Study on a New Design Fatigue Evaluation Method

2015 ◽  
Author(s):  
Seiji Asada ◽  
Takashi Hirano ◽  
Takehiko Sera
Keyword(s):  
Evaluation Method ◽  
Austenitic Stainless Steels ◽  
Carbon Steels ◽  
Design Evaluation ◽  
Low Alloy Steels ◽  
Mean Stress ◽  
Research Committee ◽  
Fatigue Design ◽  
Fatigue Evaluation ◽  
Design Factors

In order to develop new design fatigue curves for austenitic stainless steels, carbon steels and low alloy steels and a new design fatigue evaluation method that is rational and has a clear design basis, the Design Fatigue Curve (DFC) subcommittee was established in the Atomic Energy Research Committee in the Japan Welding Engineering Society. Tentative design fatigue curves were developed and studies on the effects of mean stress and design factors are ongoing. Design fatigue curves, including the effects of mean stress and design factors, are needed to establish a new fatigue design evaluation method. This paper describes the study on the new fatigue design evaluation method.

Study on Mean Stress Effects for Design Fatigue Curves

2016 ◽  
Author(s):  
Seiji Asada ◽  
Takeshi Ogawa ◽  
Makoto Higuchi ◽  
Hiroshi Kanasaki ◽  
Yasukazu Takada
Keyword(s):  
Evaluation Method ◽  
Austenitic Stainless Steels ◽  
Fatigue Curve ◽  
Carbon Steels ◽  
Low Alloy Steels ◽  
Mean Stress ◽  
Research Committee ◽  
Stress Effects ◽  
Alloy Steels ◽  
Design Factors

In order to develop new design fatigue curves for austenitic stainless steels, carbon steels and low alloy steels and a new design fatigue evaluation method that are rational and have a clear design basis, the Design Fatigue Curve (DFC) subcommittee was established in the Atomic Energy Research Committee in the Japan Welding Engineering Society. Mean stress effects for design fatigue curves are to be considered in the development of design fatigue curves. The Modified Goodman approach for mean stress effects is used in the design fatigue curves of the ASME B&PV Code. Tentative design fatigue curves were developed and studies on the effect of mean stress and design factors are on-going. Development of design fatigue curves, effect of mean stress and design factors is needed to establish a new fatigue design evaluation method. The DFC subcommittee has studied correction approaches for mean stress effects and the approaches of modified Goodman, Gerber, Peterson and Smith-Watson-Topper were compared using test data in literature. An appropriate approach for mean stress effects are discussed in this paper.

Development of New Design Fatigue Curves in Japan: Proposal of a New Fatigue Evaluation Method

2018 ◽  
Author(s):  
Seiji Asada ◽  
Akihiko Hirano ◽  
Toshiyuki Saito ◽  
Yasukazu Takada ◽  
Hideo Kobayashi
Keyword(s):  
Stainless Steels ◽  
Evaluation Method ◽  
Austenitic Stainless Steels ◽  
Fatigue Tests ◽  
Carbon Steels ◽  
Low Alloy Steels ◽  
Stress Effect ◽  
Fatigue Data ◽  
Alloy Steels ◽  
Fatigue Evaluation

In order to develop new design fatigue curves for carbon steels & low-alloy steels and austenitic stainless steels and a new design fatigue evaluation method that are rational and have clear design basis, Design Fatigue Curve (DFC) Phase 1 subcommittee and Phase 2 subcommittee were established in the Atomic Energy Research Committee in the Japan Welding Engineering Society (JWES). The study on design fatigue curves was actively performed in the subcommittees. In the subcommittees, domestic and foreign fatigue data of small test specimens in air were collected and a comprehensive fatigue database (≈6000 data) was constructed and the accurate best-fit curves of carbon steels & low-alloy steels and austenitic stainless steels were developed. Design factors were investigated. Also, a Japanese utility collaborative project performed large scale fatigue tests using austenitic stainless steel piping and low-alloy steel flat plates as well as fatigue tests using small specimens to obtain not only basic data but also fatigue data of mean stress effect, surface finish effect and size effect. Those test results were provided to the subcommittee and utilized the above studies. Based on the above studies, a new fatigue evaluation method has been developed.

