Experimental Study of Disc In-Plane Mode which Induced Brake Squeal

Previous studies have shown that the disc vibration mode during braking noise is not always the same and there are some types of mode. Until now, disc brake noise studies are reported regarding out of plane noise primarily, and there are many noise countermeasure methods. On the other hand, there is short research history of “Inplane mode noise” which disc vibrates to circumstance direction with extension and contraction movement. Therefore, there are few studies which are explained the noise mechanism in detail in the view point of pad.

In this report, we discuss energy which flows into pad surface at inplane noise braking and focused friction force variation by the surface pressure change especially. The inflow energy was calculated by the pad’s displacement of disc rotating direction(ΔX) and pad thickness variation(Δh) which is acquired by 3D scanning laser Doppler measurement system. This technique was made in reference to the past research. (Y.Ichiba&Y.Nagasawa SAE Technical Paper 930802(1993))