Calculation of plastic notch stress intensity factor and strain energy density by Peak Stress Method under low-cycle fatigue conditions

Šeruga, Domen (author), Campagnolo, Alberto (author), Klemenc, Jernej (author), Meneghetti, Giovanni (author)

In this article, an idea for prediction of low-cycle fatigue durability of notched components is presented. The concept implements the Peak Stress Method into the calculation of both the plastic notch stress intensity factor and averaged elasto-plastic strain energy density. The scatter reduction which is characteristic for the approach using the strain energy density calculation under high-cycle fatigue conditions is less pronounced in the low-cycle fatigue area. Importantly, the otherwise changed slope of the durability curve in the low-cycle fatigue regime of the material remains almost equal to the slope in the high-cycle fatigue regime of the material using the implemented method. The method has been validated on tension–compression testing of plain and V-notched specimens of structural steel St-52 with three notch angles: 35°, 90° and 135°. It is shown that significant agreement can be drawn between predictions using the Peak Stress Method and finite element evaluation of the averaged strain energy density.

• Language: English
• Keywords: low-cycle fatigue, peak stress method, plasticity, strain energy density, structural steel St-52
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2026
• Number of pages: 13 str.
• Numbering: Vol. 142, art. 105396
• PID: 20.500.12556/RUL-177578
• UDC: 620.178.3:669.1
• ISSN on article: 0167-8442
• DOI: 10.1016/j.tafmec.2025.105396
• COBISS.SI-ID: 262910979
• Publication date in RUL: 24.12.2025

Record is a part of a journal

• Title: Theoretical and applied fracture mechanics
• Shortened title: Theor. appl. fract. mech.
• Publisher: North-Holland
• ISSN: 0167-8442
• COBISS.SI-ID: 825366

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.

Secondary language

• Language: Slovenian
• Keywords: malociklično utrujanje, metoda konic napetosti, plastičnost, deformacijska energija, konstrukcijsko jeklo

Projects

• Funder: EC - European Commission
• Name: Erasmus+ Staff mobility

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: P2-0182
• Name: Razvojna vrednotenja