the whole weld region.

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Section: Introductionmentioning

confidence: 99%

Residual stresses in 18CrNiMo7-6 linear friction welded high strength steel chains

Nunes

Effertz

Quintino

et al. 2018

Int J Adv Manuf Technol

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“…Other difficulties stem from the noticeable perturbation exerted by the notch on the RS field, resulting in considerable lateral gradients (on the order of tens of MPa/μm), as well as from the fact that notches are frequently located at the intersection of peened surfaces, hence the RS field is affected by the interaction between the plastic strain fields produced on the outer layers of the treated surfaces. In view of these considerations, blindhole-drilling [34], conventional X-ray [35] and neutron diffraction [36] appear to be not suitable, since they probe regions of millimetre dimensions, which are too large to resolve steep lateral RS gradients. Residual strain measurements with high lateral spatial resolution have been already done in the past using synchrotron XRD, mainly to determine crack-tip strain fields [37][38][39][40].…”

Section: Introductionmentioning

confidence: 99%

High Spatial Resolution Evaluation of Residual Stresses in Shot Peened Specimens Containing Sharp and Blunt Notches by Micro-hole Drilling, Micro-slot Cutting and Micro-X-ray Diffraction Methods

et al. 2016

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The moderately high lateral RS gradients (on the order of tens of MPa/μm) near shot peened notches in conjunction with the shallow treatment depth (some hundreds of microns) limit the application of far-field and/or high resolution synchrotron diffraction residual stress measurement techniques. Recently proposed Focused Ion Beam -Scanning Elecron Microscope -Digital Image Correlation (FIB-SEM-DIC) based micro mechanical stress relaxation methods for the measurement of residual stress at the micron scale became suitable techniques for local evaluation of residual stresses and stress gradients in shot peened specimens. In this paper ultra-high resolution (~0.5-0.8 μm depth and 5-10 μm lateral resolution) mechanical relaxation stress measurements were used to evaluate the stress variation local to individual peening dimples in ceramic (60-120 μm diameter beads) shot peened Al-7075-T651 double notched samples having 0.15, 0.5 and 2.0 mm radii using Micro-Hole Drilling (μHD), Micro-Slot Cutting (μSC) and micro X-ray Diffraction (μXRD) methods. The micron-sized sampling volumes enabled the stress to be evaluated in individual impact craters (dimples) showing significant point-to-point variation (~+/−150 MPa) (with certain dimples even recording tensile stresses). After around 30 μm of layer removal the heavily deformed region had largely been removed and the stress profile became much more homogeneous. At this depth the μHD and μSC results were in good accord with those from μXRD measurements which sample over a much larger volume (~40 μm depth × 50 μm laterally) showing an in-plane compressive stress of around 150 MPa far from the notches with the residual stress rising to about 200 MPa at a blunt (2 mm) notch and 500 MPa for a sharp (0.15 mm) one. Further, these recorded variations of residual stresses were correlated with microstructural features, e.g. grains, networks of sub-surface cracks, intermetallics and highly deformed sub-surface regions, revealed by large volume Serial Sectioning Tomography using Plasma Xe + Focus Ion Beam -Scanning Electron Microscope (PFIB-SEM), EDS and EBSD maps. This allowed for the first time characterize large volume (100 × 66 × 30 μm 3 ) of shot peened regions with resolution of dozens of nanometers and correlate residual stress depth profiles with 3D microstructural features. Finally, in (Benedetti et al. 2016, Int. J. Fatigue) these RS measurements are used to reconstruct the RS field through finite element (FE) analyses.

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“…Even though the X-ray diffraction method has its own inaccuracies, it was determined accurate enough in a roughly-isotropic shot-peened sample. [6] …”

Section: Introductionmentioning

confidence: 99%

Effects of Numerical Methods on Residual Stress Evaluation by the Incremental Hole-Drilling Technique Using the Integral Method

Gore

Nobre

2016

Residual Stresses 2016

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Abstract. The incremental hole-drilling technique with Integral Method is widely used to estimate residual stresses. However, the fundamental nature of the Inverse Problem leads to numerically unstable results, which makes stress calculations very sensitive to measurement errors. The extent of this sensitivity is investigated by comparing different combinations of numerical methods for interpolating the input data and solving the equations. The methods are tested on both an experimental and simulated hole-drilling procedure to isolate inaccuracies due to numerical illconditioning and experimental errors. In the experiment, residual stresses determined by X-ray diffraction on a shot-peened sample were taken as the reference for comparison purposes. It was found that interpolating experimental data provides more stable results. Tikhonov Regularisation was more stable than direct methods, but susceptible to numerical errors introduced by the interpolation of input data.

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Advances in Hole-Drilling Residual Stress Measurements

Cited by 126 publications

References 60 publications

Residual stresses in 18CrNiMo7-6 linear friction welded high strength steel chains

Residual stresses in 18CrNiMo7-6 linear friction welded high strength steel chains

High Spatial Resolution Evaluation of Residual Stresses in Shot Peened Specimens Containing Sharp and Blunt Notches by Micro-hole Drilling, Micro-slot Cutting and Micro-X-ray Diffraction Methods

Effects of Numerical Methods on Residual Stress Evaluation by the Incremental Hole-Drilling Technique Using the Integral Method

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