Design Rules for Ratcheting Damage in AFCEN RCC-MRX 2012 Code

2014 ◽  
Author(s):  
P. Lamagnère ◽  
Y. Lejeail ◽  
C. Petesch ◽  
T. Lebarbé ◽  
P. Matheron ◽  
...  
Keyword(s):  
Austenitic Stainless Steels ◽  
Creep Damage ◽  
Cyclic Strain ◽  
Design Rule ◽  
Seismic Load ◽  
Thermal Gradients ◽  
Design Rules ◽  
Primary Stress ◽  
French And English ◽  
Secondary Membrane

The paper describes the design rules for ratcheting in the 2012 edition of the RCC-MRx Code issued in French and English versions by AFCEN (French Association for the rules governing the Design, Construction and Operating Supervision of the Equipment Items for Electro Nuclear Boilers). For austenitic stainless steels, the RCC-MRx Code uses the efficiency diagram concept to evaluate an effective primary stress, Peff. Peff is defined as a virtual stress that applied alone would cause the same strain as the combination of the primary static stress and the secondary cyclic strain really applied. This concept is extended to significant creep domain and includes corrections to take into account structures cases presenting secondary membrane stresses (e.g. cylinders subjected to axial thermal gradients varying with time and space) or short duration overloads (as a level A seismic load, or an overload due to rapid drain-out caused by a sodium-water reaction). An alternative 3Sm design rule is proposed for all materials in the case of non-significant creep damage.

Consideration of Creep in Design Rules of AFCEN RCC-MRx 2012 Code

2013 ◽  
Author(s):  
T. Lebarbé ◽  
C. Petesch ◽  
Y. Lejeail ◽  
P. Lamagnère ◽  
S. Dubiez-Le Goff
Keyword(s):  
High Temperature ◽  
Research Reactor ◽  
Creep Damage ◽  
Vacuum Vessel ◽  
Design Rules ◽  
French And English ◽  
Type Of Exercise ◽  
Set Up

The 2012 edition of the RCC-MRx Code has been issued in French and English versions by AFCEN (Association Française pour les règles de Conception et de Construction des Matériels des Chaudières Electro-nucléaires). This Code is the result of the merger of the RCC-MX 2008 developed in the context of the research reactor Jules Horowitz Reactor project, in the RCC-MR 2007 which set up rules applicable to the design of components operating at high temperature and to the Vacuum Vessel of ITER. This new edition is the opportunity to publish also the background of the rules. This paper is one illustration of what may be such a document, on a dedicated example, the creep rules. It contains an overview of the design rules associated to the creep damage and explains the purpose and the origins of these rules. This type of exercise is going to be generalized to all the parts of the code in AFCEN technical publications, the criteria.

Effect of Cyclic Strain-Hardening Exponent on Fatigue Ductility Exponent for Sn Based Alloy

2011 ◽  
Author(s):  
Yoshihiko Kanda ◽  
Yuji Oto ◽  
Yusuke Shiigi ◽  
Yoshiharu Kariya
Keyword(s):  
Solid Solution ◽  
Strain Hardening ◽  
Creep Damage ◽  
Cyclic Strain ◽  
Damage Mechanism ◽  
Strain Hardening Exponent ◽  
Large Size ◽  
Grain Boundary Fracture ◽  
Boundary Fracture ◽  
Compound Particle

The influence of cyclic strain-hardening exponents on fatigue ductility exponents for Sn-Bi solid solution alloys and Sn-Ag-Cu microsolder joints was investigated. In Sn-Bi solid solution alloys, the fatigue ductility exponent in Coffin-Manson’s law was confirmed to increase with a decrease in the cyclic strain-hardening exponent. On the other hand, in the Sn-Ag-Cu miniature solder joint, the fatigue ductility exponent increases with a rise in temperature and strain holding. Thus, the fatigue ductility exponents are closely related to the cyclic strain-hardening exponent: the former increases due to the depression of the latter with a rise in temperature and increase in intermetallic compound particle size during strain holding. The results differ for the creep damage mechanism (grain boundary fracture), which is the main reason for the life depression in large-size specimens.

