Bayesian Inference Method for Failure Probability of Wall Thinning Pipe in Corrosion Rate Fluctuation Model

2008 ◽  
Author(s):  
Satoshi Okajima ◽  
Satoshi Izumi ◽  
Shinsuke Sakai
Keyword(s):  
Corrosion Rate ◽  
Failure Probability ◽  
Error Term ◽  
Correction Term ◽  
Operational Environment ◽  
Bayes Method ◽  
Wall Thinning ◽  
Rate Fluctuation ◽  
The One ◽  
Linear Bayes

To rationalize the inspection interval for the wall-thinning piping element, the linear-Bayes method was proposed in the previous paper. To derive the simple formula, the linear-Bayes method ignores the corrosion rate change against time. However, this change may be caused by the one of the operational environment. Therefore, without the sufficient monitoring of the environment, the linear-Bayes method may underestimate the failure probability. In this paper, the linear-Bayes method is extended for the wall-thinning model with the corrosion rate fluctuation, which imitates the unexpected change of the corrosion rate. The extension is carried out through following two approaches: the “correction-term” and the “error-term” approaches. The correction-term approach can evaluate the change of corrosion rate, however, it requires sufficient number of inspections. The error-term approach evaluates the failure probability conservatively.

Sensitization of the SST Turbulence Model to Rotation and Curvature by Applying the Spalart–Shur Correction Term

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Pavel E. Smirnov ◽  
Florian R. Menter
Keyword(s):  
Turbulent Flows ◽  
Turbulence Model ◽  
Transport Model ◽  
Correction Term ◽  
Computational Cost ◽  
Turbulence Models ◽  
Reynolds Stress Transport Model ◽  
Wide Range ◽  
Sst Model ◽  
The One

A rotation-curvature correction suggested earlier by Spalart and Shur (1997, “On the Sensitization of Turbulence Models to Rotation and Curvature,” Aerosp. Sci. Technol., 1(5), pp. 297–302) for the one-equation Spalart–Allmaras turbulence model is adapted to the shear stress transport model. This new version of the model (SST-CC) has been extensively tested on a wide range of both wall-bounded and free shear turbulent flows with system rotation and/or streamline curvature. Predictions of the SST-CC model are compared with available experimental and direct numerical simulations (DNS) data, on the one hand, and with the corresponding results of the original SST model and advanced Reynolds stress transport model (RSM), on the other hand. It is found that in terms of accuracy the proposed model significantly improves the original SST model and is quite competitive with the RSM, whereas its computational cost is significantly less than that of the RSM.

scholarly journals The Effects Of Asymmetric Transmission Of Exchange Rate On Inflation In Iran: Application Of Threshold Models

2015 ◽  
Vol 10 (2) ◽  
pp. 99-113
Author(s):  
Yazdan Naghdi ◽  
Soheila Kaghazian
Keyword(s):  
Exchange Rate ◽  
Time Series Data ◽  
Public Procurement ◽  
Consumer Price Index ◽  
Series Data ◽  
Asymmetric Transmission ◽  
Exchange Rate Fluctuation ◽  
Rate Fluctuation ◽  
Non Linear ◽  
The One

Abstract Given the recent fluctuation in the exchange rate and the presence of several factors such as the various economy-political sanctions (mainly embargos on oil and banking), extreme volatility in different economic fields, and consequently the devaluation of national and public procurement -A landmark that is emanating from exchange rate fluctuation - two points should be noted: First, it is essential to review the effect of exchange rate fluctuation on macro economic variables such as inflation and to provide appropriate policies. Second, the existence of this condition provides the chance to study the relation between exchange rate and inflation in a non-linear and asymmetric method. Hence, the present study seeks to use TAR model and, on the basis of monthly time series data over the period March 2002 to March 2014, to analyze the cross-asymmetric and non-linear exchange rate on consumer price index (CPI) in Iran. The results also show the presence of an asymmetric long-term relationship between these variables (exchange rate and CPI). Also, in the Iranian economy, the effect of negative shocks of exchange rate on inflation is more sustainable than the one from positive shocks.

