An Improved Split-Ring Method for Measuring the Level of Autofrettage in Thick-Walled Cylinders

1998 ◽  
Vol 120 (1) ◽  
pp. 69-73 ◽  
Author(s):  
M. Perl
Keyword(s):  
Residual Stress ◽  
Test Specimen ◽  
Opening Angle ◽  
Residual Stress Field ◽  
Hoop Strain ◽  
Approximate Relation ◽  
Split Ring ◽  
Strain Measurements ◽  
Ring Method

A simple, yet improved, experimental method for measuring the level of autofrettage in thick-walled cylinders, such as gun barrels, is proposed. A representative ring cut from the barrel serves as the test specimen. The ring is split by cutting it radially, while measuring the released hoop strain at the inner and outer surfaces diametrically opposite from the split line. The opening angle resulting from the spring apart from the ring is also monitored. An analysis based on Hill’s residual stress field yields an approximate relation which readily enables the determination of the prevailing level of autofrettage from strain measurements as well as from the value of the opening angle. This relation is found to be practically universal for all relevant cylinder configurations b/a = 1.6–2.2 and all levels of autofrettage of up to φ = 100 percent.

A Method for Measurement of Axisymmetric Axial Residual Stresses in Circumferentially Welded Thin-Walled Cylinders

1985 ◽  
Vol 107 (3) ◽  
pp. 181-185 ◽  
Author(s):  
Weili Cheng ◽  
Iain Finnie
Keyword(s):  
Residual Stress ◽  
Stress Field ◽  
Axial Component ◽  
Residual Stress Field ◽  
Strain Measurements ◽  
Thin Walled ◽  
Predicted Values ◽  
Inside Wall ◽  
Good Agreement

A new method is proposed for measuring the axial component of an axisymmetric residual stress field in thin-walled cylinders. The specific application considered is determination of the stress at the centerline of a circumferential weld. The method involves strain measurements at the outside wall while a complete circumferential slit is cut to increasing depths from the inside wall. The technique is applied to the simple case of a single pass weld. Experimental results are in good agreement with predicted values.

Temperature and Residual Stress Fields in an Austenitic Circumferential Pipe Weld

2002 ◽  
Author(s):  
Ruthard Bonn ◽  
Klaus Metzner ◽  
H. Kockelmann ◽  
E. Roos ◽  
L. Stumpfrock
Keyword(s):  
Residual Stress ◽  
Numerical Calculation ◽  
Stress Field ◽  
Quantitative Determination ◽  
Welding Residual Stress ◽  
Stress Fields ◽  
Residual Stress Field ◽  
Circumferential Welds ◽  
The Impact

The main target of a research programme “experimental and numerical analyses on the residual stress field in the area of circumferential welds in austenitic pipe welds”, sponsored by Technische Vereinigung der Großkraftwerksbetreiber e. V. (VGB) and carried out at MPA Stuttgart, was the validation of the numerical calculation for the quantitative determination of residual stress fields in austenitic circumferential pipe welds. In addition, the influence of operational stresses as well as the impact of the pressure test on the residual stress state had to be examined. By using the TIG orbital welding technique, circumferential welds (Material X 10 CrNiNb 18 9 (1.4550, corresponding to TP 347) were produced (geometric dimensions 255.4 mm I.D. × 8.8 mm wall) with welding boundary conditions and weld parameters (number of weld layers and weld built-up, seam volume, heat input) which are representative for pipings in power plants. Deformation and temperature measurements accompanying the welding, as well as the experimentally determined (X-ray diffraction) welding residual stress distribution, served as the basis for the verification of numeric temperature and residual stress field calculations. The material model on which the calculations were founded was developed by experimental weld simulations in the thermo-mechanical test rig GLEEBLE 2000 for the determination of the material behaviour at different temperatures and elasto-plastic deformation. The numeric calculations were carried out with the Finite Element program ABAQUS. The comparison of the calculation results with the experimental findings confirms the proven validation of the developed numerical calculation models for the quantitative determination of residual stresses in austenitic circumferential pipings. The investigation gives a well-founded insight into the complex thermo-mechanical processes during welding, not known to this extent from literature previously.

