The observation is squeal noises at different frequencies on the same brake system have strong or weak dependencies on temperature. This paper attempts to explain reasons for this difference. The mode of investigation is theoretical using analytical calculations of representative geometry and empirical measuring FRF at different temperatures.
The temperature dependence appears strongest for tangential in-plane modes of vibration. Effects include modulus change with temperature and geometrical effects such as the disc hat torsional stiffness which has more impact on the tangential modes than out of plane modes. Additional effects can be seen from the friction material shear modulus and shim shear modulus, as these are in the same direction as the modes of vibration with strongest temperature dependence.
The practical application of this work is to give a quick insight into whether a noise frequency could be related to an in-plane mode of the disc.
Ishii-Dodson, Nicholas* - Roulunds Braking ApS; Thuesen, Jens - Meneta; Eggleston, David - Eurac