Evolution control of cyclic softening of Inconel 718 under isothermal low-cycle fatigue loading by improved calculation of accumulated plastic strain

Šeruga, Domen (author), Nagode, Marko (author), Klemenc, Jernej (author), Doubrava, Karel (author), Bartošák, Michal (author)

In this article, the approach for modelling the stress–strain response of Inconel 718 superalloy under isothermal Low-Cycle Fatigue (LCF) loading using the Prandtl operator approach is improved by introducing an enhanced evolution control of cyclic softening. The proposed improvement consists of an extended calculation of the accumulated plastic strain which now involves an energy conservation step during the calculation. The simulation power of the Prandtl model is especially improved in the area of increasing low plastic strain range magnitudes which are consistently evolving without regard to the variably changing loading regime. The prediction capability of the proposed model is demonstrated especially for block load tests where the highest discrepancies have been observed before the improvement. Evaluation of the agreement between the experimental observations and the simulations shows up to 6 % better agreement using the improved evolution control of cyclic softening.

• Language: English
• Keywords: Prandtl operators, low-cycle fatigue, plasticity, nickel-based superalloy, Inconel 718
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Author Accepted Manuscript
• Year: 2025
• Number of pages: 11 str.
• Numbering: Vol. 218, pt. A, art. 105583
• PID: 20.500.12556/RUL-171166
• UDC: 620.178.3:669.018.2
• ISSN on article: 0308-0161
• DOI: 10.1016/j.ijpvp.2025.105583
• COBISS.SI-ID: 245631747
• Publication date in RUL: 14.08.2025

Record is a part of a journal

• Title: International journal of pressure vessels and piping
• Shortened title: Int. j. press. vessels piping
• Publisher: Elsevier
• ISSN: 0308-0161
• COBISS.SI-ID: 8917765

Licences

• License: CC BY-NC-ND 4.0, Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
• Link: http://creativecommons.org/licenses/by-nc-nd/4.0/
• Description: The most restrictive Creative Commons license. This only allows people to download and share the work for no commercial gain and for no other purposes.

Projects

• Funder: ARRS - Slovenian Research Agency
• Project number: P2-0182
• Name: Razvojna vrednotenja

• Funder: Czech Science Foundation
• Project number: 21-06645S