Selected natural frequencies of brake components are specified as quality features in the production drawings and are used for series monitoring. The manufacturer must prove and document that the components (e.g. brake discs or brake pads) correspond to the given specification. The monitoring is usually carried out as a 100% control, but can also be checked in random samples depending on agreement.
The natural frequencies are already agreed and defined by the manufacturer in the development phase to match the overall design of a vehicle platform. The aim is to prevent resonance during braking and to minimize noise. The specified natural frequencies are monitored during the manufacturing process as a quality feature using acoustic resonance analysis (or FRF).