PSI - Issue 19

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

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

ScienceDirect

Procedia Structural Integrity 19 (2019) 528–537

Fatigue Design 2019 A new modeling framework for fatigue damage of structural components under complex random spectrum Zhu Li a , Ayhan Ince a,b 0 F0 F0 F0 F * a Purdue Polytechnic Institute, Purdue University, West Lafayette, Indiana, USA b Department of Mechanical, Industrial & Aerospace Engineering,Concordia University, Montreal, Quebec, Canada Time and frequency domains-based fatigue damage prediction approaches have been developed over past decades to predict fatigue performance of mechanical structures subjected to random loads. Frequency domain approaches are increasingly being adapted to provide fatigue assessment of mechanical components subjected to random loads due to computational efficiency and cost savings. Current frequency domain damage models only deal with stationary random loadings where Power Spectral Density (PSD) of random loadings does not change in time. However, many machine components, such as jet engines and tracked vehicles are subjected to evolutionary PSD i.e. random-on-random loadings under real service loads. A new fatigue damage modeling framework is proposed to predict fatigue damage of structures under complex evolutionary PSD where the topology of PSD function changes with time. The proposed modeling approach is based on the underlying concept that the evolutionary PSD response of a structure can be decomposed into a finite number of discrete PSDs. Each PSD can be split into narrow frequency bands so that each of narrowbands can be associated with Rayleigh distribution of stress cycles. Fatigue damage can then be predicted by summing up damages for each individual band and each discrete PSD function on the basis of a damage accumulation rule. The proposed modeling approach is numerically and experimentally validated by a finite element method and experiments using three simplified structures made of 5052-H32 aluminum alloy. The proposed approach provides a more efficient and accurate modeling technique, and account for complex random loadings of structural components. Fatigue Design 2019 A new modeling framework for fatigue damage of structural components under complex random spectrum Zhu Li a , Ayhan Ince a,b 0 F0 F0 F0 F * a Purdue Polytechnic Institute, Purdue University, West L fayett , Indiana, USA b Department of Mechanical, Industrial & Aerospace Engineering,Concordia University, Montreal, Quebec, Canada Abstract Time and reque y do ains-based fatig damage prediction approaches hav been develo ed over p st de ades to predict fatigu performance of mechanical s ructur s subjected to random loads. Frequency d main approaches are i cr as ngly bei g adapted to provid fatigue assessment of mechanical components subjec ed to andom loads ue to computational fficiency and cost savings. Current frequency domain damage mod ls only d al with stationary random loadings where Power Spectral Density (PSD) of andom loadings does ot change in time. However, any machine components, such a jet engines and tracked vehic es are subjected to ev lutionary PSD i.e. random-on-random loadings under real serv ce loads. A n w fatigue damage modeli g framework is propos d to predict fatigue amage of structures under complex evoluti ary PSD w ere the t pology of PSD function changes with time. The roposed modeling approach is based on the underlying o c pt that the evolutionary PSD respon e of structure can be decomposed int a finite number of discre e PSDs. Each PSD an be split into n rrow frequency ban s so that each of narrowbands can b ssociated with Rayleigh distribution of stress cy les. Fatigu damage can then b predicted by s mming up damages for e ch individual band and each d scre e PSD function on th basis of a dam ge accumulation rule. T proposed modeling appro ch is numerically nd experimentally validated by a finite element method and xperiments using hree simplified str ctures made o 5052-H32 luminum alloy. The proposed a proach provides a more efficient and accurate modeling technique, and account for complex random loadings of structural components. Abstract

© 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Fatigue Design 2019 Organizers. © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Fatigue Design 2019 Organizers. © 2019 The Autho s. Publ shed by Elsevier B.V. Peer-review under responsibility of the Fatigue Design 2019 Organizers.

Keywords: Fatigue failure; accelerated test; power spectral density; frequency domain; random loading Keywords: Fatigue failure; accelerated test; power spectral density; frequency domain; random loading

* Corresponding author. Tel.: + 1 (514) 848 2424 E-mail address: ayhan.ince@concordia.ca * Correspon ing aut or. Tel.: + 1 (514) 848 2424 E-mail address: ayhan.ince@concordia.ca

2452-3216 © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Fatigue Design 2019 Organizers. 2452-3216 © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Fatigue Design 2019 Organizers.

2452-3216 © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Fatigue Design 2019 Organizers. 10.1016/j.prostr.2019.12.057