Anisotropic yield surfaces after large shear deformations in pearlitic steel
Artikel i vetenskaplig tidskrift, 2020

Rolling contact fatigue often initiates in the highly deformed surface layer of railway rails. However, the behavior of pearlitic rail steels, subjected to such large shear strains, is not well known. Due to buckling, it is not possible to obtain the large shear deformation with tubular test bars. We have, therefore, developed a novel experimental methodology. Large shear strains (up to 1.13) were obtained by twisting cylindrical solid test bars under a compressive axial load. After that, these bars were re-machined into thin-walled tubular test bars. The remachined bars were then used to characterize the behavior of the deformed material. Changes in both the elastic and plastic responses are observed, quantified, and discussed. We evaluate the ability of different yield criteria to model the experimentally measured yield surfaces. Three anisotropic yield criteria are considered: Hill (1948), Barlat's yld2004-18p, and Karafillis and Boyce (1993). The accuracies of these criteria are evaluated and compared to the estimated experimental uncertainty. Furthermore, cross-validation is used to investigate the predictive abilities of the yield criteria. It turns out that the Hill yield criterion fits and predicts the experimental data very well. Finally, the evolution of yield surfaces is found to be strongly dependent on the amount of plastic deformation defining the yield limit.

Pearlitic steel

Evolving anisotropy

Mechanical testing

Yield criterion


Knut Andreas Meyer

Chalmers, Industri- och materialvetenskap, Material- och beräkningsmekanik

Magnus Ekh

Chalmers, Industri- och materialvetenskap, Material- och beräkningsmekanik

Johan Ahlström

Chalmers, Industri- och materialvetenskap, Konstruktionsmaterial

European Journal of Mechanics, A/Solids

0997-7538 (ISSN)

Vol. 82 103977

Inverkan av anisotropi på utmattningsprickor under rullkontakt (CHARMEC MU34)

Chalmers järnvägsmekanik (CHARMEC), 2015-05-18 -- 2020-05-15.

Europeiska kommissionen (EU), 2015-05-18 -- 2020-05-15.

In2Track-2 (CHARMEC EU19)

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

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



Teknisk mekanik

Annan materialteknik



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