Materials with high damping values are favored in the development of noiseless brake systems, as they are able to dissipate more vibrational energy and hence emit less sound. This paper describes investigations of material damping based on modal parameter estimation. Modal damping analysis is carried out for brake discs and specimen cut from the original brake discs in order to evaluate whether modal damping correlates for parts made out of the same material but vibrating in different mode shapes. It shall be analyzed, whether the modal damping of cast iron specimens can be used in order to define the material’s damping behavior which then would be applicable to vibrations of any geometry made out of the investigated material. The experiments are performed on the test bench originally developed by Rausch et al. as described in paper EB2017-VDT-022 (2). Further research is conducted in order to gain deeper understanding of the modal parameter estimation of brake discs, which potentially possess interfering eigenfrequencies. However, combined analysis of simulative and experimental data prove, that modal damping parameters can be defined with high accuracy using a single degree of freedom algorithm for parameter estimation. This finding allows for the comparison of the measured modal responses of specimens and brake discs.
Philipp Diel, M Plan GmbH, Germany; Steffen Horwath, Christian Rausch, , Hans-Peter Klatt, Hans-Peter Klatt engineering dynamics, Germany