Volume 46, Issue 10 pp. 3610-3621
ORIGINAL ARTICLE

The theory of critical distances for random vibration fatigue life analysis of notched specimens

Jiachen Sun

Jiachen Sun

College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China

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Piao Li

Corresponding Author

Piao Li

Department of Civil and Structural Engineering, The University of Sheffield, Sheffield, UK

Correspondence

Piao Li, Department of Civil and Structural Engineering, The University of Sheffield, Sheffield S1 3JD, UK.

Email: [email protected]

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Luca Susmel

Luca Susmel

Department of Civil and Structural Engineering, The University of Sheffield, Sheffield, UK

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First published: 03 July 2023
Citations: 1

Abstract

In this paper, the Theory of Critical Distances (TCD) is reformulated to be employed to estimate random vibration fatigue lifetime of notched components. Using the Point Method argument, the response stress at the critical distance from the notch root is taken as the damage parameter and then used to perform the vibration fatigue life analysis in the presence of geometrical features. First, the finite element simulation is conducted to obtain the response Mises stress power spectrum at the critical distance under the load excitation being investigated. Subsequently, the probability density distribution of the stress amplitude at this position is calculated. Finally, fatigue lifetime is predicted via the parent material S–N curve. In order to check the accuracy of the proposed reformulation of the TCD, a series of random vibration fatigue results were generated by testing notched aluminum alloy specimens under load spectra covering the first-, second-, and third-order natural frequencies. The results from the vibration fatigue tests being performed are seen to be in sound agreement with the predicted lifetimes. This strongly support the idea that the TCD is successful also in predicting random vibration fatigue lifetime of notched components.

Highlights

  • The Theory of Critical Distances (TCD) is reformulated for life prediction.
  • The random vibration fatigue lifetime of notched components is estimated.
  • The FEA is conducted to obtain the stress power spectrum under load excitation.
  • The probability density distribution of the stress amplitude is calculated.

CONFLICT OF INTEREST STATEMENT

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

DATA AVAILABILITY STATEMENT

The data that support the findings of this study are available from the corresponding author upon reasonable request.

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