Measurement of Near Surface Residual Stresses Using Electric Discharge Wire Machining

1994 ◽  
Vol 116 (1) ◽  
pp. 1-7 ◽  
Author(s):  
W. Cheng ◽  
I. Finnie ◽  
M. Gremaud ◽  
M. B. Prime
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Electric Discharge ◽  
Theoretical Approach ◽  
Stress Measurement ◽  
Stress Gradient ◽  
Experimental Results ◽  
Residual Stress Measurement ◽  
Near Surface ◽  
Surface Residual Stresses

In previous work it has been shown that near surface residual stresses may be deduced from surface strains produced by making a cut of progressively increasing depth. The process of electric discharge wire machining (EDWM), by providing very narrow cuts, greatly improves the ability of the method to resolve a stress gradient near the surface. However, the EDWM process may also introduce residual stresses. In the present work a model for estimating the influence of EDWM is presented, and a procedure for eliminating its effect on residual stress measurement is developed. Experimental results validate the theoretical approach.

Residual Stress Measurements on IN718 Fatigue Specimens Using X-Ray Diffraction Techniques

2016 ◽  
Vol 879 ◽  
pp. 578-582
Author(s):  
Yi Fei Gao ◽  
Shu Lan Wang
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Stress Measurement ◽  
Low Cycle Fatigue ◽  
Stress Gradient ◽  
X Ray Diffraction ◽  
Special Requirement ◽  
X Ray ◽  
Stress Measurements ◽  
Surface Residual Stresses

Residual stress measurements were successfully performed on the representative IN718 fatigue specimens by X-Ray Diffraction. All surface residual stresses were found to be compressive. A stress gradient normal to the surface was observed on all specimens. The residual stresses tended to become less compressive with increasing depth into the parts. Residual stress measurement is the special requirement for NADCAP CRITERIA AC 7101/7. In this paper, residual stress measurements were successfully performed on two IN718 low cycle fatigue test specimens.

Residual Stress Measurement in a Ceramic-Metallic Graded Material

2002 ◽  
Vol 124 (2) ◽  
pp. 185-191 ◽  
Author(s):  
Michael R. Hill ◽  
Wei-Yan Lin
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Error Analysis ◽  
Residual Stresses ◽  
Stress Measurement ◽  
Pure Titanium ◽  
Titanium Boride ◽  
Residual Stress Measurement ◽  
Graded Material ◽  
Strain Release

This paper presents experimental measurements of the through-thickness distribution of residual stress in a ceramic-metallic functionally graded material (FGM). It further presents an error analysis and optimization of the residual stress measurement technique. Measurements are made in a seven-layered plate with a base of commercially pure titanium and successive layers containing an increasing proportion of titanium-boride, reaching 85% titanium-boride in the final layer. The compliance method is employed to determine residual stress, where a slot is introduced using wire electric-discharge machining and strain release is measured as a function of increasing slot depth. Strain release measurements are used with a back-calculation scheme, based on finite element simulation, to provide residual stresses in the FGM. The analysis is complicated by the variation of material properties in the FGM, but tractable due to the flexibility of the finite element method. The Monte Carlo approach is used for error analysis and a method is described for optimization of the functional form assumed for the residual stresses. The magnitude and variation of the resulting residual stress distributions and several aspects of the error analyses are discussed.

Role of Quantitative NDE Techniques in Life Management of Gas Turbine Components

2006 ◽  
Author(s):  
Michael Gorelik ◽  
Waled T. Hassan ◽  
Harry Kington
Keyword(s):  
Residual Stress ◽  
Stress Gradient ◽  
Surface Residual Stress ◽  
Major Barrier ◽  
Near Surface ◽  
Life Management ◽  
Surface Residual Stresses ◽  
Engine Components ◽  
Nondestructive Measurements ◽  
Non Destructive

A number of earlier publications discussed the benefits of probabilistic analysis and probabilistic lifing in application to critical rotating engine components. One of the important variables in both probabilistic and deterministic lifing analysis is the level of residual stress in the component. Near surface residual stresses directly influence the fatigue life of critical engine rotating components. Depending on sign and magnitude a near surface residual stress gradient can either inhibit or accelerate fatigue initiation and crack propagation. A major barrier to introducing subsurface residual stress information into the life calculation process is the necessity to make accurate and reliable nondestructive measurements on as produced hardware. The paper reviews several NDE technologies that could be candidates for both production and in-service non-destructive residual stress measurements. The importance of having accurate residual stress information and its use in the probabilistic design and life management process is illustrated on several examples. A linkage with several ongoing industry R&D programs is discussed.

scholarly journals Longitudinal critically refracted (LCR) ultrasonic wave for residual stress measurement

