Determination of Mode of Damage During Creep-Fatigue Interaction

2005 ◽  
Vol 128 (2) ◽  
pp. 248-252
Author(s):  
M. Javed Hyder
Keyword(s):  
Hysteresis Loop ◽  
Electrical Potential ◽  
Potential Method ◽  
Damage Mode ◽  
Clear Indication ◽  
Creep Fatigue ◽  
Damage Process

A technique has been developed using the reversing dc electrical potential method to determine the mode of damage taking place during creep-fatigue interaction. It is observed that the hysteresis loop created by plotting the stress verses electrical potential gives a clear indication whether the damage in process is creep dominated or fatigue-dominated. During the fatigue-dominated damage process the hysteresis loop of stress verses electrical potential changes the shape whereas during the creep-dominated damage process the hysteresis loop of stress verses electrical potential does not change the shape but moves in the direction of higher electrical potential values. These changes are observed well before any indication seen on the conventional hysteresis loop of stress verses strain. This identification of the damage mode is observed well before failure occurs. The conclusion has been confirmed through fractographs. Hence it can be said that this technique eliminates the need for fractographs when determining the mode of damage during creep-fatigue interaction.

Use of Subsized Specimen for Evaluating the Strength and Fracture Toughness of Irradiated 2 1/4 Cr-1 M0 Steel

1992 ◽  
Vol 114 (2) ◽  
pp. 168-171 ◽  
Author(s):  
X. Mao ◽  
H. Takahashi ◽  
T. Kodaira
Keyword(s):  
Fracture Toughness ◽  
Tensile Test ◽  
Ultimate Strength ◽  
Electrical Potential ◽  
Potential Method ◽  
Strength Increase ◽  
Irradiation Hardening ◽  
Small Punch ◽  
Irradiation Test

The procedure of the determination of yield and ultimate strengths of irradiated 2 1/4 Cr-1 M0 steel using small punch specimen (10 mm by 10 mm by 0.5 mm) has been demonstrated. The result was compared with the result obtained from conventional tensile test. Fracture toughness of irradiated 2 1/4 Cr-1 M0 steel was measured by use of subsized CT specimen and D. C. electrical potential method. Owing to irradiation hardening of 2 1/4 Cr-1 M0 steel, yield and ultimate strength increase substantially and fracture toughness decreases 37 percent when the steel is irradiated to a fluence of 3.2 x 1023 n/m2. The small punch and subsized CT specimen can be used for irradiation test so that considerable irradiation space will be saved.

The Determination of Electrokinetic Coupling-Coefficient and Zeta Potential of Rock Samples by Electrokinetic Measurements

2012 ◽  
Vol 516-517 ◽  
pp. 1870-1873 ◽  
Author(s):  
Jun Wang ◽  
Heng Shan Hu
Keyword(s):  
Zeta Potential ◽  
Coupling Coefficient ◽  
Streaming Potential ◽  
Potential Method ◽  
Surface Conductivity ◽  
Reliable Estimate ◽  
Surface Conductance ◽  
Streaming Current ◽  
Low Concentrations

The electrokinetic effects are important in the understanding of electric properties in porous medium. In this study, the streaming potential and streaming current of saturated samples are measured at different concentrations, then three methods are applied to obtain the zeta-potential and electrokinetic coupling coefficient. The study shows that the results obtained from streaming potential and streaming current methods agree well with each other, but the results obtained from simplified streaming potential method become seriously inaccurate at low concentrations due to the influence of surface conductance. This experimental study also provides a reliable estimate of the surface conductivity and its contribution to zeta-potential at given concentrations.

Some Unexpected Results in the Stress Calculation Around Multiple Holes in an Isotropic Plate Under In-Plane-Loads

2014 ◽  
Author(s):  
Ghazi H. Asmar ◽  
Elie A. Chakar ◽  
Toni G. Jabbour
Keyword(s):  
Finite Element ◽  
Isotropic Plate ◽  
Potential Method ◽  
The Finite Element Method ◽  
Close Proximity ◽  
Complex Fourier Series ◽  
Circular Holes ◽  
Complex Potential Method ◽  
Multiple Holes

The Schwarz alternating method, along with Muskhelishvili’s complex potential method, is used to calculate the stresses around non-intersecting circular holes in an infinite isotropic plate subjected to in-plane loads at infinity. The holes may have any size and may be disposed in any manner in the plate, and the loading may be in any direction. Complex Fourier series, whose coefficients are calculated using numerical integration, are incorporated within a Mathematica program for the determination of the tangential stress around any of the holes. The stress values obtained are then compared to published results in the literature and to results obtained using the finite element method. It is found that part of the results generated by the authors do not agree with some of the published ones, specifically, those pertaining to the locations and magnitudes of certain maximum stresses occurring around the contour of holes in a plate containing two holes at close proximity to each other. This is despite the fact that the results from the present authors’ procedure have been verified several times by finite element calculations. The object of this paper is to present and discuss the results calculated using the authors’ method and to underline the discrepancy mentioned above.

scholarly journals Determination of Thallium(I) by Hybrid Mesoporous Silica (SBA-15) Modified Electrode

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Geeta Rani ◽  
Sanjay Singh
Keyword(s):  
Mesoporous Silica ◽  
Potential Method ◽  
Selectivity Coefficient ◽  
Indicator Electrode ◽  
Carbon Paste ◽  
Chemically Modified ◽  
Best Response ◽  
Edta Solution ◽  
Paste Electrode

Chemically modified mesoporous silica material (SBA-15) was used for the construction of Tl(I) selective carbon paste electrode. The best response was found with the electrode containing 10% modifier as electrode material. The electrode has a lower detection limit of 6.0 × 10−9 M in a working concentration range of 1.0 × 10−8–1.0 × 10−1 M. The selectivity coefficient calculated by match potential method (MPM) shows the high selectivity of electrode towards Tl(I) over other tested ions. The electrode was successfully applied as an indicator electrode for the titration of 0.01 M TlNO3solution with standards EDTA solution and for sequential titration of mixture of different anions.

Determination of the Impact Location and Damage Characterization Based on Guided Waves

2016 ◽  
Vol 713 ◽  
pp. 10-13 ◽  
Author(s):  
A. de Luca ◽  
Zahra Sharif Khodaei ◽  
Francesco Caputo
Keyword(s):  
Neural Network ◽  
Guided Waves ◽  
Training Phase ◽  
Damage Mode ◽  
Impact Location ◽  
Damage Characterization ◽  
Artificial Neural Network Ann ◽  
The Impact ◽  
Damage Criteria

The aim of this paper is to understand the effects of the damage criteria modelling on the training phase (performed by means of Finite Element simulations) of an artificial neural network (ANN) enabled to locate impacts onto a CFRP laminate. The developed FE models have been also used to investigate the intra-laminar damage mode, which, among different ones, has the most effects on the residual strength of the panel.

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