Thermomechanical fatigue of grey cast iron brake discs for heavy vehicles
Review article, 2019

The development of fatigue life assessment models for vehicle components exposed to thermomechanical fatigue supports the establishing of adequate maintenance intervals that neither cause unnecessary vehicle downtime, nor jeopardize the function of the components. In modern automotive applications, braking is closely related to safety and is commonly performed with disc brakes. Failure here may result in structural damage or even breakdown and loss of lives. In the present work, the cyclic response of grey cast iron is analysed and the fatigue life of brake discs made from this material is studied by use of four different fatigue life assessment models: the Smith–Watson–Topper model, the Coffin–Manson model and two mechanism-based damage models. Results from isothermal and thermomechanical experiments on uniaxially loaded specimens are used for calibration of the models. Finally, the models are used to assess the life of a brake disc for a simulated brake dynamometer experiment. It is found that the fatigue model parameters that are calibrated using different sets of isothermal uniaxial test data show a substantial spread. A comparison with results from full-scale brake rig experiments shows that predictions by any of the models that have been calibrated using data from a well-designed thermomechanical test are in reasonable agreement with the estimated crack initiation phase for actual brake disc lives. It can be concluded that it is not sufficient to calibrate the studied fatigue life models using isothermal uniaxial tests for predictions of thermomechanical fatigue lives.

cast iron

fatigue life assessment models

Disc braking

laboratory experiments

thermomechanical fatigue

Author

Gael le Gigan

Chalmers, Mechanics and Maritime Sciences, Dynamics

Viktor Norman

Linköping University

Johan Ahlström

Chalmers, Industrial and Materials Science, Engineering Materials

Tore V Vernersson

Chalmers, Mechanics and Maritime Sciences, Dynamics

ÅF AB

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

0954-4070 (ISSN)

Vol. 233 2 453-467

Subject Categories

Applied Mechanics

Infrastructure Engineering

Vehicle Engineering

DOI

10.1177/0954407017739723

More information

Latest update

3/4/2019 9