scholarly journals Assessing the ASME Section III, Division 5, Class A Primary Load Design Rules Against Creep Notch Effects

2021 ◽  
Author(s):  
Guosheng Ye ◽  
Mark Messner
Keyword(s):  
Design Rules ◽  
Class A ◽  
Primary Load

A Probabilistic Margin Assessment of the ASME Section III, Division 5 Primary Load Design Rules for Class A Components

2021 ◽  
Author(s):  
Andrea Nicolas ◽  
Mark C. Messner ◽  
T.-L. Sham
Keyword(s):  
Monte Carlo ◽  
Steady State ◽  
Material Strength ◽  
Margin Assessment ◽  
Design Rules ◽  
Monte Carlo Approach ◽  
Class A ◽  
Wide Range ◽  
Primary Load ◽  
Design Margin

Abstract This work presents a comprehensive probabilistic margin assessment of the ASME BPVC primary load design rules for Class A components in Section III Division 5. This work evaluates the design margin of several of the Class A materials for a simple, but representative, component geometry across the entire Division 5 elevated temperature range. The margin assessment applies a probabilistic life prediction methodology developed in previous work that accounts for the variability in material strength and deformation. A Gaussian process fit captures the the strength variability, and a Monte Carlo approach accounts for the variability of steady-state creep deformation parameters leading to variability in the stresses developed in a component. A very efficient method based on the analogy between very viscous Stokes flow to steady-state creeping solid determines the steady-state stress distribution under primary load for the Monte Carlo approach. This work is therefore capable of efficiently evaluating the design margin of several materials across a wide range of temperatures. The probabilistic margin assessment presented in this work gives an insight into the design margin in the currently deterministic ASME Section III, Division 5 primary load design rules for high temperature nuclear components.

Design Methodologies for High Temperature Reactor Structural Components Cladded With Noncompliant Materials

2019 ◽  
Author(s):  
B. Barua ◽  
V.-T. Phan ◽  
M. C. Messner ◽  
B. Jetter ◽  
T.-L. Sham ◽  
...  
Keyword(s):  
High Temperature ◽  
Base Material ◽  
Design Rules ◽  
Corrosion Resistant ◽  
Class A ◽  
Creep Fatigue ◽  
The Difference ◽  
Near Term ◽  
Term Creep

Abstract The existing Class A metallic materials qualified for ASME Section III, Division 5 rules for high temperature nuclear reactors, are not optimized for corrosion resistance when exposed to corrosive reactor coolants such as molten salts, and molten lead and lead-bismuth eutectic. Introducing new corrosion-resistant materials into the Code would be a lengthy and expensive process for long design lifetimes, requiring long-term creep test data. A near-term alternative solution might be to allow designers to clad the existing Class A materials with thin layer of some corrosion-resistant material. However, the current ASME Section III, Division 5 rules provide no guidance on evaluating cladded components against the Code creep-fatigue or strain limits requirements. This necessitates the development of design rules for cladded components that do not require long-term testing of clad materials. Depending on the difference in mechanical properties, the influence of clad on the long term response of the structural system can be significant or negligible. This work focuses on developing design rules for cladded components with a clad material that does not accumulate significant inelastic deformation compared to the base material. This work proposes to treat such clad materials as linear elastic. Sample calculations including finite element analyses of a representative molten salt reactor heat exchanger tube without and with clad were performed to verify the proposed approach. Finally, a complete set of design rules for components with noncompliant clad material is proposed.

Development of Design Method for High Temperature Nuclear Reactor Cladded Components

2020 ◽  
Author(s):  
B. Barua ◽  
M. C. Messner ◽  
R. I. Jetter ◽  
T.-L. Sham
Keyword(s):  
High Temperature ◽  
Nuclear Reactor ◽  
Nuclear Reactors ◽  
Design Method ◽  
Base Material ◽  
Approximate Design ◽  
Design Rules ◽  
Corrosion Resistant ◽  
Class A

Abstract High temperature nuclear reactors plan to use highly corrosive coolant such as molten salts, molten lead, and lead-bismuth eutectic mixtures. The existing Class A metallic materials qualified in the ASME Section III, Division 5 rules for high temperature nuclear reactors are not ideal for resisting corrosion when exposed to these coolants. One option to overcome this limitation would be to Code-qualify new corrosion-resistant materials for Class A service, however this process is long and expensive and requires long-term creep test data. A near-term alternative would be to allow designers to clad the existing Class A base materials with non-qualified corrosion-resistant materials. However, there are currently no ASME design rules for cladded components to guard against creepfatigue failure and ratcheting strain accumulation in elevated temperature nuclear service. This work addresses this deficiency by proposing a design strategy for cladded components that does not require long-term testing of clad materials. The proposed approach relies on approximate design analysis methods for two types of clad materials — soft clad that creeps faster than the base material and hard clad that creeps slower and has higher yield stress than the base material. The proposed approach treats a soft clad material as perfectly compliant and a hard clad material as linear elastic. Sample finite element analyses of representative high temperature reactor components are performed to verify the approach. At the end, a complete set of design rules is provided for each of the two types of cladded components.

