PSI - Issue 72

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ScienceDirect

Procedia Structural Integrity 72 (2025) 499–506

12th Annual Conference of Society for Structural Integrity and Life (DIVK12) Study on optimisation-based approach conducted to estimate the life to failure of the damaged aircraft structure exposed to complex thermo-mechanical loading Nenad Vidanović a, *, Aleksandar Grbović b , Gordana Kastratović a , Aleksandar Sedmak b Abstract In this study, the use of established numerical optimisation-based framework was justified for fatigue remaining life prediction of damaged aircraft component exposed to fatigue loads during flight at cruising speed. The aircraft component which was analysed is the high-pressure turbine (HPT) casing of a turbofan engine made of Inconel 718. A numerical approach based on finite element methods (FEM) and response surface optimisation (RSO) was suggested and then applied to obtai n Paris’ coefficients C & which then were used to evaluate fatigue remaining life of HPT casing and estimate the risk of its further use. © 2026 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Aleksandar Sedmak, Branislav Djordjevic, Simon Sedmak Dr. Simon Sedmak, ssedmak@mas.bg.ac.rs, Innovation Center of Faculty of Mechanical Engineering, Belgrade, Serbia a University of Belgrade, Faculty of Transport and Traffic Engineering, Vojvode Stepe 305, 11000 Belgrade, Serbia b University of Belgrade, Faculty of Mechanical Engineering, Kraljice Marije 16, 11000 Belgrade, Serbia

Keywords: Paris ’ coefficiens determination; Surrogat -based optimisation; Fatigue remaining life

1. Introduction The root cause of the casing damage was discovered during a simple failure analysis in the Maintenance, repair and operations (MRO) workshop where the unskilled use of electrical discharge machining (EDM) was identified. Specifically, this treatment was used to make 9 surface marks (notches) with depths between 0.11 and 2.46 mm, and they were cut through the flange into the parent material at the rear sides of the cooling holes. Before the marks were

* Corresponding author. Tel.: +381-11-3091-259; fax: +381-11-3096-704. E-mail address: n.vidanovic@sf.bg.ac.rs

2452-3216 © 2026 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Aleksandar Sedmak, Branislav Djordjevic, Simon Sedmak Dr. Simon Sedmak, ssedmak@mas.bg.ac.rs, Innovation Center of Faculty of Mechanical Engineering, Belgrade, Serbia 10.1016/j.prostr.2025.08.132