Holographic analysis of vibrations on squealing drum brake systems is a useful method to localize vibration sources on drum brake components. The results described in this paper are obtained by combinations of holographic as well as classical vibration measurements.
This report describes experiments and illustrates how results in preventing brake squeal can be obtained, and used as a logical basis for the efficiency of this method.
As a consequence easier principles for suppression of brake noise can be developed.
Experiments carried out on three different types of rear brake systems show, that the main part of noise (1 to 2 kHz) is transmitted by the backing plate. Improved constructions without any tendency to squeal are demonstrated.
A main result of this new testing method is that the observations and experiments carried out are of a general nature and so they are easily transferable to other brake noise problems on drum brake systems.