Determination of Residual Stress in Beams Under Bauschinger Effect Using Surface Strain Measurements

Strain ◽  
2003 ◽  
Vol 39 (4) ◽  
pp. 177-185 ◽  
Author(s):  
G. Urriolagoitia-Sosa ◽  
J. F. Durodola ◽  
N. A. Fellows
Keyword(s):  
Residual Stress ◽  
Bauschinger Effect ◽  
Surface Strain ◽  
Strain Measurements

Determination of the Residual Stress Field around Scratches Using Synchrotron X-Rays and Nanoindentation

2010 ◽  
Vol 652 ◽  
pp. 25-30
Author(s):  
M.K. Khan ◽  
Michael E. Fitzpatrick ◽  
L.E. Edwards ◽  
S.V. Hainsworth
Keyword(s):  
Residual Stress ◽  
Stress Field ◽  
Residual Stresses ◽  
Small Scale ◽  
X Rays ◽  
X Ray Diffraction ◽  
Residual Stress Field ◽  
Fine Grained ◽  
Load Displacement

The residual strain field around the scratches of 125µm depth and 5µm root radius have been measured from the Synchrotron X-ray diffraction. Scratches were produced using different tools in fine-grained aluminium alloy AA 5091. Residual stresses up to +1700 micro-strains were measured at the scratch tip for one tool but remained up to only +1000 micro-strains for the other tool scratch. The load-displacement curves obtained from nanoindentation were used to determine the residual stresses around the scratches. It was found that the load-displacement curves are sensitive to any local residual stress field present and behave according to the type of residual stresses. This combination of nanoindentation and synchrotron X-rays has been proved highly effective for the study of small-scale residual stresses around the features such as scratches.

Assessment of the Crack Compliance Method and the Introduction of Residual Stresses by Shot Peening Using the Finite Element Method

2009 ◽  
Vol 15 ◽  
pp. 109-114 ◽  
Author(s):  
G. Urriolagoitia-Sosa ◽  
E. Zaldivar-González ◽  
J.M. Sandoval Pineda ◽  
J. García-Lira
Keyword(s):  
Numerical Simulation ◽  
Residual Stress ◽  
Stress Field ◽  
Residual Stresses ◽  
Shot Peening ◽  
Working Life ◽  
The Finite Element Method ◽  
Residual Stress Field ◽  
Main Effect

The interest on the application of the shot peening process to arrest and/or delay crack growth is rising. The main effect of the shot peening technique is to introduce a residual stress field that increases the working life of mechanical components. In this paper, it is presented the numerical simulation (FEM) of the shot peening process and the effect of introducing a residual stress field. Besides, the consequence of changing the sizes of the impacting ball is analyzed. This work also used the Crack Compliance Method (CCM) for the determination of residual stresses in beams subjected to a numerical simulation of a shot peening process. The numerical results obtained provide a quantitative demonstration of the effect of shot peening on the introduction of residual stresses by using different sizes of impacting balls and assess the efficiency of the CCM.

A New Method for Predicting the Opening Angle for Soft Tissues

2002 ◽  
Vol 124 (4) ◽  
pp. 347-354 ◽  
Author(s):  
Timothy J. Van Dyke ◽  
Anne Hoger
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stress Field ◽  
Potential Energy ◽  
Biological Tissue ◽  
Soft Tissues ◽  
Element Model ◽  
New Method ◽  
Opening Angle ◽  
Residual Stress Field

The purpose of this paper is to present a simple new method for calculating the opening angle produced by a given residual stress field in a soft biological tissue. The method uses minimization of potential energy, and is therefore named the MPE method. The accuracy of the MPE method is evaluated by comparing the opening angle it predicts to results from a finite element model of the opening angle experiment. We show that the MPE method provides good predictions of the opening angle, and that it is significantly more accurate than two other methods previously used in the literature.

scholarly journals Influence of stress ratio on residual stress evolution near cold-expanded hole due to low-cycle fatigue by crack compliance data

2020 ◽  
Vol 15 (55) ◽  
pp. 174-186
Author(s):  
Andrey Chernov ◽  
Sviatoslav Eleonsky ◽  
Vladimir Pisarev
Keyword(s):  
Residual Stress ◽  
Stress Ratio ◽  
Low Cycle Fatigue ◽  
Quantitative Description ◽  
Stress Range ◽  
Cycle Fatigue ◽  
Stress Evolution ◽  
Residual Stress Field ◽  
Field Influence

Modified version of the crack compliance method is used for determination of stress intensity factor (SIF) related to narrow notches emanating from cold-expanded holes. These notches are inserted at different stages of low-cycle fatigue under constant external load. It is shown how residual SIF values, generated by residual stress field influence, can be separated from total experimental SIF values. Residual SIF values, obtained at different stage of low-cycle fatigue with the same stress range Δσ  = 350 MPa but different stress  R = –0.4 and  R = –1.0, provide quantitative description of residual stress evolution near cold-expanded hole. It shown that maximal residual stress relaxation of order 20 per cent occurs at 95 lifetime per cent for both loading programs.

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