Important Compounds in the Cocaine Class: A Synthesis Overview

1991 ◽  
Author(s):  
F.I. Carroll ◽  
◽  
Anita H. Lewin
Keyword(s):  
Class A

Contrasting underlying mechanisms of different barrier coating types

TAPPI Journal ◽  
2018 ◽  
Vol 17 (01) ◽  
pp. 31-37
Author(s):  
Bryan McCulloch ◽  
John Roper ◽  
Kaitlin Rosen
Keyword(s):  
Food Packaging ◽  
Underlying Mechanism ◽  
Consumer Products ◽  
Mechanical Degradation ◽  
Design Rules ◽  
Barrier Coatings ◽  
Barrier Materials ◽  
Barrier Coating ◽  
Coating Type ◽  
Underlying Mechanisms

Barrier coatings are used in applications including food packaging, dry goods, and consumer products to prevent transport of different compounds either through or into paper and paperboard substrates. These coatings are useful in packaging to contain active ingredients, such as fragrances, or to protect contents from detrimental substances, such as oxygen, water, grease, or other chemicals of concern. They also are used to prevent visual changes or mechanical degradation that might occur if the paper becomes saturated. The performance and underlying mechanism depends on the barrier coating type and, in particular, on whether the barrier coating is designed to prevent diffusive or capillary transport. Estimates on the basis of fundamental transport phenomena and data from a broad screening of different barrier materials can be used to understand the limits of various approaches to construct barrier coatings. These estimates also can be used to create basic design rules for general classes of barrier coatings.

DISTRIBUIÇÃO DA EVAPORAÇÃO EM ESTUFA PLÁSTICA NA PRIMAVERA

Irriga ◽  
2001 ◽  
Vol 6 (3) ◽  
pp. 120-127
Author(s):  
Reginaldo Ferreira Santos ◽  
Antonio Evaldo Klar
Keyword(s):  
Spatial Variability ◽  
Pan Evaporation ◽  
Spring Season ◽  
Class A ◽  
Agricultural Sciences ◽  
E Mail ◽  
Center Area ◽  
Class A Pan

DISTRIBUIÇÃO DA EVAPORAÇÃO EM ESTUFA PLÁSTICA NA PRIMAVERA  Reginaldo Ferreira SantosCentro de Ciências Exatas e Tecnológica da UNIOESTE- CP 711CEP 858114-110, Cascavel, PR - Fone: 0XX45 2203155.  E-mail: [email protected] Evaldo KlarDepartamento de Engenharia Rural - Faculdade de Ciências Agronômica- UNESP - CEP 18603-970 - Botucatu, SP. CP: 237.  E-mail:  [email protected]  1  RESUMO O presente trabalho teve como objetivo avaliar a distribuição da evaporação no interior de uma estufa plástica, com uma cultura de pimentão, através da variabilidade espacial e comparar a evaporação dos microevaporímetros com os valores do Tanque classe "A". O experimento foi conduzido no Campus da Universidade Estadual Paulista - FCA/UNESP, no período de primavera, em estufa plástica de polietileno de baixa densidade (PEBD). Na distribuição da evaporação em estufa com orientação norte/sul, verificou-se que as maiores evaporações ocorreram nas extremidades sul e norte tendente ao lado oeste. Já as menores evaporações localizaram-se no centro. No período de primavera, a evaporação média nos microevaporímetros superestimou em 55% a evaporação determinada no Tanque classe "A". UNITERMOS: evaporação, geoestatística, estufa.  SANTOS, R.F, KLAR, A.E.  EVAPORATION DISTRIBUTION INSIDE A PLASTIC TUNNEL IN THE SPRING SEASON  2  ABSTRACT                 The main aim of this study was to verify the evaporation distribution inside a plastic tunnel, with pepper crop, oriented to north/south, through spatial variability and to compare Class A Pan evaporation to punctual evaporations of 40 equidistant microevaporimeters placed from 50cm the soil. The study was carried out at the College of Agricultural Sciences/UNESP, Botucatu – SP in the spring season.  The highest evaporation occurred next to north and to south sides of the tunnel, with tendency to west. Consequently, the lowest evaporations occurred at the center area. The microevaporimeter evaporations were 55% higher than those obtained from Class A Pan. KEYWORDS: evaporation distribution, microevaporimeter.

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