PSI - Issue 24

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000–000

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 24 (2019) 398–407

© 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the AIAS2019 organizers Abstract In this paper, the variance of fatigue damage under stationary random loadings is investigated by means of different case studies (linear oscillator system, random process with ideal unimodal or bimodal power spectral density). Monte Carlo method is used to evaluate the variance of fatigue damage in time-domain and frequency-domain approach. The variance from simulations is compared with analytical methods (e.g. Mark and Crandall’s method, Bendat’s method and Low’s method). Furthermore, for each case study, the paper investigates the relationship between the variance of fatigue damage and the bandwidth parameters. The purpose is to provide a simple closed-form solution for the case of ideal unimodal power spectral density. The closed-form solution has been compared with Monte Carlo simulation in time-domain. The results show good agreement not only for narrow band but also for wide-band process. © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the AIAS2019 organizers AIAS 2019 International Conference on Stress Analysis Variance of fatigue damage in stationary random loadings: comparison between time- and frequency-domain results Julian Marcell Enzveiler Marques a, *, Denis Benasciutti a , Roberto Tovo a a Department of Engineering, University of Ferrara, via Saragat 1, 44122, Ferrara, Italy Abstract In this paper, the variance of fatigue damage under stationary random loadings is investigated by means of different case studies (linear oscillator system, random process with ideal unimodal or bimodal power spectral density). Monte Carlo method is used to evaluate the variance of fatigue damage in time-domain and frequency-domain approach. The variance from simulations is compared with analytical methods (e.g. Mark and Crandall’s method, Bendat’s method and Low’s method). Furthermore, for each case study, the paper investigates the relationship between the variance of fatigue damage and the bandwidth parameters. The purpose is to provide a simple closed-form solution for the case of ideal unimodal power spectral density. The closed-form solution has been compared with Monte Carlo simulation in time-domain. The results show good agreement not only for narrow band but also for wide-band process. © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the AIAS2019 organizers AIAS 2019 International Conference on Stress Analysis Variance of fatigue damage in stationary random loadings: comparison between time- and frequency-domain results Julian Marcell Enzveiler Marques a, *, Denis Benasciutti a , Roberto Tovo a a Department of Engineering, University of Ferrara, via Saragat 1, 44122, Ferrara, Italy Keywords: Random loadings; Time-domain approach; Frequency-domain approach; Fatigue damage; Variance of fatigue damage Keywords: Random loadings; Time-domain approach; Frequency-domain approach; Fatigue damage; Variance of fatigue damage 1. Introduction Failures of engineering components or structures may occur as an effect of applied uniaxial random loadings. In a frequency-domain approach, a random process is characterized by a Power Spectral Density (PSD). Analytical expressions are available for estimating the expected damage directly from PSD (Benasciutti and Tovo (2005)). Alternatively, the time-domain approach is based on well-established procedures (rainflow counting method and 1. Introduction Failures of engineering components or structures may occur as an effect of applied uniaxial random loadings. In a frequency-domain approach, a random process is characterized by a Power Spectral Density (PSD). Analytical expressions are available for estimating the expected damage directly from PSD (Benasciutti and Tovo (2005)). Alternatively, the time-domain approach is based on well-established procedures (rainflow counting method and

* Corresponding author. Tel.: +39-0532-974104; fax.: +39-0532-974870 E-mail address: nzvjnm@unife.it * Corresponding author. Tel.: +39-0532-974104; fax.: +39-0532-974870 E-mail address: nzvjnm@unife.it

2452-3216 © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the AIAS2019 organizers 2452-3216 © 2019 The Authors. Published by Elsevier B.V. This is an ope access article under t CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the AIAS2019 organizers

2452-3216 © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the AIAS2019 organizers 10.1016/j.prostr.2020.02.037