Stress Evaluation by Neutron and Synchrotron Radiation

2012 ◽  
Vol 188 ◽  
pp. 262-267
Author(s):  
Alain Lodini ◽  
Abdelilah Benmarouane
Keyword(s):  
Residual Stresses ◽  
Cobalt Alloys ◽  
X Ray Diffraction ◽  
Element Analysis ◽  
Stress Evaluation ◽  
X Ray ◽  
Steel Forging ◽  
Final Deformation ◽  
Imaging Instrument

In this paper we present two studies in order to evaluate the residual stresses in two materials. The first one, the residual stresses regenerated in shot peened aluminium plate by neutron diffraction on the strain imaging instrument SALSA at the Institut Laue Langevin, Grenoble, France, also the validation of a model of finite element analysis permitting to predict the final deformation. The second example of this work we use the cobalt-alloys coating deposited on stainless steel forging tools via Plasma Transfer Arc (PTA) process, the evaluation of the residual stresses and characterization of phases close to substrate/coating interface were done by Synchrotron X-ray diffraction.

Experimental/Modelling Study of Residual Stress in Al/SiCp Bent Bars by Synchrotron XRD and Slitting Eigenstrain Methods

2008 ◽  
Vol 571-572 ◽  
pp. 277-282 ◽  
Author(s):  
Xu Song ◽  
Solène Chardonnet ◽  
Giancarlo Savini ◽  
Shu Yan Zhang ◽  
Willem J.J. Vorster ◽  
...  
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Residual Strain ◽  
Numerical Models ◽  
Front Face ◽  
Stress Profile ◽  
X Ray Diffraction ◽  
Element Analysis ◽  
X Ray ◽  
Residual Stress Profile

The aim of the study presented here was to evaluate the residual stresses present in a bar of aluminium alloy 2124-T1 matrix composite (MMC) reinforced with 25vol% particulate silicon carbide (SiCp) using X-ray diffraction and 3D profilometry (curvature measurement using Mitutoyo/Renishaw coordinate measurement machine) and comparing these results with numerical models of residual strain and stress profiles obtained by a simple inelastic bending model and Finite Element Analysis (FEA). The residual strain distribution was introduced into the test piece by plastic deformation in the 4-point bending configuration. At the first stage of this study the elasticplastic behaviour of the MMC was characterized under static and cyclic loading to obtain the material parameters, hardening proprieties and cyclic hysteresis loops. Subsequently, synchrotron Xray diffraction and CMM curvature measurements were performed to deduce the residual stress profile in the central section of the bar. The experimental data obtained from these measurements were used in the inelastic bending and FEA simulations. The specimens were then subjected to incremental slitting using EDM (electric discharge machining) with continuous back and front face strain gauge monitoring. The X-ray diffraction and incremental slitting results were then analysed using direct and inverse eigenstrain methods. Residual stresses plots obtained by different methods show good agreement with each other.

Three-dimensional welding residual stresses evaluation based on the eigenstrain methodology via X-ray measurements at the surface

2014 ◽  
Vol 03 (04) ◽  
pp. 1450023
Author(s):  
Masaru Ogawa
Keyword(s):  
Neutron Diffraction ◽  
Residual Stresses ◽  
Three Dimensional ◽  
Strain Gauges ◽  
X Ray Diffraction ◽  
Stress Evaluation ◽  
X Ray ◽  
Residual Strains ◽  
Non Destructive ◽  
Evaluation Accuracy

In order to assure structural integrity for operating welded structures, it is necessary to evaluate crack growth rate and crack propagation direction for each observed crack non-destructively. Here, three dimensional (3D) welding residual stresses must be evaluated to predict crack propagation. Today, X-ray diffraction is used and the ultrasonic method has been proposed as non-destructive method to measure residual stresses. However, it is impossible to determine residual stress distributions in the thickness direction. Although residual stresses through a depth of several tens of millimeters can be evaluated non-destructively by neutron diffraction, it cannot be used as an on-site measurement technique. This is because neutron diffraction is only available in special irradiation facilities. Author pays attention to the bead flush method based on the eigenstrain methodology. In this method, 3D welding residual stresses are calculated by an elastic Finite Element Method (FEM) analysis from eigenstrains which are evaluated by an inverse analysis from released strains by strain gauges in the removal of the reinforcement of the weld. Here, the removal of the excess metal can be regarded as non-destructive treatment because toe of weld which may become crack starters can be eliminated. The effectiveness of the method has been proven for welded plates and pipes even with relatively lower bead height. In actual measurements, stress evaluation accuracy becomes poorer because measured values of strain gauges are affected by processing strains on the machined surface. In the previous studies, the author has developed the bead flush method that is free from the influence of the affecting strains by using residual strains on surface by X-ray diffraction. However, stress evaluation accuracy is not good enough because of relatively poor measurement accuracy of X-ray diffraction. In this study, a method to improve the estimation accuracy of residual stresses in this method is formulated, and it is shown numerically that inner welding residual stresses can be estimated accurately from the residual strains measured by X-ray diffraction.

