A Thermal Stress Evaluation Procedure for Monolithic Annealed Glass

2009 ◽  
pp. 105-105-14
Author(s):  
WL Beason ◽  
AW Lingnell
Keyword(s):  
Thermal Stress ◽  
Evaluation Procedure ◽  
Stress Evaluation ◽  
Annealed Glass

Flow features and thermal stress evaluation in turbulent mixing flows

2021 ◽  
Vol 178 ◽  
pp. 121605
Author(s):  
Cenk Evrim ◽  
Xu Chu ◽  
Fabian E. Silber ◽  
Alexander Isaev ◽  
Stefan Weihe ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Turbulent Mixing ◽  
Stress Evaluation ◽  
Flow Features

2801 Thermal stress evaluation for branch with closed end

2007 ◽  
Vol 2007.1 (0) ◽  
pp. 677-678
Author(s):  
Toru OUMAYA ◽  
Akira NAKAMURA ◽  
Nobuyuki TAKENAKA
Keyword(s):  
Thermal Stress ◽  
Stress Evaluation

Evaluation of Thermal Stress Ratchet in Plastic FEA

2002 ◽  
Author(s):  
Yukinori Yamamoto ◽  
Norimichi Yamashita ◽  
Masaaki Tanaka
Keyword(s):  
Finite Element ◽  
Thermal Stress ◽  
Stress State ◽  
Plastic Strain ◽  
Axial Stress ◽  
Equivalent Plastic Strain ◽  
Hardening Material ◽  
Linear Temperature ◽  
Stress Evaluation ◽  
Elastic Core

Alternative stress evaluation criteria suitable for Finite Element Analysis (FEA) proposed by Okamoto et al. [1] have been studied by the Committee on Three Dimensional Finite Element Stress Evaluation (C-TDF) in Japan. Thermal stress ratchet criteria in plastic FEA are now under consideration. Two criteria are proposed: evaluating variations in plastic strain increments and evaluating variations in the width of elastic core. To verify the validity of these criteria, calculations were performed for several typical models in C-TDF [2]. This paper shows the results of a simple cylinder model. Cyclic plastic analyses were performed applying sustained internal pressure and alternating linear temperature distribution through the wall. Analyses were performed with various load ranges to evaluate the precise ratchet limit and its behavior across the limit. Both pressure and thermal stress were given parameters. In the analyses, Elastic-Perfectly-Plastic (EPP) material was used and also strain hardening material for comparison. The ratchet limit in the Code [3] is based on Miller’s theoretical analysis [4] for a cylinder assuming a uni-axial stress state, whereas real vessels are in multi-axial stress state. By our calculations, we also examined the ratchet limit in real vessels. The results show that for the cylinder in a multi-axial stress state, the ratchet limit rises 1.2 times the ratchet limit by the Code. The evaluation results show that variations in equivalent plastic strain increments can be used for ratchet criterion and ratcheting can be assessed by confirming the presence of elastic core in the second cycle.

Simplified Primary Stress Evaluation Procedure for Thinned Class 1 Piping Elbow

2007 ◽  
Author(s):  
R. Balakrishnan ◽  
San Iyer
Keyword(s):  
Limit Load ◽  
Evaluation Procedure ◽  
Element Analysis ◽  
Stress Evaluation ◽  
Primary Stress ◽  
Inelastic Analysis ◽  
Class 1 ◽  
Alternate Procedure ◽  
Distribution Of Stress ◽  
Stress Criteria

Inelastic finite element analysis offers an alternate procedure to evaluate damaged piping components for their fitness-for-service purposes. Redistribution of stress resultants beyond yield taken into account in a typical inelastic analysis becomes significant as a damaged piping component may not satisfy code stress criteria based on elastic analysis. A complete inelastic analysis to estimate the limit load of the component may be a numerically intensive and cumbersome process. This paper involves a two step analytical process — unloading a component to satisfy code stress categories after a prior plastic distribution of stress resultants is setup in the component. Linearization of stresses in the thinned section has shown reduction in the general membrane and membrane plus bending stress intensities when analyzed using this simplified method. To illustrate the method, an analysis is performed on both thick and thin pipe with local thinning.

