Multiaxial Low Cycle Fatigue Life Prediction at 300 °C Using Equivalent Strain Appoach

2011 ◽  
Vol 361-363 ◽  
pp. 1669-1672
Author(s):  
Wen Xiao Zhang ◽  
Guo Dong Gao ◽  
Guang Yu Mu
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Strain Range ◽  
Cyclic Fatigue ◽  
Equivalent Strain ◽  
Multiaxial Fatigue ◽  
Fatigue Life Prediction ◽  
Cycle Fatigue

The low cycle fatigue behavior was experimentally studied with the 3-dimension notched LD8 aluminum alloy specimens at 300°C. The 3- dimension stress-strain responses of specimens were calculated by means of the program ADINA. The multiaxial fatigue life prediction was carried out according to von Mises’s equivalent theory. The results from the prediction showed that the equivalent strain range can be served as the valid mechanics for predicting multiaxial high temperature and low cyclic fatigue life.

Fatigue Life Prediction Using Average Strain Range of Fatigue Process Zone

2010 ◽  
Vol 29-32 ◽  
pp. 474-478
Author(s):  
Dong Lei ◽  
Bin Kai Shi ◽  
Ge Li ◽  
Jian Hua Zhao
Keyword(s):  
Fatigue Life ◽  
Stress Concentration ◽  
Life Prediction ◽  
Low Cycle Fatigue ◽  
Process Zone ◽  
Strain Range ◽  
Fatigue Life Prediction ◽  
Cycle Fatigue ◽  
Average Strain ◽  
Fatigue Process

In low-cycle fatigue process, plastic strain takes place at notch root vicinity fast appears induced by high stress concentration. Plastic strain makes material non-uniform and the change of distribution of local stress. The approximation to stress concentration point of Neuber’s rule is not suitable for some plastic materials in engineering practice. In this paper, the average strain of fatigue process zone was considered to substitute Neuber strain for predicting fatigue life. Prediction results indicated that average strain range of fatigue process zone is more suitable than Neuber strain range for predicting low-cycle fatigue life of LY12CZ.

scholarly journals A novel model for low-cycle multiaxial fatigue life prediction based on the critical plane-damage parameter

2020 ◽  
Vol 103 (3) ◽  
pp. 003685042093622
Author(s):  
Jianhui Liu ◽  
Xin Lv ◽  
Yaobing Wei ◽  
Xuemei Pan ◽  
Yifan Jin ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Failure Mechanism ◽  
Fatigue Failure ◽  
Prediction Accuracy ◽  
Life Prediction ◽  
Low Cycle Fatigue ◽  
Multiaxial Fatigue ◽  
Fatigue Life Prediction ◽  
Cycle Fatigue ◽  
Classic Model

Multiaxial fatigue of the components is a very complex behavior. This analyzes the multiaxial fatigue failure mechanism, reviews and compares the advantages and disadvantages of the classic model. The fatigue failure mechanism and fatigue life under multiaxial loading are derived through theoretical analysis and formulas, and finally verified with the results of multiaxial fatigue tests. The model of multiaxial fatigue life for low-cycle fatigue life prediction model not only improves the prediction accuracy of the classic model, but also considers the effects of non-proportional additional hardening phenomena and fatigue failure modes. The model is proved to be effective in low-cycle fatigue life prediction under different loading paths and types for different materials. Compared with the other three classical models, the proposed model has higher life prediction accuracy and good engineering applicability.

Probabilistic Model of the Multiaxial Low-Cycle Fatigue Life Prediction

2012 ◽  
Vol 479-481 ◽  
pp. 2135-2140
Author(s):  
Lei Wang ◽  
Tian Zhong Sui ◽  
Hang Zhao ◽  
En Guo Men
Keyword(s):  
Fatigue Life ◽  
Carbon Steel ◽  
Probabilistic Model ◽  
Life Prediction ◽  
Low Cycle Fatigue ◽  
Medium Carbon Steel ◽  
Multiaxial Fatigue ◽  
Fatigue Life Prediction ◽  
Cycle Fatigue ◽  
Medium Carbon

First, several widely used models of the multiaxial low-cycle fatigue life prediction based on the critical plane approach were presented in this paper, and the predicted results of these models for a medium carbon steel under the condition of multiaxial low-cycle fatigue loading were compared. Second, the stochastic expressions and probability density function curves of the fatigue performance parameters were obtained by probabilistic analysis of the medium carbon steel fatigue data. Finally, the probabilistic model of the multiaxial fatigue life prediction was simulated by Monte Carlo Method, which should provide a basis for the reliability analysis of engineering components subjected to the multiaxial complex loads.