Position Resolved Residual Stress Determination in Alumina-Zirconia Multilayered Ceramics

2008 ◽  
Vol 571-572 ◽  
pp. 421-425
Author(s):  
Guenther A. Maier ◽  
Jozef Keckes ◽  
Jens Brechbuehl ◽  
Hugues Guerault ◽  
Raúl Bermejo
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
X Ray Diffraction ◽  
Correct Evaluation ◽  
Indentation Method ◽  
Element Analysis ◽  
Stress Evaluation ◽  
X Ray ◽  
Residual Stress State ◽  
Experimental Findings

Alumina-zirconia multilayered ceramics have been proposed as an alternative for the design of structural ceramics with improved fracture toughness and strength reliability. During the processing of these laminates, significant residual stresses may arise due to the thermal expansion mismatch between adjacent layers. The correct evaluation of such stress distribution in the laminate may determine its range of application. In this work, the residual stress state in a layered material designed with five thick alumina layers of approximately 650 microns alternated with four thin alumina-zirconia layers of approximately 140 microns was estimated using different methods. A finite element analysis (FEM) was performed for stress evaluation in the bulk and an indentation method and X-Ray diffraction to account for stresses at the surface. Experimental findings show a constant stress distribution within the bulk for each layer, while at the surface stress position dependence is observed in the alumina layers, being the maximum tensile stresses near the layer interface. The accuracy of the results provided by each technique is discussed.

Experimental Comparison of In-Depth Residual Stresses Measured with Neutron and X-Ray Diffraction with a Numerical Stress Relaxation Correction Method

2017 ◽  
Vol 905 ◽  
pp. 131-136
Author(s):  
Bruno Levieil ◽  
Florent Bridier ◽  
Cédric Doudard ◽  
Vincent Klosek ◽  
David Thévenet ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress Relaxation ◽  
Neutron Diffraction ◽  
Residual Stresses ◽  
Correction Method ◽  
Experimental Comparison ◽  
X Ray Diffraction ◽  
Element Analysis ◽  
Notched Specimen ◽  
X Ray

This study is an experimental comparison of in-depth X-ray diffraction residual stress measurements with neutron diffraction measurements. The goal is to evaluate the relevance of the Savaria-Bridier-Bocher [1] stress relaxation correction method. Neutron diffraction are performed on a bent notched specimen. Destructive X-ray diffraction is performed until 5.25mm below the surface by polishing the material. This polishing induces stress relaxation and X-ray diffraction results have to be corrected. For that purpose, a finite element analysis is realised and show good correlation with neutron measurements results. The application of the stress correction method improves the X-ray measurements especially after 2 mm below the surface. The differences between measured and corrected residual stresses from both diffraction techniques are analyzed and discussed.

Characterization of Residual Stresses on Steel Coil Springs via X-Ray Diffraction Techniques

2016 ◽  
Vol 9 (3) ◽  
pp. 649-653
Author(s):  
Frank Anthony Cuccia ◽  
James Pineault ◽  
Mohammed Belassel ◽  
Michael Brauss
Keyword(s):  
Residual Stresses ◽  
X Ray Diffraction ◽  
X Ray ◽  
Steel Coil

scholarly journals Effect of a Multiple Reduction Die on the Residual Stress of Drawn Materials

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1358
Author(s):  
Jeong-Hun Kim ◽  
Chang-Hyun Baek ◽  
Sang-Kon Lee ◽  
Jong-Hun Kang ◽  
Joon-Hong Park ◽  
...  
Keyword(s):  
Neural Network ◽  
Residual Stress ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Residual Stresses ◽  
Deep Neural Network ◽  
Drawing Process ◽  
X Ray Diffraction ◽  
Element Analysis ◽  
X Ray

Residual stress may influence the mechanical behavior and durability of drawn materials. Thus, this study develops a multiple reduction die (MRD) that can reduce residual stress during the drawing process. The MRD set consists of several die tips, die cases, and lubricating equipment. All the die tips of the MRD were disposed of simultaneously. Finite element analysis of the drawing process was performed according to the reduction ratio of each die tip, and the variables in drawing process with the MRD were optimized using a deep neural network to minimize the residual stress. Experiments on the drawing process with the conventional die and MRD were performed to evaluate the residual stress and verify the effectiveness of the MRD. The results of X-ray diffraction measurements indicated that the axial and hoop residual stresses on the surface were dramatically reduced.

Residual Stress Characterization of A7N01-T5 Welds for High Speed Train by X-Ray Diffraction and Verification

2011 ◽  
Vol 291-294 ◽  
pp. 896-900
Author(s):  
Hua Ji ◽  
Guo Qing Gou ◽  
Hui Chen ◽  
Da Li ◽  
Chuan Ping Ma ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Residual Stresses ◽  
High Speed ◽  
High Speed Train ◽  
X Ray Diffraction ◽  
Good Qualitative Agreement ◽  
X Ray ◽  
Method Show

Welding residual stresses have an effect on many aspects of the integrity of structures but are normally one of the largest unknown stresses. Residual stresses are difficult to measure and to estimate theoretically but are often significant when compared with the service stresses. In this paper, measurement of residual stresses by X-ray diffraction technique using two different fitting methods (Gaussian and PearsonⅦ) was compared with analysis of a sample geometry by theoretical finite-element methods. The square map RS characterization of A7N01-T5 welds was shown. The results indicate RS measured by XRD and simulated by finite-element method show good qualitative agreement.

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