Modelling of temperature and strain rate dependent behaviour of pearlitic steel in block braked railway wheels
Journal article, 2021

Block braked railway wheels are subjected to thermal and rolling contact loading. The thermal loading results in high temperatures and thermal stresses which cause slow time dependent processes such as creep, relaxation and static recovery of the wheel material. At the same time, the rolling contact loading implies a very fast mechanical load application. This paper is focused on material modeling of pearlitic steel for a wide range of loading rates at elevated temperatures. The starting point is a viscoplasticity model including nonlinear isotropic and kinematic hardening. The Delobelle overstress function is employed to capture strain rate dependent response of the material. The model also includes static recovery of the hardening to capture slower viscous (diffusion dominated) behaviour of the material. Experiments for the pearlitic wheel steel ER7 in terms of cyclic strain-controlled uniaxial tests with hold-time, uniaxial ratchetting tests including rapid cycles and biaxial cyclic tests with tension/compression and torsion are used to calibrate the material model. These experiments were performed under isothermal conditions at different temperatures. In the ratchetting tests, higher loading rates are obtained and these have been used to calibrate the high strain rate response of the viscoplasticity model. The paper is concluded with a numerical example of a block braked wheel where the importance of accounting for the viscoplasticity in modelling is highlighted.

Railway wheels

High temperatures

Block braking

Viscoplasticity

Pearlitic steel

Author

Ali Esmaeili

Chalmers, Industrial and Materials Science, Material and Computational Mechanics

Johan Ahlström

Chalmers, Industrial and Materials Science, Engineering Materials

Magnus Ekh

Chalmers, Industrial and Materials Science, Material and Computational Mechanics

Dimitrios Nikas

Chalmers, Industrial and Materials Science, Engineering Materials

Karlstad University

Tore V Vernersson

Chalmers, Mechanics and Maritime Sciences (M2), Dynamics

Railway Engineering Science

2662-4745 (ISSN) 2662-4753 (eISSN)

Vol. 29 4 362-378

Research into enhanced track and switch and crossing system 2 (In2Track-2)

European Commission (EC) (EC/H2020/826255), 2018-11-01 -- 2021-10-31.

Swedish Transport Administration, 2018-11-01 -- 2021-10-31.

Subject Categories

Applied Mechanics

Other Materials Engineering

Vehicle Engineering

DOI

10.1007/s40534-021-00244-z

More information

Latest update

1/9/2024 1