Failure Probability Assessment of Piping Systems Affected by SCC and Pipe Wall Thinning for LBB Analysis

2011 ◽  
Author(s):  
Hiromasa Chitose ◽  
Hideo Machida ◽  
Itaru Saito
Keyword(s):  
Failure Probability ◽  
Nuclear Power ◽  
Power Plants ◽  
Pipe Wall ◽  
Probability Assessment ◽  
Wall Thinning ◽  
Piping Systems ◽  
Leak Before Break ◽  
Thinning Rate ◽  
Service Inspection

This paper provides failure probability assessment results for piping systems affected by stress corrosion cracking (SCC) and pipe wall thinning in nuclear power plants. On the basis of the results, considerations for applying the leak-before-break (LBB) concept in actual plants are presented. The failure probability for SCC satisfies the target failure probability even if conservative conditions are assumed. Moreover, for pipe wall thinning analysis, pre-service inspection is important for satisfying the target failure probability because the initial wall thickness affects the accuracy of the wall thinning rate. The pipe wall thinning analysis revealed that the failure probability is higher than the target probability if the bending stress in the pipe is large.

scholarly journals A re-examination of the adiabatic correction term for the hydrogen molecule

1976 ◽  
Vol 54 (4) ◽  
pp. 651-656 ◽  
Author(s):  
Huw O. Pritchard ◽  
Lutosław Wolniewicz
Keyword(s):  
Energy Level ◽  
Hydrogen Molecule ◽  
Vibrational Energy ◽  
Correction Term ◽  
Internuclear Separation ◽  
Vibrational Energy Level ◽  
The Difference ◽  
The One

The adiabatic coupling correction term [Formula: see text] has been evaluated by two methods, the one used by Kołos and Wolniewicz in 1964 and the one suggested by Kari, Chan, Hunter, and Pritchard in 1973. The difference between the two procedures for H2 amounts to 0.04 cm−1 and is almost independent of internuclear separation in the range R = 1.0–1.8 a.u. Thus, the method of computing the ΔR-term does not affect the vibrational energy level spacings.

Berry pericarp ontogenesis from fertilization to maturity of Vitis vinifera L. var Merlot

OENO One ◽  
1997 ◽  
Vol 31 (3) ◽  
pp. 109 ◽  
Author(s):  
Monique Fougère-Rifot ◽  
H.-S. Park ◽  
Jacques Bouard
Keyword(s):  
Cell Number ◽  
Grape Berry ◽  
Ovary Wall ◽  
Vascular Bundles ◽  
Berry Skin ◽  
Wall Thinning ◽  
Fruit Setting ◽  
Parenchyma Cells ◽  
Pulp Cells ◽  
The One

<p style="text-align: justify;">Grape-flower ovary transformations is followed from fertilized flower to berry came to maturity. Cell transformations are studied, especially vacuolar tannins, starch and cell wall thinning :</p><p style="text-align: justify;">- From fruit setting to veraison, cell number of carpellary wall located between outer epidennis and vascular bundles is multiplied by 2.</p><p style="text-align: justify;">- Cell size increase considerably but by different means according to tissues: hypodennis cells elongate tangentially while inner parenchyma cells round.</p><p style="text-align: justify;">- Vacuolar tannins content in internal parenchyma cells decrease as soon as ovary is fertilized. During growth and veraison tannic cell number decrease. At maturity, only the most external cells (superficial hypodennis) still have vacuolar tannins. All the other cells of ovary wall have no more tannins.</p><p style="text-align: justify;">- Wall thickness decrease begins as soon as growth starts and this phenomena is continuous to maturity. The wall thinning down begins near the locules of ovary and is propagated towards the ouside of pericarp.</p><p style="text-align: justify;">- Amyloplasts disappear progressively. At maturity, there is scarcely no more startch in grape-berry.</p><p style="text-align: justify;">In short, except cells of berry skin, all the cells of ovary wall enlarge, lost their vacuolar tannins and the cell walls become very thin ; they are pulp cells.</p><p style="text-align: justify;">ln the pericarp of mature berry, hypodennis is very thin (less than 50 μm in places and 2-5 layers of cells). Pulp or flesh takes up a great place.</p><p style="text-align: justify;">This work is consecutived to the one on ovary before fertilization (FOUGÈRE-RIFOT et al., 1995) that shown 20 development stages from ovary primordia to the fertilized egg. From fertilized ovary to mature berry the development of pericarp is divided into 5 stages (stages 21 to 25) :</p><p style="text-align: justify;">- Stage 21 : first appearance of ovary inflation. Ovary takes a round shape. The thickness of carpellary wall is about 300 μm.</p><p style="text-align: justify;">- Stage 22 : fruit setting. Vacuolar tannins of inner parenchym disappear.</p><p style="text-align: justify;">- Stage 23 : berry growth.</p><p style="text-align: justify;">- Stage 23A : transformation of inner parenchym into pulp.</p><p style="text-align: justify;">- Stage 238 : transformation of deep hypodennis into pulp</p><p style="text-align: justify;">- Stage 23C : pulp cell enlargement.</p><p style="text-align: justify;">- Stage 24 : veraison. The definitive size of the berry is about reached.</p><p style="text-align: justify;">- Stage 24A : beginning of veraison. The hypodermis has still some thick walls.</p><p style="text-align: justify;">- Stage 248 : end of veraison. The hypodennis cells near the outer pulp cells change into pulp cells</p><p style="text-align: justify;">- Stage 25: maturity. Pulp is became very developped.</p>

