1、Designator: Meta Bold 24/26Revision Note: Meta Black 14/16STP-NU-040UPDATE AND IMPROVE SUBSECTION NH SIMPLIFIED ELASTIC AND INELASTIC DESIGN ANALYSIS METHODSSTP-NU-040 UPDATE AND IMPROVE SUBSECTION NH SIMPLIFIED ELASTIC AND INELASTIC DESIGN ANALYSIS METHODS Prepared by: Jeries J. Abou-Hanna Douglas
2、L. Marriott Timothy E. McGreevy Advanced Consulting Engineering Services, Inc. Date of Issuance: October 19, 2012 This report was prepared as an account of work sponsored by the U.S. Department of Energy (DOE) and the ASME Standards Technology, LLC (ASME ST-LLC). This report was prepared as an accou
3、nt of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any in
4、formation, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endors
5、ement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Neither ASME, ASME ST-LLC, the authors nor others involved in
6、the preparation or review of this report, nor any of their respective employees, members or persons acting on their behalf, make any warranty, express or implied, or assume any legal liability or responsibility for the accuracy, completeness or usefulness of any information, apparatus, product or pr
7、ocess disclosed, or represents that its use would not infringe upon privately owned rights. Reference herein to any specific commercial product, process or service by trade name, trademark, manufacturer or otherwise does not necessarily constitute or imply its endorsement, recommendation or favoring
8、 by ASME ST-LLC or others involved in the preparation or review of this report, or any agency thereof. The views and opinions of the authors, contributors and reviewers of the report expressed herein do not necessarily reflect those of ASME ST-LLC or others involved in the preparation or review of t
9、his report, or any agency thereof. ASME ST-LLC does not take any position with respect to the validity of any patent rights asserted in connection with any items mentioned in this document, and does not undertake to insure anyone utilizing a publication against liability for infringement of any appl
10、icable Letters Patent, nor assumes any such liability. Users of a publication are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, is entirely their own responsibility. Participation by federal agency representative(s) or pe
11、rson(s) affiliated with industry is not to be interpreted as government or industry endorsement of this publication. ASME is the registered trademark of the American Society of Mechanical Engineers. No part of this document may be reproduced in any form, in an electronic retrieval system or otherwis
12、e, without the prior written permission of the publisher. ASME Standards Technology, LLC Three Park Avenue, New York, NY 10016-5990 ISBN No. 978-0-7918-3392-6 Copyright 2012 by ASME Standards Technology, LLC All Rights Reserved Update and Improve Subsection NH STP-NU-040 iii TABLE OF CONTENTS Forewo
13、rd . xi Abstract xii 1 SUBTASK 9.1 Outline of an “Ideal” High Temperature Code 1 Definition of “High Temperature” 1 1.1Design Loads and Failure Mechanisms to Consider . 2 1.2Design Criteria 3 1.3Design Evaluation . 6 1.41.4.1 Analysis 6 1.4.2 Testing 8 1.4.3 Surveillance 9 Material Properties Requir
14、ed to Perform a Design Assessment 9 1.5Documentation 10 1.6Conclusion . 10 1.72 SUBTASK 9.2 OBJECTIVE . 11 R5 11 2.12.1.1 R5 High Temperature 12 2.1.2 R5 Design Loads . 12 2.1.3 R5 Failure Mechanisms . 12 2.1.4 R5 Design Criteria/Procedures 13 Monju 27 2.22.2.1 Monju High Temperature 27 2.2.2 Monju
15、Design Loads . 28 2.2.3 Monju Failure Mechanisms . 29 2.2.4 Monju Design Criteria / Procedures 29 2.2.5 Monju Summary 30 RCC-MR . 45 2.32.3.1 RCC-MR High Temperature . 45 2.3.2 RCC-MR Design Loads 46 2.3.3 RCC-MR Failure Mechanisms 46 2.3.4 RCC-MR Design Criteria/Procedures . 47 ASME NH . 64 2.42.4.