Environmental Fatigue Evaluation for Interface of Dissimilar Metal Welded Piping

2017 ◽  
Author(s):  
Dae Geon Lee ◽  
Dae Soo Kim ◽  
Kyeong Jin Yang ◽  
Joon Ho Lee ◽  
Seong Cheol Jang
Keyword(s):  
Evaluation Method ◽  
Austenitic Stainless Steels ◽  
Carbon Steels ◽  
Nuclear Industry ◽  
Low Alloy Steels ◽  
Plant Design ◽  
Dissimilar Metal ◽  
Dissimilar Metal Welding ◽  
Fatigue Evaluation ◽  
Metal Welding

Environmental fatigue evaluation is a key technology to extend Nuclear Power Plant design life. Since USNRC issued the RG 1.207 in 2007, many studies on fatigue evaluation in Light water Reactor coolant environments have been carried out by referencing documents such as NUREG/CR-6909, EPRI-TR-1025823, ASME BPVC Sec. III NB-3600/3200 Code, ASME Code Case, and so on. These documents presented environmental fatigue evaluation methods about each single-metal such as carbon steels, low-alloy steels, nickel-chromium-iron (Ni-Cr-Fe) alloys, and austenitic stainless steels. However, the environmental fatigue evaluation method for interface of dissimilar metal welding is mostly insufficient. Dissimilar metal welding has been widely used in nuclear industry. If environmental fatigue analysis method for dissimilar metal welding is developed, it will facilitate the design of piping for more safety. Therefore, the development of environmental fatigue evaluation for the interface of dissimilar metal welding should be studied. This paper presents environmental fatigue evaluation for the interface of dissimilar metal welded piping. The environmental fatigue evaluation for a dissimilar metal welded piping model was performed based on above documents.

Plan and Status of Development of Design Fatigue Curves: Phase 1

2013 ◽  
Author(s):  
Seiji Asada ◽  
Akihiko Hirano ◽  
Masao Itatani ◽  
Munehiro Yasuda ◽  
Takehiko Sera ◽  
...  
Keyword(s):  
Stainless Steels ◽  
Phase 1 ◽  
Austenitic Stainless Steels ◽  
Fatigue Curve ◽  
Carbon Steels ◽  
Low Alloy Steels ◽  
Energy Research ◽  
Research Committee ◽  
Engineering Society ◽  
Alloy Steels

In order to develop and propose new design fatigue curves for austenitic stainless steels, carbon steels and low alloy steels that are rational and have clear design basis, Design Fatigue Curve (DFC) subcommittee has been established in the Atomic Energy Research Committee in the Japan Welding Engineering Society and the study on design fatigue curves are going on. This paper introduces the plan and status of the activities of the DFC subcommittee.

scholarly journals Development of a Water Environment Fatigue Design Curve for Austenitic Stainless Steels

2003 ◽  
Author(s):  
Thomas R. Leax
Keyword(s):  
Stainless Steels ◽  
Fatigue Behavior ◽  
Water Environment ◽  
Austenitic Stainless Steels ◽  
Fatigue Curve ◽  
Light Water Reactor ◽  
Design Curve ◽  
Fatigue Design ◽  
American Society ◽  
Design Factors

Technical support is provided for a fatigue curve that could potentially be incorporated into Section III of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code. This fatigue curve conservatively accounts for the effects of light water reactor environments on the fatigue behavior of austenitic stainless steels. This paper presents the data, statistical methods, and basis for the design factors appropriate for Code applications. A discussion of the assumptions and methods used in design curve development is presented.

