Influence of residual stress on elastic modulus and hardness of soda-lime glass measured by nanoindentation

2004 ◽  
Vol 19 (10) ◽  
pp. 3109-3119 ◽  
Author(s):  
K.O. Kese ◽  
Z.C. Li ◽  
B. Bergman
Keyword(s):  
Residual Stress ◽  
Elastic Modulus ◽  
Stress Field ◽  
Soda Lime ◽  
Soda Lime Glass ◽  
Residual Stress Field ◽  
Contact Areas ◽  
Atomic Force ◽  
Applied Stresses

The influence of stress on the elastic modulus E and hardness H in soda-lime glass was studied in the Vickers residual stress field by nanoindentation. The Oliver–Pharr method of analysis first gave higher values of E and H, but after correcting for the pileup contact areas around the nanoindents, results consistent with literature values were obtained at regions in the stress field where the stresses were either low or close to zero. Determination of the pileup contact areas was made possible by the use of the atomic force microscope, which has facility for generating cross-section images of the indents. The elastic modulus was found to decrease with stress, which is explained with reference to the influence of applied stresses on the Si–O–Si bond angle. The hardness on the other hand did not depend on the stresses except in the region very close to the edge of the Vickers indent where the stresses are high.

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 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.

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.

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.

Full Thermal Simulation of an Arbitrary, Plane Axisymmetric Residual Stress Field

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Anthony P. Parker
Keyword(s):  
Residual Stress ◽  
Stress Field ◽  
Pressure Vessels ◽  
Thermal Simulation ◽  
Residual Stress Field ◽  
Subsequent Determination ◽  
Arbitrary Plane ◽  
Stress Profiles ◽  
Hoop Stresses

Abstract In this paper, numerical formulations are presented; these permit full thermal simulation of an arbitrary plane axisymmetric residual stress field encompassing hoop, radial, and axial stresses. Earlier formulations were based upon the determination of a temperature profile within the tube that could only replicate radial and hoop stresses; in general, axial stresses were incorrect. This new thermal simulation provides all three stresses and is achieved by incorporating orthotropic coefficients of thermal expansion that themselves vary with radius. Results are generally highly accurate. Crucial near-bore hoop and axial stresses can be replicated within 1%. Near-bore behavior is discussed in detail. These formulations will permit subsequent determination of stress intensity factors (SIF) for arbitrarily orientated cracks within pressure vessels in the presence of pre-existing residual stresses. Note that these thermal solutions mimic known, residual stress profiles; they do not predict residual stress profiles.

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