Overview of Proposed High Temperature Design Code Cases

2016 ◽  
Author(s):  
Peter Carter ◽  
T.-L. (Sam) Sham ◽  
Robert I. Jetter
Keyword(s):  
High Temperature ◽  
Yield Stress ◽  
Creep Damage ◽  
Cyclic Strain ◽  
Inelastic Strain ◽  
Cyclic Creep ◽  
Strain Accumulation ◽  
Temperature Dependent ◽  
Common Basis ◽  
Creep Fatigue

Proposals for high temperature design methods have been developed for primary loads, creep-fatigue and strain limits. The methodologies rely on a common basis and assumption, that elastic, perfectly plastic analysis based on appropriate properties reflects the ability of loads and stress to redistribute for steady and cyclic loading for high temperature as well as for conventional design. The cyclic load design analyses rely on a further key property, that a cyclic elastic-plastic solution provides an upper bound to displacements, strains and local damage rates. The primary load analysis ensures that the design load is in equilibrium with the code allowable stress, taking into account: i) The stress state dependent (multi-axial) rupture criterion, ii) The limit to stress re-distribution defined by the material creep law. The creep-fatigue analysis is focused on the cyclic creep damage calculation, and uses conventional fatigue and creep-fatigue damage calculations. It uses a temperature-dependent pseudo “yield” stress defined by the material yield and rupture data to identify cycles which will not cause creep damage > 1 for the selected life. Similarly the strain limits analysis bounds cyclic strain accumulation. It also uses a temperature-dependent pseudo “yield” stress defined by the material yield and creep strain accumulation data to identify cycles which will not cause average (membrane) inelastic strain > 1% for the design life. The paper gives an overview of the background and justification of these statements, and examples.

scholarly journals Hardware Design Rule Checker Using a CAM Architecture

VLSI Design ◽  
1996 ◽  
Vol 4 (2) ◽  
pp. 141-147
Author(s):  
Seokjin Kim ◽  
Ramalingam Sridhar
Keyword(s):  
Pattern Matching ◽  
Input Data ◽  
Hardware Implementation ◽  
Low Cost ◽  
Design Rule ◽  
Design Rules ◽  
One Dimensional ◽  
Content Addressable Memory ◽  
Logic Operations ◽  
Geometric Designs

This paper presents a hardware implementation of design rule checker using a specialized Content Addressable Memory(CAM) for the Manhattan geometric designs. Two dimensional relationships between rectangular objects in a design are checked with one dimensional design rules. The input data is processed by the pixel pre-processor in such a way that direct comparison between the input data and the stored rules in the CAM is possible. The comparison by the CAM reduces the number of memory references and logic operations of pattern matching and the simple architecture of the system enables a low cost implementation.

Limit States Design for Onshore Pipelines: Designing for Hydrostatic Test Pressure and Restrained Thermal Expansion

2014 ◽  
Author(s):  
Riski H. Adianto ◽  
Maher A. Nessim
Keyword(s):  
Thermal Expansion ◽  
Input Parameter ◽  
Local Buckling ◽  
Companion Paper ◽  
Design Rule ◽  
Material Strength ◽  
Safety Factors ◽  
Limit States ◽  
Design Rules ◽  
Test Pressure

Reliability-based design rules have been developed for the key serviceability limit states applicable to onshore pipeline including local buckling due to thermal expansion and excessive plastic deformation under hydrostatic test pressure. The design rules are characterized by three elements: the formulas used to calculate the characteristic demand and capacity; the criteria used to define the characteristic values of the key input parameters to these formulas (such as diameter and material strength); and the safety factors defining the required excess capacity over the demand. The overall methodology used in developing the design rules and the practical implications of applying them are described in a companion paper. This paper describes the process used to calibrate safety factors and characteristic input parameter values that meet the desired reliability levels. The results show that local buckling under restrained thermal expansion is only potentially relevant for a small sub-set of cases and based on this, an explicit design rule was not developed. For excessive deformation under hydrostatic test pressure, two alternate design rules are provided; one stress based and the other strain based. The final design rules are described and an assessment of their accuracy and consistency in meeting the reliability targets is included. Guidance is also provided on the conditions in which each check is used.

