PSI - Issue 21

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 21 (2019) 154–165

© 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 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials organizers © 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 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials organizers Abstract In this study, a regression analysis model has been developed to calculate the fatigue life of open-hole specimens with a double through cracks without significantly compromising on the accuracy. I the first phase of the study, experimen al fatigue life data for open-hole 2024-T3 aluminum specimens with double through the thickness cracks is extract d f om experimental tes data Life ass ssment model corr sp nding to the experimental data is generated using the Forma equation to fit th da/dN vs delta K crack growth data, and mate ial constants and plane stress intensity factor of 2024-T3 alloy in th Forman equation re obtained. Extended finit element me od (XFEM) h s then be n employed to model the same open-hole s ecime geom try with a double through the th ckness cracks to che k the accuracy of th XFEM esults with the experim ntal fatigue life data. XFEM simulation f r th crack growth and determination of the str ss i tensity factor during the crack propagation has been performed for different combinations of th initial crack length, riv t hole iameter and applied far field stress utilizing design of experime ts based n Response Surface (RS) m tho . Utilizing the transformed fatigue life results obtained by the XFEM method, a regression analysis of the RS experiments has been performed and a regression model capable of acceptable life prediction of open hole specimens with DTC has been developed. © 2019 The Autho s. Publ shed 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 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials organizers 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials Development of a regression model for the life assessment of open hole specimens with double through cracks utilizing stress intensity factor calculations via XFEM S.Sohrab Heidari Shabestari a, b * and Altan Kayran a a Department of Aerospace Engineering,Middle East Technical University, Ankara 06800, Turkey b Barida Engineering and Automation Solutions, Bursa 16280, Turkey Abstract In this study, a regression analysis model has been developed to calculate the fatigue life of open-hole specimens with a double through cracks without significantly compromising on the accuracy. In the first phase of the study, experimental fatigue life data for open-hole 2024-T3 aluminum specimens with double through the thickness cracks is extracted from experimental test data. Life assessment model corresponding to the experimental data is generated using the Forman equation to fit the da/dN vs delta K crack growth data, and material constants and plane stress intensity factor of 2024-T3 alloy in the Forman equation are obtained. Extended finite element method (XFEM) has then been employed to model the same open-hole specimen geometry with a double through the thickness cracks to check the accuracy of the XFEM results with the experimental fatigue life data. XFEM simulation for the crack growth and determination of the stress intensity factor during the crack propagation has been performed for different combinations of the initial crack length, rivet hole diameter and applied far field stress utilizing design of experiments based on Response Surface (RS) method. Utilizing the transformed fatigue life results obtained by the XFEM method, a regression analysis of the RS experiments has been performed and a regression model capable of acceptable life prediction of open hole specimens with DTC has been developed. 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials Development of a regression m del for the life asses m nt of open hole specimens with d uble through cracks utilizing stress intensity f ctor calculations via XFEM S.Sohrab Heidari Shabestari a, b * and Altan Kayran a a Department of Aerospace Engineering,Middle East Technical University, Ankara 06800, Turkey b Barida Engineering and Automation Solutions, Bursa 16280, Turkey Keywords: Fatigue Life Assessment, Regression Model, XFEM, Double Through the Thickness Cracks

Keywords: Fatigue Life Assessment, Regression Model, XFEM, Double Through the Thickness Cracks

* Corresponding author. Tel.: +90-553-714-2990; E-mail address: e199369@metu.edu.tr * Corresponding author. Tel.: +90-553-714-2990; E mail address: e199369@met .edu.tr

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 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials 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 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials 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 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials organizers 10.1016/j.prostr.2019.12.097