Cho H., Cho C., Kim M., Maeng J., Kim C.

Frequent braking may generate severe low frequency vibration due to non-uniform frictional contact between disk and pads. Under critical conditions, this non-uniform contact leads to locally concentrated heating, growing to hot spots in disk brake. Finally hot spot roughness induces the judder which makes the vehicle control difficult and even dangerous. Judder phenomenon for high quality of automotive brake design cannot help understanding the relationship of number of hot spots and judder vibration frequencies. This paper is to analyze the role of hot spots in judder vibration of automotive disk brake. The vibration modes of disk brake are experimentally measured and analytically examined by the finite element method. Judder vibration measurements are conducted by using chassis-dynamometer and its non-linearity is investigated by the mode analysis technique. For TEI analysis, temperature distributed on disk brake is obtained by running the software of HotspotterTM. As results, the relationship between vibration modes and non-uniform contact area can be predicted by their mode shapes; according to measurement conditions, the nonlinearity of judder vibration and influence factors are determined and its origin is discussed.