2021 ◽  
Vol 1199 (1) ◽  
pp. 012060
Author(s):  
M Geľatko ◽  
M Hatala ◽  
R Vandžura ◽  
F Botko
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Ultrasonic Wave ◽  
Stress Measurement ◽  
Basic Structure ◽  
The State ◽  
Residual Stress Measurement ◽  
Measurement Technology ◽  
Engineering Practice ◽  
Surface Residual Stress

Abstract The article deals with the state-of-the-art in the field of Longitudinal critically refracted (LCR) ultrasonic wave, for non-destructive material evaluation. It checks its capability for residual stress identification, and reviews positives and negatives related to its use. Obtained information within the article, are used for the understanding of essence of method and for the evaluation of its use in the engineering practice. The article can be the source of information about the LCR wave measurement technology, which is the part of the complex ultrasonic testing method. For the frequency of using this technology for surface residual stress measurement, it is appropriate to have this information in one whole, which are gathered of the outputs of researches by various authors. The paper is divided in few sections and sub-sections. In the first section, information about LCR wave technique and factors correlated with this method, are provided. The next section writes about residual stresses and the importance of their identification. Next, the principal of residual stresses measurement and basic structure of measurement device, is described. A significant part of study, describes the state so far of theoretical and practical researches within the use of this method, in the technological practice of residual stress identification in surface layers of engineering components. In the conclusion, obtained knowledges are summarised and evaluated. Related positive and negative aspects are included, with a verifying the need of future researches.

scholarly journals Material Removal, Correction and Laboratory X-Ray Diffraction

2014 ◽  
Vol 996 ◽  
pp. 181-186 ◽  
Author(s):  
Eric Wasniewski ◽  
Baptiste Honnart ◽  
Fabien Lefebvre ◽  
Eric Usmial
Keyword(s):  
Residual Stress ◽  
Stress Relaxation ◽  
Stress Field ◽  
Residual Stresses ◽  
Material Removal ◽  
Stress Gradient ◽  
X Ray Diffraction ◽  
X Ray ◽  
Surface Residual Stresses ◽  
Residual Stress Gradient

Laboratory X-ray diffraction is commonly used for surface residual stresses determination. Nevertheless, the in-depth residual stress gradient also needs to be known. Chemical or electro-polishing method is generally used for material removal. However, material removal may seek a new equilibrium and stress field may change in such a way that experimental residual stress values must be corrected. Different methods exist to account for the residual stress relaxation associated with the material removal operation and will be discussed in this paper.

The NeT Task Group 6 Weld Residual Stress Measurement and Simulation Round Robin in Alloy 600/82

2016 ◽  
Author(s):  
Mike C. Smith ◽  
Ondrej Muransky ◽  
Vasileios Akrivos ◽  
Jean Angles
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Stress Measurement ◽  
Residual Stress Measurement ◽  
Collaborative Network ◽  
Alloy 600 ◽  
Aisi 316L ◽  
Numerical Techniques ◽  
Weld Residual Stress ◽  
Parallel Measurement

The mission of the NeT European collaborative network is to develop experimental and numerical techniques and standards for the reliable characterisation of residual stresses in structural welds. NeT achieves this by conducting parallel measurement and prediction round robins on closely controlled and well characterised benchmark weldments. NeT TG6 follows on from the successful TG1 and TG4 benchmarks, which both examined welds in AISI 316L material. NeT TG6 examines an Alloy 600 plate containing a three pass “slot” weld made with Alloy 82 consumables. This paper describes the NeT TG6 project as a whole, and presents preliminary materials characterisation, residual stress measurement, and residual stress modelling results.

scholarly journals Residual Stress Measurement in Coated Plates Using Layer Growing/ Removing Methods: 100Th Anniversary of the Publication of Stoney’s Paper “the Tension of Metallic Films Deposited by Electrolysis”

2011 ◽  
Vol 681 ◽  
pp. 165-170 ◽  
Author(s):  
Jakub Kõo ◽  
Jaak Valgur
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Stress Measurement ◽  
Copper Plate ◽  
Residual Stress Measurement ◽  
Metallic Films ◽  
Steel Coating ◽  
Historical Remarks

In connection with the 100th anniversary of Stoney’s equations, some historical remarks are made with respect to the development of these equations. As an example of the extension of Stoney’s equations, a unique algorithm of the layer growing/removing methods is presented for de­termination of residual stresses in isotropic inhomogeneous coated plates. Using a computer pro­gram based on this algorithm, residual stresses are computed in the galvanic steel coating on the copper plate substrate.

