Keywords: tread braking, twin-disc, scaling technique, brake shoe, contact mechanics, FE thermal modelling.

Tread braking remains the most widely adopted solution for freight trains due to its robustness and low cost, despite its complex thermo-mechanical behaviour. The frictional contact between brake blocks and wheel treads generates cyclic thermal loads that may lead to material degradation, thermal fatigue, and crack initiation. This paper presents recent developments by the Politecnico di Torino in the investigation of wheel-shoe interaction, achieved through both experimental and numerical approaches. As a key contribution, the research team has designed and built an innovative scaled twin-disc test rig, that relies on a dedicated thermal similitude rule, ensuring that the temperature field on the scaled device corresponds to the one that would be obtained on the full-scale system. The experimental setup can be integrated with different sensors, i.e., thermal image camera and a battery of pyrometers, to obtain the temperature field with high resolution and sampling rate. In parallel, the research group has been working on the development of numerical thermal models for the brake block and wheel with different levels of modelling complexity. The developed experimental and numerical tools support model validation, parametric analyses, and experimental testing, to gain further insights into the wheel-shoe contact interaction.

download the full-text of this paper (PDF, 10 pages, 631 Kb)

go to the previous paper
go to the next paper
return to the table of contents
return to the volume description