Tensile Fatigue and Life Prediction of a SiC/SiC Composite

2001 ◽  
Author(s):  
Jun Shi
Keyword(s):  
Fatigue Life ◽  
High Frequency ◽  
Life Prediction ◽  
Low Frequency ◽  
Fatigue Life Prediction ◽  
Test Results ◽  
R Ratio ◽  
Tensile Fatigue ◽  
Stiffness Variation ◽  
Underlying Mechanisms

This paper summaries two sets of tension-tension fatigue results. The first set corresponds to low R ratio (0.1) and low frequency (1Hz), whereas the second set covers high R ratio (0.9) and high frequency (10Hz). For the former, detailed analysis of stress strain loops is conducted in connection with the underlying mechanisms that govern fatigue deformation and life. For the latter only stiffness variation with fatigue cycles is discussed. The test results are also examined for their impact on fatigue life prediction.

scholarly journals Application of Life-Dependent Material Parameters to Fatigue Life Prediction under Multiaxial and Non-Zero Mean Loading

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1587 ◽  
Author(s):  
Krzysztof Kluger ◽  
Aleksander Karolczuk ◽  
Szymon Derda
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
Fatigue Loading ◽  
Mean Value ◽  
Multiaxial Fatigue ◽  
Fatigue Life Prediction ◽  
Test Results ◽  
Material Parameters ◽  
Fixed Material ◽  
Stress Ratios

This study presents the life-dependent material parameters concept as applied to several well-known fatigue models for the purpose of life prediction under multiaxial and non-zero mean loading. The necessity of replacing the fixed material parameters with life-dependent parameters is demonstrated. The aim of the research here is verification of the life-dependent material parameters concept when applied to multiaxial fatigue loading with non-zero mean stress. The verification is performed with new experimental fatigue test results on a 7075-T651 aluminium alloy and S355 steel subjected to multiaxial cyclic bending and torsion loading under stress ratios equal to R = −0.5 and 0.0, respectively. The received results exhibit the significant effect of the non-zero mean value of shear stress on the fatigue life of S355 steel. The prediction of fatigue life was improved when using the life-dependent material parameters compared to the fixed material parameters.

Determination Method of a Proper Small-Load-Omitting Criterion Based on the Extreme Load

2013 ◽  
Vol 694-697 ◽  
pp. 278-283
Author(s):  
Zhi Qiang Xu
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
High Frequency ◽  
Life Prediction ◽  
Time History ◽  
Fatigue Life Prediction ◽  
Threshold Theory ◽  
Small Load ◽  
Extreme Load ◽  
Peak Over Threshold

A crucial step to obtain a reliable fatigue life prediction is to determine a proper small load threshold below which the cycles at small loads or stresses with high frequency causing little fatigue damage are truncated from the original load time history. By taking both the peak over threshold theory and the endurance limit threshold into account, a proper small load threshold is proposed in this paper. The optimal threshold should be high enough to remove the high-frequency small cycles and low enough to minimize the loss of the fatigue damage which maybe be truncated by the empirical small-load omitting threshold. Based on this proper threshold, the fatigue life prediction will be more reliable.

Study on the Test of Fatigue Life Prediction for X80 Line Pipe

2014 ◽  
Vol 692 ◽  
pp. 387-390
Author(s):  
Qiu Rong Ma ◽  
Yang Li ◽  
Kun Yang
Keyword(s):  
Fatigue Crack ◽  
Fatigue Life ◽  
Crack Propagation ◽  
Life Prediction ◽  
Safety Margin ◽  
Fatigue Life Prediction ◽  
Test Results ◽  
Line Pipe ◽  
Work Condition ◽  
Submerged Arc

This paper researched the test of fatigue crack propagation of grade X80 submerged arc welded pipes. According to the test results, analyzed and calculated the fatigue life of submerged arc welded pipes for X80 with half elliptical crack defects at the simulated work condition of shutdown. On a single simulated work condition, the fatigue life of submerged arc welded pipes for X80 with Ф1219×22.0mm is 62 years, which had enough safety margin for fatigue life.

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