Evaluations and enhancements of fatigue crack initiation criteria for steels subjected to large shear deformations
Artikel i vetenskaplig tidskrift, 2024

While large accumulated plastic deformations occur in the rail surface layer where rolling contact fatigue cracks initiate, many available Low Cycle Fatigue (LCF) crack initiation criteria focus on small plastic strains. Accordingly, this paper evaluates available fatigue crack initiation criteria for highly shear-deformed R260 steels, reflecting the conditions in the surface layer of rails. Furthermore, modified crack initiation criteria are suggested. The evaluation is based on three different experiments: Large shear strain increments under varying axial loading (predeformation), strain-controlled LCF tests after some predeformation, and axial High Cycle Fatigue (HCF) experiments. For the predeformation, Finite Element (FE) simulations, with a large-strain plasticity model for cyclic and distortional hardening, provide predictions of the local stress and strain histories. A cross-validation procedure is used to assess the accuracy and reliability of both established and modified fatigue crack initiation criteria. The proposed modifications to one of the criteria show an improved fit to the experimental data. However, there is a tendency to overfitting, which can be improved by including more experimental data.

Anisotropy

Finite element simulations

Crack initiation criteria

Tension–torsion tests

Large deformations

Författare

Nasrin Talebi

Chalmers, Industri- och materialvetenskap, Material- och beräkningsmekanik

Johan Ahlström

Chalmers, Industri- och materialvetenskap, Konstruktionsmaterial

Magnus Ekh

Chalmers, Industri- och materialvetenskap, Material- och beräkningsmekanik

Knut Andreas Meyer

Technische Universität Braunschweig

International Journal of Fatigue

0142-1123 (ISSN)

Vol. 182 108227

Driving research and innovation to push Europe's rail system forward (IN2TRACK3)

Trafikverket (2021/19114), 2021-01-01 -- 2023-12-31.

Europeiska kommissionen (EU) (EC/H2020/101012456), 2021-01-01 -- 2023-12-31.

IAM4RAIL

Trafikverket (2023/9635), 2023-01-01 -- 2026-02-28.

Ämneskategorier

Teknisk mekanik

Metallurgi och metalliska material

DOI

10.1016/j.ijfatigue.2024.108227

Mer information

Senast uppdaterat

2024-03-11