Progressive waviness distortion: A new approach of hot spotting in disc brakes
Résumé
This paper deals with the mechanisms of the appearance of hot spots in railway brake disks. From infrared measurements, a classification of hot spots is presented. The most damaging thermal gradients are identified as macroscopic hot spots uniformly distributed on the friction surface. An explanation of the origin of these macroscopic hot spots is presented based on a scenario of progressive distortion of the disk. Three major effects have to be considered: the structural response of the disk and the pads; realistic boundary conditions, both geometric and loading; and the thermoelastoplastic behavior of the material. Finite element simulations based on the proposed model agree with experimental observations.