The whole fatigue life prediction of Ni-based single crystal super-alloy specimen with single hole based on EIFS and ‘Fish-eye’ theory

A method of predicting the fatigue life under multiaxis loads based on the Paris law and EIFS was proposed. And the fatigue life under different loading stress and stress ratio were investigated. The results show that when the loading stress increased from 450~800 MPa, the fatigue life decreased from 6762379 to 10056, as well as when the stress ratio increased from 0.1~1, the fatigue life increased from 6762379 to 14932368. It was validated by test eventually. And the fatigue life model presented here agrees well with test results. It is significant to the prediction of turbine of Ni-based single crystal super-alloy material with filming hole.

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Investigation on Stress and Strain of Ni-Based Single Crystal Super-Alloy Specimen with Single Hole Based on Abacus

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.891.17 ◽

2021 ◽

Vol 891 ◽

pp. 17-22

Author(s):

Xiang Zhen Xue ◽

Zhi Xun Wen ◽

Wen Xian Li

Keyword(s):

Fatigue Life ◽

Single Crystal ◽

High Reliability ◽

Turbine Blades ◽

High Strength ◽

Initial Crack ◽

Alloy Specimen ◽

Single Hole ◽

Stress Ratios ◽

Super Alloy

The Miss stress, Max.principal strain and Magnitude displacement have important influence on the fatigue life of the Ni-based single crystal super-alloy turbine blades. This work investigated The Miss stress, Max.principal strain and Magnitude displacement of Ni-based single crystal super-alloy specimen with single hole along dangerous path under different working conditions by Abacus. The results show that the initial crack length and loading stresses are larger, the crack growth on the specimen is faster, and then, the fatigue life is the shorter. Moreover, for the different stress ratios, smaller stress ratio can lead to lower fatigue life. The result is significant to design turbine of Ni-based single crystal super-alloy of high accuracy, high reliability and high strength.

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A Fatigue Life Prediction Model Based on Modified Resolved Shear Stress for Nickel-Based Single Crystal Superalloys

Metals ◽

10.3390/met9020180 ◽

2019 ◽

Vol 9 (2) ◽

pp. 180 ◽

Cited By ~ 2

Author(s):

Jialiang Wang ◽

Dasheng Wei ◽

Yanrong Wang ◽

Xianghua Jiang

Keyword(s):

Shear Stress ◽

Fatigue Life ◽

Prediction Model ◽

Single Crystal ◽

Life Prediction ◽

Stress Amplitude ◽

Damage Parameter ◽

Fatigue Life Prediction ◽

Model Based ◽

Life Prediction Model

In this paper, the viewpoint that maximum resolved shear stress corresponding to the two slip systems in a nickel-based single crystal high-temperature fatigue experiment works together was put forward. A nickel-based single crystal fatigue life prediction model based on modified resolved shear stress amplitude was proposed. For the four groups of fatigue data, eight classical fatigue life prediction models were compared with the model proposed in this paper. Strain parameter is poor in fatigue life prediction as a damage parameter. The life prediction results of the fatigue life prediction model with stress amplitude as the damage parameter, the fatigue life prediction model with maximum resolved shear stress in 30 slip directions as the damage parameter, and the McDiarmid (McD) model, are better. The model proposed in this paper has higher life prediction accuracy.

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