Modelling of grey cast iron for application to brake discs for heavy vehicles
Artikel i vetenskaplig tidskrift, 2017

Cast iron brake discs are commonly used in the automotive industry, and efforts are being made to gain a better understanding of the thermal and mechanical phenomena occurring at braking. The high thermomechanical loading at braking arises from interaction between the brake disc and the brake pads. Frictional heating generates elevated temperatures with a non-uniform spatial distribution often in the form of banding or hot spotting. These phenomena contribute to material fatigue and wear and possibly also to cracking. The use of advanced calibrated material models is one important step towards a reliable analysis of the mechanical behaviour and the life of brake discs. In the present study, a material model of the Gurson-Tvergaard-Needleman type is adopted, which accounts for asymmetric yielding in tension and compression, kinematic hardening effects, viscoplastic response and temperature dependence. The material model is calibrated using specimens tested in uniaxial cyclic loading for six different temperatures ranging from room temperature to 650 °C. A special testing protocol is followed which is intended to activate the different features of the material model. Validation of the model is performed by using tensile tests and thermomechanical experiments. An application example is given where a 10° sector of a brake disc is analysed using the commercial finitie element code Abaqus under a uniformly applied heat flux on the two friction surfaces. The results indicate that the friction surface of the hat side and the neck can be critical areas with respect to fatigue for the uniform heating studied.

laboratory experiments

elevated temperatures

material model

finite element model

cast iron

Brake disc

Författare

Gael le Gigan

Chalmers, Tillämpad mekanik, Dynamik

Magnus Ekh

Chalmers, Tillämpad mekanik, Material- och beräkningsmekanik

Tore V Vernersson

Chalmers, Tillämpad mekanik, Dynamik

Roger Lundén

Chalmers, Tillämpad mekanik, Dynamik

Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering

0954-4070 (ISSN)

Vol. 231 35-49

Ämneskategorier

Farkostteknik

DOI

10.1177/0954407016632090