Development of the Neutron Diffraction Technique for the Determination of Near Surface Residual Stresses in Critical Gas Turbine Components

1992 ◽  
pp. 535-543 ◽  
Author(s):  
A. N. Ezeilo ◽  
P. S. Webster ◽  
G. A. Webster ◽  
P. J. Webster
Keyword(s):  
Neutron Diffraction ◽  
Residual Stresses ◽  
Gas Turbine ◽  
Near Surface ◽  
Surface Residual Stresses ◽  
Neutron Diffraction Technique

Residual Stress Measurements by Means of Neutron Diffraction

1989 ◽  
Vol 166 ◽  
Author(s):  
H. J. Prask ◽  
C. S. Choi
Keyword(s):  
Residual Stress ◽  
Neutron Diffraction ◽  
Residual Stresses ◽  
Test Specimen ◽  
Hardened Steel ◽  
Fatigue Lifetime ◽  
Near Surface ◽  
Surface Residual Stresses ◽  
Lifetime Test

ABSTRACTEnergy-dispersive neutron diffraction has been developed at the NIST reactor as a probe of sub- and near-surface residual stresses in technological samples. Application of the technique has been made to a variety of metallurgical specimens which includes the determination of tri-axial stresses as a function of depth in a number of uranium-3/4wt%Ti samples with different thermo-mechanical histories, and in two types of 7075-T6 aluminum “ogives”- of interest to the Army. Preliminary results have been obtained for an induction-hardened steel shaft, a fatigue lifetime test specimen for the SAE.

scholarly journals Neutron Diffraction Evaluation of Near Surface Residual Stresses at Welds in 1300 MPa Yield Strength Steel

Materials ◽  
2017 ◽  
Vol 10 (6) ◽  
pp. 593 ◽  
Author(s):  
Ebrahim Harati ◽  
Leif Karlsson ◽  
Lars-Erik Svensson ◽  
Thilo Pirling ◽  
Kamellia Dalaei
Keyword(s):  
Neutron Diffraction ◽  
Yield Strength ◽  
Residual Stresses ◽  
Near Surface ◽  
Surface Residual Stresses

Determination of near surface residual stresses on welded joints using ultrasonic methods

1995 ◽  
Vol 28 (2) ◽  
pp. 83-88 ◽  
Author(s):  
E. Tanala ◽  
G. Bourse ◽  
M. Fremiot ◽  
J.F. De Belleval
Keyword(s):  
Residual Stresses ◽  
Welded Joints ◽  
Near Surface ◽  
Ultrasonic Methods ◽  
Surface Residual Stresses

The Compliance Method for Measurement of Near Surface Residual Stresses—Analytical Background

1994 ◽  
Vol 116 (4) ◽  
pp. 550-555 ◽  
Author(s):  
M. Gremaud ◽  
W. Cheng ◽  
I. Finnie ◽  
M. B. Prime
Keyword(s):  
Numerical Simulation ◽  
Residual Stresses ◽  
Random Errors ◽  
Residual Stress Field ◽  
Near Surface ◽  
Surface Residual Stresses ◽  
Zero Shift ◽  
Stress States ◽  
The Stability ◽  
Piecewise Functions

Introducing a thin cut from the surface of a part containing residual stresses produces a change in strain on the surface. When the strains are measured as a function of the depth of the cut, residual stresses near the surface can be estimated using the compliance method. In previous work, the unknown residual stress field was represented by a series of continuous polynomials. The present paper shows that for stress states with steep gradients, superior predictions are obtained by using “overlapping piecewise functions” to represent the stresses. The stability of the method under the influence of random errors and a zero shift is demonstrated by numerical simulation.

Neutron diffraction measurements for the determination of residual stresses in MMC tensile and fatigue specimens

2000 ◽  
Vol 276-278 ◽  
pp. 923-924 ◽  
Author(s):  
F Fiori ◽  
E Girardin ◽  
A Giuliani ◽  
T Lorentzen ◽  
A Pyzalla ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Residual Stresses

scholarly journals Advances in Neutron Diffraction for Engineering Residual Stress Measurements

1999 ◽  
Vol 33 (1-4) ◽  
pp. 151-171 ◽  
Author(s):  
A. N. Ezeilo ◽  
G. A. Webster
Keyword(s):  
Residual Stress ◽  
Neutron Diffraction ◽  
Residual Stresses ◽  
Measuring Method ◽  
Manufacturing Processes ◽  
Stress Measurements ◽  
Code Of Practice ◽  
Numerical Predictions ◽  
Engineering Materials ◽  
Neutron Diffraction Technique

The increasing awareness amongst engineers and designers, of the significance of residual stresses in influencing the useful lifetimes of engineering components, has resulted in more demanding expectations being placed on the methods used to obtain these stresses. The neutron diffraction technique is emerging as the most attractive measuring method as the residual stresses can usually be obtained non-destructively to depths of up to 40 mm in some common engineering materials. Although it is a relatively new technique it has been used to measure the residual stresses in a range of engineering materials introduced by a wide variety of manufacturing processes such as welding, quenching, machining, shot peening, cold hole expansion and autofrettage.In this paper the neutron diffraction technique for non-destructive residual stress measurements will be described including methods used to validate the measurements. Precautions that should be taken in order to obtain reliable measurements are outlined. Procedures being investigated in order to produce a code of practice will be presented. A representative selection of stress distributions developed by a range of manufacturing processes is examined. Some comparisons are made with strain gauge, X-ray and numerical predictions. It is shown how the results can be of benefit in engineering stress analysis.

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