Critical plane-based fatigue life model under multiaxial random loading
International Journal of Structural Integrity
ISSN: 1757-9864
Article publication date: 8 August 2022
Issue publication date: 12 September 2022
Abstract
Purpose
Engineering components/structures are usually subjected to complex and variable loads, which result in random multiaxial stress/strain states. However, fatigue analysis methods under constant loads cannot be directly applied to fatigue life prediction analysis under random loads. Therefore, the purpose of this study is how to effectively evaluate fatigue life under multiaxial random loading.
Design/methodology/approach
First, the average phase difference is characterized as the ratio of the number of shear strain cycles to the number of normal strain cycles, and the new non-proportional additional hardening factor is proposed. Then, the determined random typical load spectrum is processed into a simple variable amplitude load spectrum, and the damage in each plane is calculated according to the multiaxial fatigue life prediction model and Miner theory. Meanwhile, the cumulative damage can be calculated separately by projection method. Finally, the maximum projected cumulative damage plane is defined as the critical plane of multiaxial random fatigue.
Findings
The fatigue life prediction capability of the method is verified based on test data of TC4 titanium alloy under random multiaxial loading. Most of the predicting results are within double scatter bands.
Originality/value
The objective of this study is to provide a reference for the determination of critical plane and non-proportional additional hardening factor under multiaxial random loading, and to promote the development of multiaxial fatigue from experimental studies to practical engineering applications.
Keywords
Acknowledgements
Lanzhou Talents Innovation and entrepreneurship Project [2021-RC-23] and Hongliu Youth Fund of Lanzhou University of Technology.
Citation
Wang, J., Liu, J., Hua, F., He, Y. and Wang, X. (2022), "Critical plane-based fatigue life model under multiaxial random loading", International Journal of Structural Integrity, Vol. 13 No. 5, pp. 845-856. https://doi.org/10.1108/IJSI-06-2022-0083
Publisher
:Emerald Publishing Limited
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