16、1 ASME NH High Temperature . 66 2.4.2 ASME NH Design Loads 66 2.4.3 ASME NH - Failure Mechanisms 66 2.4.4 ASME NH Design Criteria / Procedures . 67 API579 80 2.52.5.1 API579 High Temperature 81 2.5.2 API579 Design Loads . 81 2.5.3 API579 Failure Mechanisms . 82 2.5.4 API579 Design Criteria / Procedu
17、res 83 Summary . 98 2.63 SUBTASK 9.3 OBJECTIVE . 99 Executive Summary 99 3.1Update and Improve Subsection NH STP-NU-040 iv 3.1.1 ASME NH Summary. 99 3.1.2 R5 Summary 101 3.1.3 RCC-MR Summary . 103 3.1.4 MONJU Summary . 104 3.1.5 API579 Summary 106 ASME NH . 109 3.23.2.1 Primary Load Limits 110 3.2.2
18、 Deformation Controlled Limits 112 R5 vs. ASME . 119 3.33.3.1 Primary Load Limits 120 3.3.2 Deformation Controlled Limits 126 RCC-MR vs. ASME 131 3.43.4.1 Primary Load Limits 132 3.4.2 Deformation Controlled Limits 133 3.4.3 Procedures for Analyzing Creep-Fatigue . 136 3.4.4 SUMMARY: 138 MONJU vs. A
19、SME 139 3.53.5.1 Primary Load Limits 139 3.5.2 Deformation Controlled Limits 140 3.5.3 Other Deformation Related Issues . 140 3.5.4 Material Properties . 141 API-579 vs. ASME 141 3.63.6.1 General Comments on API 579 141 3.6.2 Definition of “Elevated Temperature” . 141 3.6.3 Primary Load Limits 142 3
20、.6.4 Deformation Controlled Limits 142 3.6.5 Material Properties . 143 4 SUBTASK 9.4 OBJECTIVE . 144 Executive summary . 144 4.1A Historical Perspective of the Limit Load and Foundations of the ASME B suggestions are provided as to their relationship to one another. Except for brief descriptions, wh
21、ere these are needed for clarification, neither this subtask, nor the report as a whole, attempts to address details of the contents of all these elements. Some, namely primary load limits (elastic, limit load, reference stress), and ratcheting (elastic, e-p, reference stress) are dealt with specifi
22、cally in other subtasks of this report. All others are merely listed; the expectation is that they will either be the focus of attention of other active DOE-ASME GenIV Materials Tasks, e.g., creep-fatigue, or to be considered in future DOE-ASME GenIV Materials Tasks. Since the focus of this report i
23、s specifically approximate methods, the authors have deemed it necessary to include some discussion on what is meant by “approximate.” However, the topic will be addressed in one or more later subtasks. Definition of “High Temperature” 1.1“High temperature” is taken to refer here to the operating ra
24、nge of temperature within which time dependent, thermally activated deformation and damage processes, even under nominally steady loads below yield, become a significant factor in the behavior of load bearing components. This definition is commonly taken to mean the appearance of creep as a signific
25、ant mechanism, but others, such as thermal ageing and oxidation/corrosion are also important. In practice, time dependency is a smooth function of temperature. Consequently, there is no clear context free boundary separating time-independent from time-dependent behavior. For specific forms of servic
26、e conditions and material response, it is possible to define a temperature limit below which “high temperature” may be considered negligible in that the time dependent phenomena associated with high temperature behavior do not have a significant effect on design decisions. For the purpose of definin
27、g the applicability of a high temperature design Code, the threshold temperature marking the point above which time dependency first reaches significance is one valid criterion defining “high temperature” design. The threshold temperature is not unique. It is strictly a function of the mode of failu
28、re being considered, as well as the design lifetime. For instance, the threshold temperature for constant loading conditions, where stresses are expected to relax to a relatively low steady state, will be higher than one based on cyclic conditions which cause stresses to be repeatedly reset to the y
29、ield stress by cyclic plastic deformation. The specified design lifetime will also influence the Update and Improve Subsection NH STP-NU-040 2 threshold temperature. A higher value might be tolerated for short service lives compared with extended lifetimes. These are only the factors determining the
30、 importance of time dependent behavior in general. How these factors are implemented in a design Code is a decision to be made by the Code drafting body. All this report aims to do is list current practices or Code definitions. At one extreme, it is conceivable that the criterion for moving to a hig
31、h temperature Code could depend on whichever application specific failure mechanism yielded the lowest threshold temperature. For example, if the only condition seen by the component is steady loading, a higher limit might be permitted than if cyclic conditions were expected. A simpler but possibly
32、more conservative option is to select a single generic criterion based on the mechanism found to be the most conservative of all load cases covered by the Code, regardless of application. Finally, a Code might adopt a hybrid option, allowing less conservatism, at the cost of more effort to justify t