Residual Stress Management in Welding: Residual Stress Measurement and Improvement Treatments

2012 ◽  
Author(s):  
Jacob Kleiman ◽  
Yuri Kudryavtsev
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Residual Stresses ◽  
Stress Management ◽  
Stress Measurement ◽  
Industrial Applications ◽  
Welding Residual Stress ◽  
Residual Stress Measurement ◽  
Engineering Properties ◽  
Welded Structures

Residual stress (RS) can significantly affect engineering properties of materials and structural components, notably fatigue life, distortion, dimensional stability, corrosion resistance etc. Residual stresses play an exceptionally significant role in fatigue of welded elements. The influence of residual stresses on the multi-cycle fatigue life of butt and fillet welds can be compared with the effects of stress concentration. Even more significant are the effects of residual stresses on the fatigue life of welded elements in the case of relieving harmful tensile residual stresses and introducing beneficial compressive residual stresses in the weld toe zones. Residual stress management is a concept that addresses major aspects of residual stresses in welds and welded structures. According to the concept three major stages, i.e. RS determination, RS analysis and RS redistribution are considered and evaluated, either experimentally or theoretically to achieve the optimum performance of welded structures. All three stages as well as a number of new engineering tools such as ultrasonic computerized complex for residual stress measurement, UltraMARS, software for analysis of the effect of residual stresses on the fatigue life of welded elements and new technology and, based on it, compact system for beneficial redistribution of residual stresses by ultrasonic peening, UltraPeen will be discussed. Examples of industrial applications of the developed engineering tools for residual stress analysis and fatigue life improvement of welded elements and structures will be given.

Residual Stress Measurement Of High Molecular Matter By Transmission X-Ray Diffraction

2011 ◽  
Vol 681 ◽  
pp. 381-386 ◽  
Author(s):  
Masashi Kitamura ◽  
Nishida Masayuki ◽  
Hanabusa Takao
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Stress Measurement ◽  
Quantitative Estimation ◽  
Regression Line ◽  
Polymeric Materials ◽  
Residual Stress Measurement ◽  
Stress Distributions ◽  
Transmission Method ◽  
X Ray

In this study, the residual stresses in high-density polyethylene (HDPE) were measured using an x-ray stress measurement technique. There have been few reports published of residual stress investigations in polymeric materials by x-ray stress measurements based on conventional x-ray reflection methods. There are two problems associated with this measurement. Firstly, the diffraction peaks of the polymer in the low 2q angle region and therefore the measurement accuracy for strains reduces. Secondly, the low 2q angle region makes it extremely difficult to use the sin2ψmethod. In the present study we tried to use a transmission method for measuring the residual stress in HDPE sample to resolve these problems. The HDPE sample is shaped into thin sheets which have the three kinds of crystallinity degrees. The measured data is fitted with a good linear regression line in a d-sin2ψdiagram and gradient of the regression line corresponded to the applied stress. On the other hand, the results of the residual stress measurement are deeply associated with degrees of the crystallinity in the HDPE material. The quantitative estimation of crystallinity degrees in the HDPE material was accomplished by a sink-float method. The residual stress distributions were discussed between micro-residual stresses in the crystal phase of HDPE with the amorphous phase of it. Finally, x-ray elastic constant (XEC) of HDPE was estimated and the Initial residual stresses were also measured by use of this XEC parameter.

Investigation of the Performance of the Contour Residual Stress Measurement Method When Applied to Welded Pipe Structures

2009 ◽  
Author(s):  
R. J. Dennis ◽  
N. A. Leggatt ◽  
E. A. Kutarski
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Measurement Method ◽  
Stress Measurement ◽  
Complex Structure ◽  
Cutting Process ◽  
Residual Stress Measurement ◽  
Contour Method ◽  
Hole Drilling ◽  
Welded Pipe

The ‘Contour Method’ is a relatively new relaxation method for residual stress measurement and may be seen as an evolution of established methods such as hole drilling. The general procedure when applying the Contour Method is cutting, measurement and calculation of residual stress normal to the cut plane using Bueckner’s principle of elastic superposition. That is the residual stresses are determined from the measured profile of a cut surface. While the Contour Method is simple in concept there are certain underlying issues relating to the cutting process that may lead to uncertainties in the measured results. Principally the issues are that of constraint and plasticity during the cutting process and the influence that they have on the measured residual stresses. Both of these aspects have been investigated in previous work by simulating the entire contour measurement method process using finite element techniques for ‘simple’ flat plate welded specimens. Here that work is further investigated and extended by application to a 316 Stainless Steel welded pipe structure containing a part-circumferential repair. This more complex structure and residual stress field is of significantly greater engineering interest. The key objective of this work is to ascertain the feasibility of and further our understanding of the performance of the Contour Method. Furthermore this work has the potential to provide a method to support the optimisation of the contour measurement process when applied to more complex engineering components.

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