Modelling of temperature and strain rate dependent behaviour of pearlitic steel in block braked railway wheels
Artikel i vetenskaplig tidskrift, 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.

Block braking

High temperatures

Pearlitic steel

Viscoplasticity

Railway wheels

Författare

Ali Esmaeili

Chalmers, Industri- och materialvetenskap, Material- och beräkningsmekanik

Johan Ahlström

Chalmers, Industri- och materialvetenskap, Konstruktionsmaterial

Magnus Ekh

Chalmers, Industri- och materialvetenskap, Material- och beräkningsmekanik

Dimitrios Nikas

Chalmers, Industri- och materialvetenskap, Konstruktionsmaterial

Karlstads universitet

Tore V Vernersson

Chalmers, Mekanik och maritima vetenskaper, Dynamik

RAILWAY ENGINEERING SCIENCE

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

Vol. In Press

In2Track-2 (CHARMEC EU19)

Europeiska kommissionen (EU) (EC/H2020/826255), 2018-11-01 -- 2021-10-31.

Trafikverket, 2018-11-01 -- 2021-10-31.

Ämneskategorier

Teknisk mekanik

Annan materialteknik

Farkostteknik

DOI

10.1007/s40534-021-00244-z

Mer information

Senast uppdaterat

2021-08-19