scholarly journals Continuous Crack Growth Monitoring and Residual Life Prediction under Variable-amplitude Loading Conditions

2014 ◽  
Vol 74 ◽  
pp. 343-346 ◽  
Author(s):  
Matteo Corbetta ◽  
Claudio Sbarufatti ◽  
Andrea Manes ◽  
Marco Giglio
Keyword(s):  
Crack Growth ◽  
Life Prediction ◽  
Residual Life ◽  
Growth Monitoring ◽  
Loading Conditions ◽  
Variable Amplitude Loading ◽  
Variable Amplitude ◽  
Continuous Crack ◽  
Residual Life Prediction

Fatigue crack growth prediction model under variable amplitude loading conditions

2021 ◽  
pp. 105678952199873
Author(s):  
Menghan Li ◽  
Xin Liu ◽  
Zhenguo Li ◽  
Yingbo Zhang
Keyword(s):  
Crack Growth ◽  
Life Prediction ◽  
Stress Ratio ◽  
Crack Size ◽  
Model Parameters ◽  
Remaining Life ◽  
Variable Loading ◽  
Variable Amplitude Loading ◽  
Variable Amplitude ◽  
Crack Growth Model

Crack size prediction under variable amplitude loading is a very complex process, which is also important for life prediction in engineering. A crack growth model considering different stress ratio for fatigue remaining life prediction is proposed in this paper. The model utilizes stress ratio to describe the variable loading sequences, which makes the calculation greatly simplified. The rain-flow method is utilized to characterize the load sequence effects under variable amplitude loading. In addition, particle filter is utilized to estimate the model parameters describing the crack growth. Finally, case study indicates that the proposed approach is efficient in predicting crack growth and fatigue remaining life.

A Modified Compliance Method for Automatically Measuring Fatigue Crack Growth In Situ during Spectrum Fatigue Testing

2014 ◽  
Vol 891-892 ◽  
pp. 732-738
Author(s):  
Wyman Zhuang ◽  
Qian Chu Liu
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Operating Conditions ◽  
Loading Conditions ◽  
Variable Amplitude Loading ◽  
Variable Amplitude ◽  
Marker Band ◽  
Spectrum Loading

The fatigue critical structures of military aircraft are generally subjected to variable amplitude flight spectrum loading. Maintaining aircraft structural integrity to ensure safe operation of the fleet is critically dependent on accurate analysis and reliable prediction of fatigue crack growth in those structures under service operating conditions. To achieve this goal, laboratory experimental methods that can accurately measure and monitor fatigue crack growth under variable amplitude loading are required. This can be challenging as no test standard exists to guide the process of fatigue crack growth measurement under variable amplitude loading conditions to ensure the accuracy of the test results. This challenge was addressed by developing a modified compliance method as described in this paper. The results presented employed a modified compliance method complemented with a travelling microscope technique and marker band loads. The modified compliance method developed is able to measure in-situ, fatigue crack growth of standard compact-tension specimens under a fighter flight spectrum loading. The marker band loads and microscope readings were used to assist the post-test validation using quantitative fractography. The results from this study have demonstrated that the modified compliance method can produce consistent and accurate fatigue crack growth data under variable amplitude loading conditions.

Analytical Concepts for Recent Development in Fatigue Crack Growth under Variable Amplitude Loading. Part I: Qualitative Interpretation

2011 ◽  
Vol 462-463 ◽  
pp. 59-64 ◽  
Author(s):  
N. Nik Abdullah ◽  
M. Hadi Hafezi ◽  
Shahrum Abdullah
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Life Prediction ◽  
Local Stress ◽  
Theoretical Background ◽  
Effective Parameters ◽  
Variable Amplitude Loading ◽  
Variable Amplitude ◽  
Qualitative Interpretation

Understanding effective parameters in fatigue crack growth (FCG) model under variable amplitude loading (VAL) is of eminent importance theoretically as well as experimentally. In response to this necessity, a systematic study of different analytical concepts and loading sequences in order to gain a practical framework has been proposed. The theoretical background related to the fatigue life prediction by using FCG model has been presented. This has shown the rationale of why we need to calculate local stress-strain in the crack tip in developing FCG models which is the main subject of this research.

Application of the Strip Yield Model to Crack Growth Predictions for Structural Steel

2010 ◽  
Vol 57 (1) ◽  
pp. 1-20
Author(s):  
Małgorzata Skorupa ◽  
Tomasz Machniewicz
Keyword(s):  
Structural Steel ◽  
Crack Growth ◽  
Model Calibration ◽  
Load History ◽  
Yield Model ◽  
Variable Amplitude Loading ◽  
Variable Amplitude ◽  
Constraint Factors ◽  
Strip Yield Model ◽  
Closure Mechanism

Application of the Strip Yield Model to Crack Growth Predictions for Structural SteelA strip yield model implementation by the present authors is applied to predict fatigue crack growth observed in structural steel specimens under various constant and variable amplitude loading conditions. Attention is paid to the model calibration using the constraint factors in view of the dependence of both the crack closure mechanism and the material stress-strain response on the load history. Prediction capabilities of the model are considered in the context of the incompatibility between the crack growth resistance for constant and variable amplitude loading.

Residual life prediction for surface cracks in complex structural details

1975 ◽  
Vol 12 (4) ◽  
pp. 369-375 ◽  
Author(s):  
Thomas A. Cruse ◽  
Philip M. Besuner
Keyword(s):  
Life Prediction ◽  
Residual Life ◽  
Surface Cracks ◽  
Structural Details ◽  
Residual Life Prediction ◽  
Complex Structural
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