scholarly journals Prediction of Cyclic Residual Stress Relaxation by Modeling Approach

2014 ◽  
Vol 996 ◽  
pp. 743-748 ◽  
Author(s):  
Naoufel Ben Moussa ◽  
Naziha Sidhom ◽  
Habib Sidhom ◽  
Chedly Braham
Keyword(s):  
Residual Stress ◽  
Diffraction Method ◽  
Cyclic Hardening ◽  
Cyclic Softening ◽  
Loading Path ◽  
X Ray Diffraction ◽  
X Ray ◽  
Finite Element Software ◽  
Cyclic Relaxation ◽  
Kinetics Of

A new method for prediction of residual stress cyclic relaxation has been developed and implemented in the finite element software Abaqus. The calculated profiles were validated by experimental measurements using X-ray diffraction method. This validated approach is afterward used to investigate the effect of loading path and initial residual stress characteristics on the kinetics of relaxation and the stabilized profile for both cyclic softening and cyclic hardening materials.

Experimental Investigation on Intensity and Residual Stress in Superficial Layers Induced by Water Cavitation Peening with Aeration

2008 ◽  
Vol 373-374 ◽  
pp. 754-757 ◽  
Author(s):  
Dong Ying Ju ◽  
B. Han
Keyword(s):  
Residual Stress ◽  
Process Capability ◽  
Diffraction Method ◽  
Spring Steel ◽  
Bubble Collapse ◽  
Process Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Enhancement Method ◽  
The Impact

Water cavitation peening (WCP) with aeration is a novel surface enhancement method. A new ventilation nozzle with aeration is adopted to improve the process capability of WCP by increasing the impact pressure induced by the bubble collapse on the surface of components. In this study, in order to investigate the process capability of the WCP with aeration, a standard N-type almen strips of spring steel SAE 1070 was treated by WCP with various process conditions, and the arc height value and the residual stress in the superficial layers were measured by X-ray diffraction method. The optimal fluxes of aeration and the optimal standoff distances were achieved.

Influence of Surface Roughness on the Quality of Data Obtained by Pseudo-Grazing Incidence X-Ray Diffraction

2006 ◽  
Vol 514-516 ◽  
pp. 1618-1622 ◽  
Author(s):  
Maria José Marques ◽  
J.C.P. Pina ◽  
A. Morão Dias
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Stress Gradient ◽  
Roughness Parameter ◽  
Diffraction Method ◽  
Grazing Incidence ◽  
Bragg Diffraction ◽  
X Ray Diffraction ◽  
Residual Surface Stress ◽  
X Ray

The conventional Bragg diffraction geometry, normally used to characterize the residual surface stress state, it is not suitable to evaluate surface treated materials and thin films. The X-ray path lengths through a surface layer or thin film are too short to produce adequate diffraction intensities in relation to the bulk or the substrate. Another limitation of the conventional technique appears when a residual stress gradient is present in the irradiated surface. The technique only enables the evaluation of the mean value of this gradient. In these cases, a recently proposed Pseudo-Grazing Incident X-ray Diffraction method would be better applicable. In this study, the Pseudo-Grazing Incidence X-ray Diffraction is applied to characterize the residual stress depth profiles of several AISI 4140 samples, which were prepared, by mechanical polishing and grinding, in order to present different surface roughness parameters, Ra. The experimental results lead to the conclusion that the surface roughness limits the application of the Pseudo-Grazing Incidence methodology to a minimum X-ray incident angle. This angle is the one that enables a mean X-ray penetration depth with the same order of magnitude of the sample surface roughness parameter, Ra.

Characteristics of Residual Stress in P92 Steel Welds

2007 ◽  
Vol 26-28 ◽  
pp. 1175-1180
Author(s):  
Keun Bong Yoo ◽  
Hyun Sun Choi ◽  
Eui Hyun Kim ◽  
Jae Hoon Kim
Keyword(s):  
Residual Stress ◽  
Compressive Residual Stress ◽  
Diffraction Method ◽  
Welding Residual Stress ◽  
Distribution Characteristics ◽  
X Ray Diffraction ◽  
P92 Steel ◽  
X Ray ◽  
Steel Welds ◽  
Directional Difference

Welding residual stress has important influence on the performance of engineering components. In this paper, the residual stress and FWHM were measured by X-ray diffraction method to investigate characteristics for P92 steel welds. The aim of the study is to estimate the residual stress and FWHM distribution characteristics. A compressive residual stress distributed as a function of depth has a different pattern in welds and base metal. A large tensile residual stress occurs welds and near the HAZ, but approaches gradually zero as away from the welding center. Residual stress and FWHM undergo rapid relaxation after PWHT. Also, FWHM is a scalar quantity without any directional difference and is proportional to hardness on the whole.

scholarly journals Residual Stress Tensor Distributions in Cracked Austenitic Stainless Steel Measured by Two-Dimensional X-Ray Diffraction Method

2014 ◽  
Vol 996 ◽  
pp. 128-134 ◽  
Author(s):  
Youichi Saito ◽  
Shunichiro Tanaka
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Stress Tensor ◽  
Equivalent Stress ◽  
Diffraction Method ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Stress Concentrations ◽  
X Ray

The residual stress tensor for cracked austenitic stainless steel was measured by a two-dimensional X-ray diffraction method. Higher von Mises equivalent stress concentrations, attributed to hot crack initiation, were obtained at both crack ends. The stress of 400 MPa at the crack end in the columnar grain region was about two-fold larger than that of 180 MPa in the equiaxed grain region. This difference was caused by a depression in the cast slab.

Review of Residual Stress Determination and Exploitation Techniques Using X-Ray Diffraction Method

2006 ◽  
Vol 524-525 ◽  
pp. 229-234
Author(s):  
M. Belassel ◽  
J. Pineault ◽  
M.E. Brauss
Keyword(s):  
Residual Stress ◽  
Diffraction Method ◽  
Point Of View ◽  
Stress And Strain ◽  
Stress Determination ◽  
Calculation Methods ◽  
X Ray Diffraction ◽  
X Ray ◽  
True Meaning ◽  
The Difference

Although x-ray diffraction techniques have been applied to the measurement of residual stress in the industry for decades, some of the related details are still unclear to many production and mechanical testing engineers working in the field. This is because these details, specifically those associated with the transition between diffraction and mechanics, are not always emphasized in the literature. This paper will emphasize the appropriate calculation methods and the steps necessary to perform high quality residual stress measurements. Additionally, details are given regarding the difference between mechanical and x-ray elastic constants, as well as the true meaning of stress and strain from both diffraction and strain gage point of view. Cases where the material is subject to loading above the yield limit are also included.

Residual Stress Measurements of 4H-SiC Crystals Using X-Ray Diffraction

2014 ◽  
Vol 778-780 ◽  
pp. 453-456 ◽  
Author(s):  
Masashi Nakabayashi ◽  
Tatsuo Fujimoto ◽  
Hiroshi Tsuge ◽  
Kiyoshi Kojima ◽  
Kozo Abe ◽  
...  
Keyword(s):  
Residual Stress ◽  
Temperature Distribution ◽  
Room Temperature ◽  
Radial Direction ◽  
Large Strain ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plane Direction ◽  
Lateral Temperature

The room temperature residual stress of 4H-SiC wafers has been investigated using a precise X-ray diffraction method. A large strain was observed for the circumferential direction of wafers, more than ten times larger than those measured along the principal plane direction and the radial direction. Optimizing the lateral temperature distribution in growing crystals leads to reduction of residual stress of wafers with high crystal quality.

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