33、he use of a higher limit. A service life with limited period at elevated temperature, or a component with a short specified lifetime, might qualify for such treatment. Design Loads and Failure Mechanisms to Consider 1.2Design encompasses many aspects of system development and operation. This documen
34、t is restricted in its scope to criteria governing structural integrity or avoidance of mechanical failure due to structural collapse or material damage. “Load” is assumed here to include stress inducing forces and displacements from both mechanical and thermal sources. Failure mechanisms to be cons
35、idered in design for high temperature include the following. Firstly, failure mechanisms encountered in low temperature applications include: i. Limit load collapse, under a single load application. ii. Excessive displacement and/or deformation, limiting functionality, under a single load applicatio
36、n, below the limit load. iii. Structural instability or buckling, under a single load application. iv. Progressive collapse by ratcheting under cyclic load. v. Fracture by the initiation and/or propagation of a crack under a single load application. vi. Fatigue failure under cyclic loading. vii. Bre
37、ach of the pressure boundary, or structural collapse caused by corrosion induced loss of section. In addition to these, failure mechanisms specific to high temperature operation include viii. Creep rupture - loss of pressure boundary integrity due to a) the formation of local cracks, or b) general l
38、imit load collapse, due to creep induced continuum damage under essentially steady load. ix. Excessive deformation - loss of functionality, due to creep deformation under essentially steady load. x. Creep buckling - time dependent structural instability leading to catastrophic collapse or loss of fu
39、nction Update and Improve Subsection NH STP-NU-040 3 xi. Cyclically enhanced creep deformation - Accelerated creep deformation caused by repeated resetting of stresses by cyclic plastic strain, due to cyclic loads superimposed on a sustained load history. Also referred to as “creep ratcheting.” xii.
40、 Accelerated creep rupture - Accelerated creep damage caused by repeated resetting of stresses by cyclic plastic strain, due to cyclic loads superimposed on a sustained load history. xiii. Creep/fatigue interaction - Failure under cyclic conditions in a period, usually less than fatigue due to the c
41、yclic condition alone, or creep rupture due to time-at-stress alone, the mechanism for which may include other time/temperature related phenomena, such as oxide layer cracking and may be material specific. Finally, modifications to material properties may be influenced and suffer deterioration due t
42、o the following at all temperatures. xiv. Ageing induced by temperature, strain, radiation or diffusion leading to modification in any or all of the phenomena addressed in items i) through xiii) above. xv. Corrosion, oxidation and mass transfer phenomena. xvi. Irradiation induced failure mechanisms.
43、 Design Criteria 1.3An acceptable design is one which has a demonstrably acceptable resistance to the loadings listed in 1.2 above. This is done conventionally by comparing performance parameters of the component, based on understanding of its operating conditions, with allowable limits usually, but
44、 not always, based on material properties. An exception to this rule is, for instance, functional limitation due to excess deformation. In complex applications, such as those involving nonlinear or time dependent behavior, design criteria may call for consideration of both material properties and ge
45、ometrical factors simultaneously as, for instance, in the use of limit load concepts in evaluating primary load carrying capability. A major feature of all mechanical design Codes is a recognition that “stress” is not a sufficient basis for a failure criterion. Depending on the nature of the failure
46、 mechanism involved, the appropriate criterion may be only part of the total stress, or a function of the multiaxial stress state. Methods of stress classification are therefore an element which is present in all reputable Codes. A review of the structural concepts underlying the development of both
47、 design criteria and design evaluation methodologies is reserved for reporting in a later subtask. For current purposes, it is useful to refer frequently to one important classification, which is the distinction between “primary” stress, denoting that part of the total stress in equilibrium with ext
48、ernal mechanical forces, and “secondary” stress, which consists of all contributions to an internal, self equilibrating or residual stress state. The former is instrumental in causing gross structural collapse whereas the latter is only of concern in situations of cyclic load or local damage accumul
49、ation. With this qualification in mind, the following criteria correspond approximately to the load cases listed in the previous section. i. Limit Load A minimum requirement of any component is that it be able to support a single application of the worst combination of all the static loads to which it is subjected. This may be achieved conservatively by limiting service stresses or, in components constructed from ductile materials, by ensuring that Update and Improve Subsection NH STP-NU-040 4 the collapse load exceeds the maxi