Uncertainties of the Evaluation of the Hole Drilling Residual Stress Measurement According to the ASTM E837 Standard

2015 ◽  
Vol 732 ◽  
pp. 24-27 ◽  
Author(s):  
Michal Švantner ◽  
Jiří Skála
Keyword(s):  
Residual Stress ◽  
Stress Measurement ◽  
Residual Stress Measurement ◽  
Evaluation Procedure ◽  
Hole Drilling ◽  
Basic Principles ◽  
Stress Evaluation ◽  
Integral Methods ◽  
Measurement And Evaluation ◽  
Astm E837

The paper deals in hole drilling residual stress measurement method. The basic principles of measurement and evaluation by the uniform stress and Integral methods are described. The uncertainties of the residual stress evaluation procedure based on the ASTM E837 standard are analyzed. Examples of residual stress evaluation and comparison of different ASTM E837 standard editions are presented.

Effects of Bending Moment and Torsion on the Internal Pressure Limit Load of Locally Thinned Pipes

2011 ◽  
Author(s):  
Phuong H. Hoang ◽  
Kunio Hasegawa ◽  
Bostjan Bezensek ◽  
Yinsheng Li
Keyword(s):  
Internal Pressure ◽  
Pipe Wall ◽  
Large Strain ◽  
Bending Moment ◽  
Limit Load ◽  
Evaluation Procedure ◽  
Structural Factors ◽  
Stress Evaluation ◽  
Pressure Limit ◽  
Wall Thinning

The pipe wall thinning stress evaluation procedures in Code-Case N-597-2 [1] of the ASME Boiler and Pressure Vessel (B&PV) Code are essentially based on Construction Code [2] stress evaluation. Stresses in the hoop and the axial directions are evaluated separately to meet the Construction Code allowable stress. Using Construction Code rules for local pipe wall thinning stress evaluation in Class 2 & 3 piping may be too restrictive. An alternative approach is to use the limit loads of locally wall thinned pipe in conjunction with an appropriate Z-Factor and the structural factors of the ASME B&PV Section XI, Appendix C [3]. Such approach may require a combined effect of pressure, bending, axial load and torsion loads on locally thinned pipe. In this paper, the effects of bending moment and torsion on the internal pressure limit load of locally thinned straight pipes are investigated. Large strain finite element limit load analysis with elastic - perfectly plastic materials are performed for a parametric matrix of piping models with various pipe R/t ratios, flaw depths, axial and transverse flaw extents. Based on the results, the allowable pressure for axial flaws in C-5420 of the ASME B&PV Section XI, Appendix C [3] may be used for piping local wall thinning as an alternative evaluation procedure to the current minimum pipe wall thickness evaluation procedure in the Code Case N-597-2 [1].

A Study on Thermal Stress Evaluation of Safety Injection System for NPPs Considering Leakage Effect

2011 ◽  
Author(s):  
Hee-Dong Sung ◽  
Sun-Hye Kim ◽  
Ik-Joong Kim ◽  
Young-Jin Kim ◽  
Jeong-Soon Park ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Thermal Stratification ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Injection System ◽  
Stress Evaluation ◽  
Branch Line ◽  
Leakage Model ◽  
Cfd Analyses

Several piping failures caused by thermal stratification have been reported in some nuclear power plants since the early 1980s. However, this kind of thermal effect was not considered when the old vintage nuclear power plants were designed. Thermal stratification is usually generated by turbulent penetration from the RCS to branch line or leakage through damaged part of valve in branch line. In this paper, using the CFD analysis, characteristics of thermal stratification in a safety injection system of PWR plant were investigated and thermal stress evaluation was also conducted. First, CFD analyses were carried out on in-leakage model and out-leakage model according to operating condition. The case of out-leakage, the thermal stratification based on temperature distribution was generated a little at the rear of 1st valve. In contrast, significant thermal stratification was generated in front of 1st valve in in-leakage model because the effect of rapid flow velocity from RCS.

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