Fatigue and Creep-Fatigue Testing of Bellows at Elevated Temperature

1988 ◽  
Vol 110 (3) ◽  
pp. 301-307 ◽  
Author(s):  
S. Yamamoto ◽  
K. Isobe ◽  
S. Ohte ◽  
N. Tanaka ◽  
S. Ozaki ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Life Prediction ◽  
Room Temperature ◽  
Fatigue Testing ◽  
Prediction Method ◽  
Fatigue Tests ◽  
Finite Element Analyses ◽  
Strain Behavior ◽  
Creep Fatigue ◽  
Inner Diameter

Fatigue and creep-fatigue tests at elevated temperature were conducted on two different-sized bellows, φ 1100 mm and φ 300 mm in nominal inner diameter, to investigate the fatigue life and the creep-fatigue interaction in a bellows, and also to provide test data for developing a life prediction method and design-by-analysis rules for bellows in elevated temperature service. A series of tests consisted of strain behavior and fatigue tests at room temperature, and fatigue and creep-fatigue tests at elevated temperature. Also, inelastic finite element analyses were performed on a bellows under internal pressure and cyclic axial deflections. Analytical results were compared with the measured data obtained in the room temperature testing to verify the strain prediction method.

Study on Life Prediction Method for Creep-Fatigue Interaction at Elevated Temperature

2007 ◽  
Vol 353-358 ◽  
pp. 190-194
Author(s):  
Nian Jin Chen ◽  
Zeng Liang Gao ◽  
Wei Zhang ◽  
Yue Bao Le
Keyword(s):  
Elevated Temperature ◽  
Prediction Model ◽  
Life Prediction ◽  
Low Cycle Fatigue ◽  
Hold Time ◽  
Prediction Method ◽  
Fatigue Tests ◽  
Cycle Fatigue ◽  
Creep Fatigue ◽  
316L Austenitic Stainless Steel

The law of low-cycle fatigue with hold time at elevated temperature is investigated in this paper. A new life prediction model for the situation of fatigue and creep interaction is developed, based on the damage due to fatigue and creep. In order to verify the prediction model, strain-controlled low-cycle fatigue tests at temperature 693K, 823K and 873K and fatigue tests with various hold time at temperature 823K and 873K for 316L austenitic stainless steel were carried out. Good agreement is found between the predictions and experimental results.

Life Prediction of Two Rotor Steels under Creep-Fatigue Interaction at Elevated Temperature

2013 ◽  
Vol 470 ◽  
pp. 581-584 ◽  
Author(s):  
Hong Xu ◽  
Wei Wei Zhang ◽  
Karl Maile
Keyword(s):  
Fatigue Life ◽  
Elevated Temperature ◽  
Life Prediction ◽  
Hold Time ◽  
Fatigue Tests ◽  
Prediction Methods ◽  
Life Data ◽  
Creep Fatigue ◽  
Life Predictions ◽  
Interaction Behaviors

The fatigue tests with 16 hours hold time have been conducted for two rotor steels, 1CrMoV and 2CrMoNiVW at 550°C to investigate their creep-fatigue interaction behaviors, as well as those without hold time for contrast. And two life prediction methods are used to correlate the present creep-fatigue life data. It is shown that a significant reduction in fatigue life is observed with hold time in tension, and it is also observed that 1CrMoV steel exhibits a higher creep-fatigue life than 2CrMoNiVW when strain hold time is 16 hours, and 2CrMoNiVW seems to be more sensitive to hold time influence. In addition, both methods could give satisfactory creep-fatigue life predictions, but with their own limitations.

scholarly journals Experimental Design and Validation of an Accelerated Random Vibration Fatigue Testing Methodology

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Yu Jiang ◽  
Gun Jin Yun ◽  
Li Zhao ◽  
Junyong Tao
Keyword(s):  
Fatigue Life ◽  
Stress Responses ◽  
Life Prediction ◽  
Random Vibration ◽  
Fatigue Testing ◽  
Fatigue Tests ◽  
Fatigue Life Prediction ◽  
Power Spectral ◽  
Vibration Fatigue ◽  
Non Gaussian

Novel accelerated random vibration fatigue test methodology and strategy are proposed, which can generate a design of the experimental test plan significantly reducing the test time and the sample size. Based on theoretical analysis and fatigue damage model, several groups of random vibration fatigue tests were designed and conducted with the aim of investigating effects of both Gaussian and non-Gaussian random excitation on the vibration fatigue. First, stress responses at a weak point of a notched specimen structure were measured under different base random excitations. According to the measured stress responses, the structural fatigue lives corresponding to the different vibrational excitations were predicted by using the WAFO simulation technique. Second, a couple of destructive vibration fatigue tests were carried out to validate the accuracy of the WAFO fatigue life prediction method. After applying the proposed experimental and numerical simulation methods, various factors that affect the vibration fatigue life of structures were systematically studied, including root mean squares of acceleration, power spectral density, power spectral bandwidth, and kurtosis. The feasibility of WAFO for non-Gaussian vibration fatigue life prediction and the use of non-Gaussian vibration excitation for accelerated fatigue testing were experimentally verified.

scholarly journals Life Prediction Method Under Creep-Fatigue Loading for Gas Turbine Combustion Transition Piece of Ni-Based Superalloy N263

