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

2007 ◽  
pp. 190-194
Author(s):  
Nian Jin Chen ◽  
Zeng Liang Gao ◽  
Wei Zhang ◽  
Yue Bao Le
Keyword(s):  
Elevated Temperature ◽  
Life Prediction ◽  
Prediction Method ◽  
Creep Fatigue

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.

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.

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.

Study on Simplified Prediction Method of Thermal Ratchet Deformation Based on Parallel Bar Model

2014 ◽  
Author(s):  
Toshiaki Kokufuda ◽  
Naoto Kasahara
Keyword(s):  
Elevated Temperature ◽  
Inelastic Deformation ◽  
Evaluation Method ◽  
Failure Modes ◽  
Prediction Method ◽  
Inelastic Strain ◽  
Primary Stress ◽  
Redistribution Mechanism ◽  
Creep Fatigue ◽  
Calculation Results

For elevated temperature structures such as fast breeder reactor components, inelastic deformation is likely to occur because of reduction of yield stress and occurrence of creep deformation. The typical failure modes for elevated temperature structures are excessive deformation caused by the accumulation of inelastic deformation and creep fatigue caused by inelastic strain concentration at structure discontinuities. In order to prevent such failures, it is necessary to evaluate inelastic deformation adequately. Thermal ratchet deformation, namely the progressive plastic deformation induced by cyclic thermal stress with uniform primary stress, has some possibility resulting in excessive deformation. ASME boiler & pressure vessel code provides elastic evaluation methods for thermal ratchet. However, these methods are so focused on preventing thermal ratchet deformation, that it could be too conservative under some conditions. Therefore, a simplified elastic evaluation method to quantify thermal ratchet deformation is desired. In this paper, the simplified prediction method for thermal ratchet deformation is proposed using parallel bar model, which represents stress redistribution mechanism of cylindrical vessels. The solution of thermal ratchet deformation of parallel bar model was derived and compared with FEM calculation results of cylindrical vessels. This theoretical solution is proposed as a prediction method for thermal ratchet deformation of cylindrical vessels. The applicable area of the proposed prediction method is the cylindrical vessel under linear and parabolic temperature distribution through the wall thickness.

Thermomechanical fatigue life prediction method for nickel-based superalloy in aeroengine turbine discs under multiaxial loading

2019 ◽  
Vol 28 (9) ◽  
pp. 1344-1366 ◽  
Author(s):  
Fang-Dai Li ◽  
De-Guang Shang ◽  
Cheng-Cheng Zhang ◽  
Xiao-Dong Liu ◽  
Dao-Hang Li ◽  
...  
Keyword(s):  
Fatigue Damage ◽  
Cyclic Deformation ◽  
Deformation Behavior ◽  
Life Prediction ◽  
Prediction Method ◽  
Creep Damage ◽  
Damage Mechanism ◽  
Thermomechanical Fatigue ◽  
Nickel Based Superalloy ◽  
Creep Fatigue

The multiaxial thermomechanical fatigue properties for nickel-based superalloy GH4169 in aeroengine turbine discs are investigated in this paper. Four types of axial–torsional thermomechanical fatigue experiments were performed to identify the cyclic deformation behavior and the damage mechanism. The experimental results showed that the creep damage can be generated under thermally in-phase loading while it can be ignored under thermally out-of-phase loading, and the responded stress increasing phenomenon, that is, non-proportional hardening, can be shown under the mechanically out-of-phase strain loading. Based on the analysis of cyclic deformation behavior and damage mechanism, a life prediction method was proposed for multiaxial thermomechanical fatigue, in which the pure fatigue damage, the creep damage, and the interaction between them were simultaneously considered. The pure fatigue damage can be calculated by the isothermal fatigue parameters corresponding to the temperature without creep; the creep damage can be calculated by the principle of subdivision, and the creep–fatigue interaction can be determined by creep damage, fatigue damage, and an interaction coefficient which is used to reflect the creep–fatigue interaction strength. The predicted results showed that the proposed method is reasonable.

Application of a Non-Interactive Constitutive Model for Life Prediction of 2.25Cr-1Mo Under Creep-Fatigue

2017 ◽  
Author(s):  
Ali P. Gordon ◽  
Firat Irmak ◽  
Thomas Bouchenot ◽  
Bassem Felemban
Keyword(s):  
Elevated Temperature ◽  
Constitutive Model ◽  
Life Prediction ◽  
Low Cycle Fatigue ◽  
Low Alloy Steels ◽  
Creep Fatigue ◽  
Damage Maps ◽  
Alloy Steels ◽  
Failure Life ◽  
Prediction Approach

Despite the significant progress in the development of modern alloys, low alloy steels continue to be the materials of choice for large structural components at elevated temperature for extended periods of time. The resistance of these alloys to deformation and damage under creep and/or fatigue at elevated temperature make them suitable for components expected to endure decades of service. The material 2.25Cr-1Mo is commonly applied in boilers, heat exchanger tubes, and throttle valve bodies in both turbomachinery and pressure-vessel/piping applications alike. It has an excellent balance of ductility, corrosion resistance, and creep strength under moderate temperatures (i.e., up to 650°C). In the present work, a life prediction approach is developed for situations where the material is subjected conditions where creep and fatigue are prevalent. Parameters for the approach are based on regression fits in comparison with a broad collection experimental data. The data are comprised of low cycle fatigue (LCF) and creep fatigue (CF) experiments. The form of the life prediction model follows the cumulative damage approach where dominant damage maps can be used to identify primary microstructural mechanism associated with failure. Life calculations are facilitated by the usage of a non-interacting creep-plasticity constitutive model capable of representing not only the temperature- and rate-dependence, but also the history-dependence of the material. For the inelastic response, both the Garofalo and Chaboche models for creep and plasticity are employed, respectively.

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