A Master S-N Curve Representation of Subsea Umbilical Tube Weld Fatigue Data

2010 ◽  
Author(s):  
Pingsha Dong ◽  
Xinhua Yang
Keyword(s):  
Stress Ratio ◽  
Correction Term ◽  
Fatigue Loading ◽  
Nominal Stress ◽  
Stress Range ◽  
Fatigue Data ◽  
Range Parameter ◽  
Weld Fatigue ◽  
Curve Representation ◽  
The One

In this paper, some of the available duplex and super-duplex stainless steel umbilical tube fatigue data are analyzed using an equivalent nominal stress range parameter, which shares a great deal of similarity to the one used in the 2007 ASME Div 2 Code. The proposed fatigue parameter consists of nominal stress range, a size correction term RTt with RT being the tube radius and t being tube wall thickness, and a stress ratio term (1 − R) with R being applied stress ratio. With it, the available girth weld fatigue test data are shown to collapse into a narrow band. The equivalent nominal stress range parameter is also shown to be effective in correlating seam weld data collected from seam-welded umbilicals, but with a different slope in log-log based S-N plot. Coiling/uncoiling low-cycle effects can be addressed by introducing a pseudo elastic nominal stress definition. Miner’s rule can be used to combine both coiling/uncoiling effects with subsequent high-cycle fatigue loading.

Study on Reliability Assessment and Mechanics Behavior of Slab Culvert under Heavy Train

2011 ◽  
Vol 90-93 ◽  
pp. 1157-1161
Author(s):  
Qi Cai Wang ◽  
Rong Ling Zhang ◽  
Li Na Ma ◽  
You Xing Wei
Keyword(s):  
Fatigue Life ◽  
Corrosion Rate ◽  
Stress Analysis ◽  
Fatigue Test ◽  
Failure Probability ◽  
Reliability Assessment ◽  
Heavy Haul Train ◽  
Starting Point ◽  
Heavy Haul ◽  
Strain Stress

Abstract：The paper takes heavy haul train existing slab culvert disease and the research status for starting point, researches and analyzes the reliability assessment of slab culvert and fatigue test under heavy haul train. Different corrosion rate and reinforced section failure probability and reliable probability relations is researched as the emphasis . Strain-stress relations and slab culvert reinforced load are studied by the fatigue test , drawn the fatigue life of tensile steel. The research provides a reference for the stress analysis of slab culvert under the point supported conditions.

scholarly journals A Bayes Linear Bayes Method for Estimation of Correlated Event Rates

Risk Analysis ◽  
2013 ◽  
Vol 33 (12) ◽  
pp. 2209-2224 ◽  
Author(s):  
John Quigley ◽  
Kevin J. Wilson ◽  
Lesley Walls ◽  
Tim Bedford
Keyword(s):  
Bayes Method ◽  
Event Rates ◽  
Linear Bayes
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