Study on Incorporation of New Design Fatigue Curves and a New Environmental Fatigue Correction Factor for PWR Environment Into the JSME Environmental Fatigue Evaluation Method

2020 ◽  
Author(s):  
Seiji Asada ◽  
Shengde Zhang ◽  
Masahiro Takanashi ◽  
Yuichiro Nomura
Keyword(s):  
Stainless Steel ◽  
Base Metal ◽  
Stainless Steels ◽  
Evaluation Method ◽  
Austenitic Stainless Steels ◽  
Steel Base ◽  
Improved Design ◽  
Fatigue Evaluation ◽  
Cast Stainless Steel ◽  
Metal Weld

Abstract Improved design fatigue curves were developed in the Subcommittee on Design Fatigue Curve in the Atomic Energy Research Committee in the Japan Welding Engineering Society (JWES). Working Group on Design Fatigue Curves (WG DFC) in the JSME has studied the validity and the applicability of the improved design fatigue curves developed in the JWES to incorporate into the JSME Environmental Fatigue Evaluation Method. The authors propose a fatigue analysis method using the design fatigue curves developed in the JWES that are applied revised factors to optimize the environmental fatigue analysis. Also, the Japanese pressurized water reactor (PWR) utility group developed equations of environmental fatigue factors (Fen) for austenitic stainless steel base metal, weld metal and cast stainless steel in PWR environment. The WG DFC has investigated the Fen equations and concluded that the Fen equation of austenitic stainless steel base metal is the most conservative among the three equations and close to NUREG/CR-6909 Rev.1 [24]. The authors propose to use the Fen equation for base metal for austenitic stainless steels for all of the base metal, weld metal and cast stainless steel. In addition, the authors have confirmed that the employment of the proposed Fen equation to the proposed design fatigue curves of austenitic stainless steels accurately predicts the existing environmental fatigue test data of austenitic stainless steels, which were used in the development of the current Fen equation of austenitic stainless steels in PWR environments in the JSME Environmental Fatigue Evaluation Method. Therefore, the proposed Fen equation can be applied to environmental fatigue evaluation for austenitic stainless steels.

Research of Design Evaluation Method Based on the Jack Human Model

2013 ◽  
Vol 365-366 ◽  
pp. 117-120
Author(s):  
Ying Li ◽  
Deng Kai Chen ◽  
Sui Huai Yu ◽  
Zheng Li
Keyword(s):  
Detailed Analysis ◽  
Evaluation Method ◽  
Machine Design ◽  
Human Model ◽  
Design Evaluation ◽  
Computer Design ◽  
Emergency Communication ◽  
Vehicle Cabin ◽  
Emergency Communications ◽  
Design Factors

This paper focused on the area of simulation of man-machine applications, using JACK ergonomic software, and have a detailed analysis of sight of domain, and comfort of human-computer design factors to achieve a auxiliary design. The paper combines the emergency communications vehicles emergency communication vehicle cabin man-machine design examples to verify the effectiveness of the proposed method.

Proposed ASME Code High Cycle Fatigue Design Curves for Austenitic and Ferritic Steels

2017 ◽  
Author(s):  
Sampath Ranganath ◽  
Hardayal S. Mehta ◽  
Nathan A. Palm ◽  
John Hosler
Keyword(s):  
High Cycle Fatigue ◽  
Ferritic Steels ◽  
Mean Stress ◽  
Cycle Fatigue ◽  
Design Curve ◽  
Fatigue Design ◽  
Asme Code ◽  
The Mean ◽  
Number Of Cycles ◽  
Fatigue Evaluation

The ASME Code fatigue curves (S–N curves) are used in the fatigue evaluation of reactor components. For the assessment of high frequency cyclic loading (such as those produced by flow-induced vibrations), where the number of cycles is expected to be very large and cannot be estimated, the stresses are evaluated by comparison with the fatigue limit1 at 1011 cycles. Other high cycle events of finite time duration (e.g. safety relief loading), where the number of cycles is large but well defined, the fatigue evaluation is performed by comparing the calculated stress with the allowable values defined by the high cycle fatigue design curve. This paper discusses the development of fatigue design curves for austenitic and ferritic steels when the number of cycles is in the range 106 – 1011 cycles. The first part of the paper addresses austenitic stainless steel components which are used for reactor internals. Specifically, the approach described here uses temperature dependent properties (cyclic yield strength, cyclic ultimate strength) for the mean stress correction and the correction for the modulus of elasticity. The high cycle fatigue design curve is developed by applying the mean stress and the E correction on the reversing load mean data curve and applying a factor of 2 on stress. The generic methodology developed for austenitic steel was applied to carbon and low alloy steels also. The proposed fatigue design curves are part of a draft ASME Code Case being considered by the ASME Code Subgroup on Design Methods. This paper describes the technical basis for the proposed ASME Code Case for the high cycle fatigue design curves for austenitic and ferritic steels.

