Journal ArticleDOI
Design Evaluation Method for Random Fatigue Based on Spectrum Characteristics
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TLDR
In this paper, the spectral properties of power spectral density (PSD) have been used to evaluate the fatigue damage under random loading, and a simple approximation procedure of high cycle fatigue damage for austenitic stainless steel and ferritic steel has been proposed.Abstract:
This paper shows the new design approach for random fatigue evaluation based on spectral characteristics. Fatigue damage under random loading is usually evaluated according to the following steps: 1. decomposition of random wave to stress amplitude using the rainflow cycle counting method (RFC) 2. evaluation of fatigue damage using Palmgren-Miner’s linear summation rule. In design process, the fluctuation of load is usually characterized through power spectral density (PSD). Therefore, the design process is expected to be generalized if the fatigue damage is directly evaluated from the PSD together with S-N diagram of the material. In fact many properties related to fatigue damage, such as distribution of extreme values, can be derived theoretically from geometrical properties of PSD. However, concerning the distribution of stress amplitude counted by RFC, it is rather difficult to derive it theoretically due to its complicated procedure. In this paper, upper bound of stress amplitude distribution is confirmed for many random waves generated by numerical simulation for many types of PSD. Expressing the upper bound distribution by closed form function using PSD characteristics leads us to the direct evaluation of fatigue damage with safety margin if the fatigue damage by particular stress amplitude is approximated using some series expansion form. Simple approximation procedure of high cycle fatigue damage for austenitic stainless steel and ferritic steel will be proposed in the paper. Finally, design evaluation procedure for the fatigue damage evaluation from PSD together with S-N diagram is summarized.Copyright © 2009 by ASMEread more
References
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Journal ArticleDOI
Mathematical analysis of random noise
TL;DR: In this paper, the authors used the representations of the noise currents given in Section 2.8 to derive some statistical properties of I(t) and its zeros and maxima.
Dissertation
Application of computers in fatigue analysis
TL;DR: In this paper, the authors reviewed and extended some of the recent fatigue analysis methods, including cycle counting methods and methods for prediction of fatigue life to crack initiation, and compared with each other to find out the similarities and differences between them.
Journal ArticleDOI
Spectral methods for lifetime prediction under wide-band stationary random processes
Denis Benasciutti,Roberto Tovo +1 more
TL;DR: In this article, the authors compared numerical results and some analytical prediction formulae available for fatigue damage evaluation; amongst all expressions, a new proposed original approach was shown to give sound theoretical framework and improved results.
Journal ArticleDOI
Cycle distribution and fatigue damage under broad-band random loading
TL;DR: In this paper, the relationship between fatigue assessment and counting methods is investigated by establishing when, in frequency domain analysis, analytical solutions of expected damage are connected with a counting procedure assumption and how this is related to the rainflow counting procedure.
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