New Common Design Rules for U-Tube Heat Exchangers in ASME, CODAP and UPV Codes

2002 ◽  
Author(s):  
F. Osweiller
Keyword(s):  
Heat Exchangers ◽  
Pressure Vessels ◽  
Design Rule ◽  
Technical Approach ◽  
Design Rules ◽  
Asme Code ◽  
European Code ◽  
Section Viii ◽  
Technical Basis ◽  
Year 2000

In year 2000, ASME Code (Section VIII – Div. 1), CODAP (French Code) and UPV (European Code for Unfired Pressure Vessels) have adopted the same rules for the design of U-tube tubesheet heat exchangers. Three different rules are proposed, based on different technical basis, to cover: • Tubesheet gasketed with shell and channel. • Tubesheet integral with shell and channel. • Tubesheet integral with shell and gasketed with channel or the reverse. At the initiative of the author, a more refined technical approach has been developed, to cover all tubesheet configurations. The paper explains the rationale for this new design rule which is being incorporated in ASME, CODAP and UPV in 2002. This is substantiated with comparisons to TEMA Standards and a benchmark of numerical comparisons.

Cycle-Dependent and Time-Dependent Bone Fracture With Repeated Loading

1983 ◽  
Vol 105 (2) ◽  
pp. 166-170 ◽  
Author(s):  
D. R. Carter ◽  
W. E. Caler
Keyword(s):  
Low Cycle Fatigue ◽  
Strain Range ◽  
Creep Damage ◽  
Cyclic Strain ◽  
Fatigue Tests ◽  
Time Dependent ◽  
Tensile Creep ◽  
Repeated Loading ◽  
Time To Failure ◽  
Creep Fracture

Fatigue tests of human cortical bone (up to 1.74 × 106 cycles) were conducted under tension-compression (T-C) and zero-tension (O-T) modes with a 2Hz, stress controlled, sinusoidal loading history. Tensile creep-fracture tests at constant stress levels were also performed. The relationship between the initial cyclic strain range and cycles to failure with the T-C specimens were consistent with that derived previously in low-cycle fatigue under strain control. Using a time-dependent failure model, the creep-fracture data was found to be consistent with previous studies of the influence of strain rate on the monotonic tensile strength of bone. The model also predicted quite well the time to failure for the O-T fatigue specimens, suggesting that creep damage plays an important role in O-T fatigue specimens.

Analysis of the Stress Basis to Use for Creep Evaluation of Pipelines in Fitness-for-Service Assessments

2013 ◽  
Author(s):  
Lorenzo Scano
Keyword(s):  
High Pressures ◽  
Creep Damage ◽  
High Energy ◽  
Fe Model ◽  
Primary Stress ◽  
Creep Stress ◽  
Expansion Range ◽  
Level 3 ◽  
Very High ◽  
Time Dependent Analysis

High-energy pipelines are operated at very high pressures and temperatures, with a typical lifetime in the order of decades. Therefore, FFS assessments are periodically performed to evaluate piping safety against creep. Major design codes provide allowable stresses in the creep range; nevertheless, an actual stress basis is needed to calculate creep damage in a FFS procedure. In this paper, three stress bases were considered: the first one includes the primary circumferential and axial stresses, taking also into account the pressure inelastic redistribution. The second basis includes primary hoop and sustained code stresses. Finally, the third one considers EN13480 axial creep stress, including one third of the secondary expansion range. The stress bases were calculated for an example pipeline through a standard stress analysis and the API 579-1 standard was used to evaluate piping safe life. An inelastic, time-dependent analysis of the pipeline, including plasticity and creep, was then carried out via a shell FE model and the lifetime computed using a Level 3 procedure. The comparison between the investigations showed that the primary stress bases were non-conservative for creep evaluation. The combined primary and secondary stress basis led instead to a lifetime consistent with that calculated through the Level 3 procedure.

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