X-Ray Diffraction Residual Stress Measurements on Surface Treated Ti-6Al-4V for Aerospace Applications

2002 ◽  
Author(s):  
Sonia Martinez ◽  
Shamachary Sathish ◽  
M. Blodgett ◽  
Michael Shepard
Keyword(s):  
Residual Stress ◽  
X Ray Diffraction ◽  
X Ray ◽  
Stress Measurements ◽  
Aerospace Applications

Service Loading Analysis of Wind Turbine Gearbox Rolling Bearings Based on X-Ray Diffraction Residual Stress Measurements

2013 ◽  
Vol 768-769 ◽  
pp. 723-732 ◽  
Author(s):  
Jürgen Gegner ◽  
Wolfgang Nierlich
Keyword(s):  
Residual Stress ◽  
Wind Turbine ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
X Ray Diffraction ◽  
Rolling Bearings ◽  
Wind Turbine Gearbox ◽  
X Ray ◽  
Stress Measurements

Rolling bearings in wind turbine gearboxes occasionally fail prematurely by so-called white etching cracks. The appearance of the damage indicates brittle spontaneous tensile stress induced surface cracking followed by corrosion fatigue driven crack growth. An X-ray diffraction based residual stress analysis reveals vibrations in service as the root cause. The occurrence of high local friction coefficients in the rolling contact is described by a tribological model. Depth profiles of the equivalent shear and normal stresses are compared with residual stress patterns and a relevant fracture strength, respectively. White etching crack failures are reproduced on a rolling contact fatigue test rig under increased mixed friction. Causative vibration loading is evident from residual stress measurements. Cold working compressive residual stresses are an effective countermeasure.

X-ray Residual Stress Measurements Using Parallel Beam Optics

1976 ◽  
Vol 20 ◽  
pp. 393-402 ◽  
Author(s):  
Richard M. Chrenko
Keyword(s):  
Residual Stress ◽  
Grain Size ◽  
Beam Optics ◽  
X Ray Diffraction ◽  
Parallel Beam ◽  
Modes Of Operation ◽  
X Ray ◽  
Stress Measurements ◽  
Larger Sample ◽  
Special Modes

X-ray residual stress measurements have been made with a commercial portable X-ray diffraction apparatus that uses parallel beam optics and that was specifically designed for residual stress measurements. This machine differs from X-ray diffraction units using the usual parafocusing geometry in several respects, most notably reduced sample placement errors and larger sample sizes that can be accommodated. Two special modes of operation are available and will be discussed. These are the ability to use the side inclining method for stress analysis and the ability to use an oscillating ψ motion, the latter mode being useful for examining large grain size materials.

X-Ray Diffraction Study of the Effects of Uniaxial Plastic Deformation on Residual Stress Measurements

1968 ◽  
Vol 12 ◽  
pp. 269-300 ◽  
Author(s):  
A. L. Esquivel
Keyword(s):  
Residual Stress ◽  
Plastic Deformation ◽  
Diffraction Study ◽  
Stress Factors ◽  
X Ray Diffraction ◽  
Test Fixture ◽  
X Ray ◽  
Stress Measurements ◽  
Iron Aluminum ◽  
Before And After

AbstractUniaxial Plastic Deformation (UPD) has been known to produce anomalies in residual stress measurements based on x-ray diffraction techniques. This study was undertaken to determine the magnitude of the effects, if any, on residual stress calculations from various materials subjected to UPD. An x-ray diffraction study using the two-exposure method ( ψ = 0° and ψ = U5°) was made on several iron, aluminum, and titanium alloys (AISI 4340, 4330M, 4130; 2024-13, 7075-T611; Ti-6Al-4V) before and after these alloys were deformed plastically by bending on a U-bend test fixture. The x-ray peak shifts, Δ2θ0-ψ, were recorded and the x-ray stress factors, Ki, calculated by three different methods. The results indicate that UPD of the calibration specimens will increase or decrease Ki depending on the alloy. These results are discussed together with observations on the additivity of residual and applied stresses, and the per cent differences in the stress measurements based on stress factors calculated by three different methods.

S96 Residual Stress Measurements by X-ray Diffraction: Critical Evaluation of Error Sources

2008 ◽  
Vol 23 (2) ◽  
pp. 182-182
Author(s):  
R. Machado ◽  
A. Kuznetsov ◽  
C. A. Achete ◽  
T. Hirsch
Keyword(s):  
Residual Stress ◽  
Critical Evaluation ◽  
X Ray Diffraction ◽  
Error Sources ◽  
X Ray ◽  
Stress Measurements

Through Thickness Residual Stress Measurements by Neutron Diffraction and Hole Drilling in a Single Laser-Peened Spot on a Thin Aluminium Plate

2013 ◽  
Vol 772 ◽  
pp. 167-172 ◽  
Author(s):  
M. Burak Toparli ◽  
Michael E. Fitzpatrick
Keyword(s):  
Residual Stress ◽  
Neutron Diffraction ◽  
Diffraction Peak ◽  
Thin Plates ◽  
Hole Drilling ◽  
Stress Profile ◽  
X Ray Diffraction ◽  
X Ray ◽  
Stress Measurements ◽  
Incremental Hole Drilling

Residual stress measurements are very challenging in thin aluminium plates. Rolling-induced crystallographic texture can lead to an S-shape fit when using the sin2ψ method for surface X-ray diffraction. Peak broadening and missing peaks can also be observed for synchrotron X-ray diffraction with conventional θ/2θ scanning due to texture. In addition, when measuring near the plate surfaces, partially-filled gauge volumes in diffraction experiments will lead to “pseudo-strains”, an apparent shift between measured and actual positions for the diffraction peak. Obtaining a meaningful value of d0 for strain calculations is another issue for diffraction experiments in thin plates. The low thickness also offers challenges for destructive methods including incremental hole drilling, i.e. there is no defined ASTM standard for measuring non-uniform residual stress profile for thin plates. In this work, 2-mm-thick Al2024-T351 plate was investigated for residual stress fields due to laser peening. Neutron diffraction measurements were carried out at POLDI (Pulse Overlap time-of-flight Diffractometer) in PSI, Switzerland and the results are compared with incremental hole drilling.

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