THE FATIGUE EVALUATION METHOD FOR A STRUCTURAL STAINLESS STEEL USING THE MAGNETIC SENSOR COMPOSED OF THREE PANCAKE COILS

2011 ◽  
Author(s):  
M. Oka ◽  
Y. Tsuchida ◽  
T. Yakushiji ◽  
M. Enokizono ◽  
Donald O. Thompson ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Evaluation Method ◽  
Magnetic Sensor ◽  
Pancake Coils ◽  
Fatigue Evaluation

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.

Development of New Design Fatigue Curves in Japan: Discussion of Effect of Surface Finish on Fatigue Strength of Nuclear Component Materials

2019 ◽  
Author(s):  
Motoki Nakane ◽  
Yun Wang ◽  
Hisamitsu Hatoh ◽  
Masato Yamamoto ◽  
Akihiko Hirano ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Fatigue Strength ◽  
Carbon Steel ◽  
Fatigue Test ◽  
Surface Finish ◽  
Evaluation Method ◽  
Maximum Height ◽  
Test Results ◽  
Nuclear Component ◽  
Fatigue Evaluation

Abstract Based on the world wide fatigue test database, The Design Fatigue Curve (DFC) Phase 1 and 2 subcommittees established in The Japan Welding Engineering Society (JWES) have been developed new design fatigue curves which are applied for the nuclear component materials, in air environment. The effects of the design factor, such as mean stress, size effect and surface finish, etc. on the fatigue curves are also discussed with the fatigue database in order to construct fatigue evaluation method for the new design fatigue curves. The subcommittees also have studied the applicability of newly developed fatigue evaluation method to the nuclear component materials. This paper reports the fatigue test results of machined finished small-scale test specimens which are used for the verification of proposed fatigue evaluation method. The materials subjected to the fatigue tests are austenitic stainless steel SUS316LTP, low-alloy steels SQV2A and SCM435H, and carbon steel STPT370. Specimens finished with lathe machining are subjected to the tests. The planed maximum height roughness of the specimen are 25 and 100 μm. The fatigue test results show that the surface finish effect on the fatigue strength in the high cycle region of the austenitic stainless steel can be negligible. On the other hand, fatigue strength of the carbon steel and low alloy steel is decreased as increasing the surface roughness of the specimen. Especially, decrease of fatigue strength for the specimens with more than 100 μm maximum height roughness is larger than that of conventional estimation. It is presumed that severe roughness introduced by lathe machining tends to behave as notches and increase the stress concentration at the specimen surface, and resulted in unexpected decrease of fatigue strength.

Development of Creep–Fatigue Evaluation Method for 316FR Stainless Steel

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Yuji Nagae ◽  
Shigeru Takaya ◽  
Tai Asayama
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
Evaluation Method ◽  
Elevated Temperatures ◽  
Strain Curve ◽  
Creep Damage ◽  
Fatigue Curve ◽  
Time To Failure ◽  
Creep Fatigue ◽  
Fatigue Evaluation

In the design of fast reactor plants, the most important failure mode to be prevented is creep–fatigue damage at elevated temperatures. 316FR stainless steel is a candidate material for the reactor vessel and internal structures of such plants. The development of a procedure for evaluating creep–fatigue life is essential. The method for evaluating creep–fatigue life implemented in the Japan Society of Mechanical Engineers code is based on the time fraction rule for evaluating creep damage. Equations such as the fatigue curve, dynamic stress–strain curve, creep rupture curve, and creep strain curve are necessary for calculating creep–fatigue life. These equations are provided in this paper and the predicted creep–fatigue life for 316FR stainless steel is compared with experimental data. For the evaluation of creep–fatigue life, the longest time to failure is about 100,000 h. The creep–fatigue life is predicted to an accuracy that is within a factor of 2 even in the case with the longest time to failure. Furthermore, the proposed method is compared with the ductility exhaustion method to investigate whether the proposed method gives conservative predictions. Finally, a procedure based on the time fraction rule for the evaluation of creep–fatigue life is proposed for 316FR stainless steel.

scholarly journals Research on Strength Test Technology and Fatigue Evaluation Method of Bogie Frame and Body Bolster

2021 ◽  
Vol 1972 (1) ◽  
pp. 012038
Author(s):  
Cao Yu ◽  
Lu Chong ◽  
Li Zihua ◽  
Song Jie ◽  
Ding Xiebin
Keyword(s):  
Evaluation Method ◽  
Strength Test ◽  
Bogie Frame ◽  
Test Technology ◽  
Fatigue Evaluation

Development of 2012 Edition of JSME Code for Design and Construction of Fast Reactors: (4) Creep–Fatigue Evaluation Method for Modified 9Cr–1Mo Steel

2013 ◽  
Author(s):  
Shigeru Takaya ◽  
Yuji Nagae ◽  
Tai Asayama
Keyword(s):  
Evaluation Method ◽  
Time To Failure ◽  
Test Results ◽  
Fast Reactors ◽  
Material Test ◽  
Creep Fatigue ◽  
Summation Rule ◽  
Fatigue Evaluation ◽  
Failure Life ◽  
Design And Construction

This paper describes a creep–fatigue evaluation method for modified 9Cr–1Mo steel, which has been newly included in the 2012 edition of the JSME code for design and construction of fast reactors. In this method, creep and fatigue damages are evaluated on the basis of Miner’s rule and the time fraction rule, respectively, and the linear summation rule is employed as the failure criterion. Investigations using material test results are conducted, which show that the time fraction approach can conservatively predict failure life if margins on the initial stress of relaxation and the stress relaxation rate are embedded. In addition, the conservatism of prediction tends to increase with time to failure. Comparison with the modified ductility exhaustion method, which is known to have good failure life predictability in material test results, shows that the time fraction approach predicts failure lives to be shorter in long-term strain hold conditions, where material test data is hardly obtained. These results confirm that the creep–fatigue evaluation method in the code has implicit conservatism.

scholarly journals Muscle fatigue evaluation method of driver at long time driving based on blood lactate level increase

2020 ◽  
Vol 86 (889) ◽  
pp. 19-00433-19-00433
Author(s):  
Takumi YAMAKAWA ◽  
Soichiro HAYAKAWA ◽  
Katsuhiro ASANO ◽  
Shigeyoshi TSUTSUMI ◽  
Ryojun IKEURA
Keyword(s):  
Muscle Fatigue ◽  
Blood Lactate ◽  
Lactate Level ◽  
Evaluation Method ◽  
Blood Lactate Level ◽  
Level Increase ◽  
Long Time ◽  
Fatigue Evaluation
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