Fatigue Benchmark Comparison Effort Between Code_Aster and CNNC/NPIC Software: Part 2

2020 ◽  
Author(s):  
Hai Xie ◽  
Zichen Kong ◽  
Xuejiao Shao ◽  
Tanguy Mathieu ◽  
Furui Xiong
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Austenitic Stainless Steels ◽  
Combination Method ◽  
Practical Implementation ◽  
Phase 2 ◽  
Software Comparison ◽  
Fatigue Design ◽  
Nickel Base ◽  
Fatigue Evaluation

Abstract Fatigue is identified as a significant degradation mode that affects nuclear power plants world-wide. Recent research on the interaction between fatigue degradation and the influence of PWR environment has caused international concern and triggered numerous research programs [1]. In this context, several codes & standards, including the RCC-M code, have included some technical mandatory or non-mandatory sections to address the issue. In RCC-M, this is compiled in the Rules in Probation Phase 2 and 3 [2]. Due to the novelty of these rules, there is room for improvement for the specific and practical implementation of these rules. AFCEN has hence launched a benchmark exercise at the end of 2019 to help increase the quality of these rules. Part 1 of this paper [3] states that EDF and CNNC/NPIC have launched an effort to benchmark their respective codes on fatigue calculation including the EAF algorithm. In the second part of the benchmark, the two companies started the code comparison based on a benchmark case provided by AFCEN. As stated previously, the 2016 edition of RCC-M code integrates the modifications made to the Code in Probation Phase 2 and 3(RPP)[2], which respectively modify the fatigue design curve for austenitic stainless steels and Nickel base alloys, as well as integrate environmental effects in the fatigue evaluation for austenitic stainless steel components. In this paper, a comparison between RCC-M RPP and NUREG/CR-6909 rev.1 [3] is proposed. The comparison focuses on the technical details of the strain rate calculation and transient combination method. The cumulative fatigue usage factor with or without considering EAF according to RCC-M RPP – 2 and RPP – 3 is given by EDF, using code_aster and its POST_RCCM operator. CNNC/NPIC will provide multiple sets of results including cumulative fatigue usage factors according to RCC-M RPP and NUREG CR/6909 rev. 1 respectively using its own software. Comparison of selection for peak and valleys points, Sn and Fen values are also presented. Differences of the algorithms of the two codes are also discussed.

Optimization of Environmental Fatigue Evaluation: Step 2

2009 ◽  
Author(s):  
Yuichirou Nomura ◽  
Kazuya Tsutsumi ◽  
Toshihide Inoue ◽  
Seiji Asada ◽  
Takao Nakamura
Keyword(s):  
Evaluation Method ◽  
Fatigue Curve ◽  
Pressure Vessels ◽  
Austenitic Steels ◽  
Transient Conditions ◽  
Future Studies ◽  
Data Scatter ◽  
Fatigue Evaluation ◽  
Design Factors ◽  
Typical Design

In order to introduce environmental effects into fatigue evaluation of design and construction codes, the environmental fatigue evaluation method should not only be established, but the conservativeness of the codes, design transient conditions and so on should also be reviewed. The former paper [1] presented in 2007 ASME Pressure Vessels and Piping Conference reviewed and discussed design factors of design fatigue curves, design transient conditions, stress analysis techniques and environmental fatigue evaluation methods. In this paper, rationalization of typical design transient conditions is discussed and design factors of a design fatigue curve for austenitic steels are studied. Rationalized numbers and/or conditions are proposed for the typical design transients that are dominant for fatigue evaluation. A mean fatigue curve of austenitic steels is analyzed by using a statistical method with the latest data. The design factors of the fatigue curve of austenitic steels are investigated for parameters decreasing fatigue life such as size effect, surface finish and data scatter and appropriate design factors are proposed. Future studies are discussed.

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