1997 ◽  
Author(s):  
J. Kusumoto ◽  
H. Watanabe ◽  
A. Kanaya ◽  
K. Ichikawa ◽  
S. Sakurai
Keyword(s):  
Crack Length ◽  
Surface Crack ◽  
Life Prediction ◽  
Prediction Method ◽  
Fatigue Loading ◽  
Maximum Surface ◽  
Creep Fatigue ◽  
Loading Tests ◽  
Transition Piece ◽  
Life Fraction

In order to develop the life prediction method under creep-fatigue loading for gas turbine combustion transition piece, creep-fatigue tests were carried out on both as-received and aged Ni-based superalloy Nimonic 263. Crack initiation and propagation behaviors for the smooth specimen were observed. An unique relationship was obtained between life fraction and the maximum surface crack length under triangular wave shape loading tests, except the results for the trapezoidal wave loading tests. The latter results were due to the over estimation of the surface crack length at the crack initiation. These were caused from an oxide film break during straining. In the case of removing the oxide film before the measurement of surface crack, the relationship between life fraction and the maximum surface crack length obtained as unique relationship regardless of triangular and trapezoidal strain wave shapes. Using the life prediction method proposed, which is based on maximum surface crack length, the damage of combustion transition piece materials in service was evaluated.

Life Prediction of Stainless Steels under Creep-Fatigue

2009 ◽  
Vol 413-414 ◽  
pp. 725-732 ◽  
Author(s):  
Xiao Cong He
Keyword(s):  
Stainless Steel ◽  
Elevated Temperature ◽  
Test Data ◽  
Stainless Steels ◽  
Life Prediction ◽  
Prediction Models ◽  
Fatigue Behavior ◽  
Summation Method ◽  
Tensile Creep ◽  
Creep Fatigue

The aim of this study is to investigate the creep-fatigue behavior of stainless steel materials. Based on the elevated-temperature tensile, creep and rupture test data, thermal creep-fatigue modelling was conducted to predict the failure life of stainless steels. In the low cycle thermal fatigue life model, Manson’s Universal Slopes equation was used as an empirical correlation which relates fatigue endurance to tensile properties. Fatigue test data were used in conjunction with different modes to establish the relationship between temperature and other parameters. Then creep models were created for stainless steel materials. In order to correlate the results of short-time elevated temperature tests with long-term service performance at more moderate temperatures, different creep prediction models, namely Basquin model, Sherby-Dorn model and Manson-Haferd model, were studied. Comparison between the different creep prediction models were carried out for a range of stresses and temperatures. A linear damage summation method was used to establish life prediction model of stainless steel materials under creep-fatigue.

On a Design Acceptability of 90° Elbow According to Pipe Length at Elevated Temperature Condition

2016 ◽  
Author(s):  
Seong-Yun Jeong ◽  
Min-Gu Won ◽  
Jae-Boong Choi ◽  
Nam-Su Huh ◽  
Young-Jin Oh
Keyword(s):  
Elevated Temperature ◽  
Structural Integrity ◽  
Seismic Damage ◽  
Design Codes ◽  
Finite Element Analyses ◽  
Promising Candidate ◽  
Pipe Length ◽  
Integrity Assessment ◽  
Creep Fatigue ◽  
Elevated Temperature Design

Sodium-cooled Fast Reactor, SFR is promising candidate of Generation-IV reactor. SFR is operated at high temperature and low pressure. For reducing high thermal stress, thin-walled components and structures are employed for SFR. However, thins-walled components are vulnerable to seismic damage[1]. In this paper, the structural integrity assessment are performed to investigate the effect of piping length on creep-fatigue and seismic damage at elevated temperature. L-shaped elbow is considered for piping design and finite element analyses are conducted to calculate creep-fatigue and seismic damage. The evaluation of creep fatigue damage is carried out according to the elevated temperature design codes of ASME B&PV Sec. III Subsec. NH-3200[2]. Seismic damage are evaluated based ASME B&PV Sec. III Subsec. NB-3600[3] and ASME B&PV Sec. III Div.5 HBB-3200[4]. From the results of creep-fatigue and seismic damage, limit length of piping is determined.

scholarly journals Application of a √ area -Approach for Fatigue Assessment of Cast Aluminum Alloys at Elevated Temperature

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1033 ◽  
Author(s):  
Roman Aigner ◽  
Christian Garb ◽  
Martin Leitner ◽  
Michael Stoschka ◽  
Florian Grün
Keyword(s):  
Elevated Temperature ◽  
Fatigue Strength ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Damage Mechanism ◽  
Cyclic Fatigue ◽  
Fatigue Tests ◽  
Cast Aluminum ◽  
Fatigue Assessment ◽  
Cast Aluminum Alloys

This paper contributes to the effect of elevated temperature on the fatigue strength of common aluminum cast alloys EN AC-46200 and EN AC-45500. The examination covers both static as well as cyclic fatigue investigations to study the damage mechanism of the as-cast and post-heat-treated alloys. The investigated fracture surfaces suggest a change in crack origin at elevated temperature of 150 ∘ C. At room temperature, most fatigue tests reveal shrinkage-based micro pores as their crack initiation, whereas large slipping areas occur at elevated temperature. Finally, a modified a r e a -based fatigue strength model for elevated temperatures is proposed. The original a r e a model was developed by Murakami and uses the square root of the projected area of fatigue fracture-initiating defects to correlate with the fatigue strength at room temperature. The adopted concept reveals a proper fit for the fatigue assessment of cast Al-Si materials at elevated temperatures; in detail, the slope of the original model according to Murakami should be decreased at higher temperatures as the spatial extent of casting imperfections becomes less dominant at elevated temperatures. This goes along with the increased long crack threshold at higher operating temperature conditions.

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