Influence of Hold-Time and Temperature on the Low-Cycle Fatigue of Incoloy 800

1972 ◽  
Vol 94 (3) ◽  
pp. 930-934 ◽  
Author(s):  
C. E. Jaske ◽  
H. Mindlin ◽  
J. S. Perrin
Keyword(s):  
Fatigue Life ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Compressive Strain ◽  
Hold Time ◽  
Strain Range ◽  
Cyclic Fatigue ◽  
Cycle Fatigue ◽  
Incoloy 800 ◽  
Strain Cycling

A study has been conducted to determine the low-cycle fatigue behavior of solution-annealed Incoloy 800 bar at temperatures from 800–1400 deg F. The experimental work included evaluation of specimens under both continuous, completely reversed strain cycling and under strain cycling with hold time periods at the strain limits. At 1000, 1200, and 1400 deg F, it was found that 10-min hold-times at the tensile strain limit during every cycle significantly reduced the cyclic fatigue life compared to continuous cycling. However, there was little reduction in cyclic fatigue life when 10-min hold-times were introduced at the compressive strain limits or at both the tensile and compressive limits. The ratio of hold-time cyclic fatigue life to no-hold-time cyclic fatigue life decreased as the length of hold time increased (at constant total strain range) and as the magnitude of strain range decreased (at constant hold-time length).

A weight function method for multiaxial low-cycle fatigue life prediction under variable amplitude loading

2018 ◽  
Vol 53 (4) ◽  
pp. 197-209 ◽  
Author(s):  
Xiao-Wei Wang ◽  
De-Guang Shang ◽  
Yu-Juan Sun
Keyword(s):  
Fatigue Life ◽  
Weight Function ◽  
Life Prediction ◽  
Function Method ◽  
Low Cycle Fatigue ◽  
Fatigue Life Prediction ◽  
Cycle Fatigue ◽  
Critical Plane ◽  
Variable Amplitude ◽  
Weight Function Method

A weight function method based on strain parameters is proposed to determine the critical plane in low-cycle fatigue region under both constant and variable amplitude tension–torsion loadings. The critical plane is defined by the weighted mean maximum absolute shear strain plane. Combined with the critical plane determined by the proposed method, strain-based fatigue life prediction models and Wang-Brown’s multiaxial cycle counting method are employed to predict the fatigue life. The experimental critical plane orientation and fatigue life data under constant and variable amplitude tension–torsion loadings are used to verify the proposed method. The results show that the proposed method is appropriate to determine the critical plane under both constant and variable amplitude loadings.

LOW CYCLE FATIGUE BEHAVIOR AND LIFE PREDICTION OF A CAST COBALT-BASED SUPERALLOY

2012 ◽  
Vol 06 ◽  
pp. 251-256
Author(s):  
HO-YOUNG YANG ◽  
JAE-HOON KIM ◽  
KEUN-BONG YOO
Keyword(s):  
Fatigue Life ◽  
Strain Energy ◽  
Life Prediction ◽  
Prediction Models ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Total Strain ◽  
Cycle Fatigue ◽  
Total Strain Range ◽  
Different Temperatures

Co -base superalloys have been applied in the stationary components of gas turbine owing to their excellent high temperature properties. Low cycle fatigue data on ECY-768 reported in a companion paper were used to evaluate fatigue life prediction models. In this study, low cycle fatigue tests are performed as the variables of total strain range and temperatures. The relations between plastic and total strain energy densities and number of cycles to failure are examined in order to predict the low cycle fatigue life of Cobalt-based super alloy at different temperatures. The fatigue lives is evaluated using predicted by Coffin-Manson method and strain energy methods is compared with the measured fatigue lives at different temperatures. The microstructure observing was performed for how affect able to low-cycle fatigue life by increasing the temperature.

scholarly journals Multiaxial fatigue life estimation in low-cycle fatigue regime including the mean stress effect

2018 ◽  
Vol 165 ◽  
pp. 16002
Author(s):  
Daniela Scorza ◽  
Andrea Carpinteri ◽  
Giovanni Fortese ◽  
Camilla Ronchei ◽  
Sabrina Vantadori ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Low Cycle Fatigue ◽  
Equivalent Strain ◽  
Mean Value ◽  
Multiaxial Fatigue ◽  
Stress Effect ◽  
Mean Stress ◽  
Cycle Fatigue ◽  
Structural Components ◽  
Mean Stress Effect

The goal of the present paper is to discuss the reliability of a strain-based multiaxial Low-Cycle Fatigue (LCF) criterion in estimating the fatigue lifetime of metallic structural components subjected to multiaxial sinusoidal loading with zero and non-zero mean value. Since it is well-known that a tensile mean normal stress reduces the fatigue life of structural components, three different models available in the literature are implemented in the present criterion in order to take into account the above mean stress effect. In particular, such a criterion is formulated in terms of strains by employing the displacement components acting on the critical plane and, then, by defining an equivalent strain related to such a plane. The Morrow model, the Smith-Watson-Topper model and the Manson-Halford model are applied to define such an equivalent strain. The effectiveness of the new formulations is evaluated through comparison with some experimental data reported in the literature, related to biaxial fatigue tests performed on metallic specimens under in-and out-of-phase loadings characterised by non-zero mean stress values.

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