Vibration Analysis of a Backing Plate in Drum Brake Noise Generation and Brake Noise Suppression

This paper deals with the analysis of vibration mode of a drum-type rear brake and a countermeasure to squeal noise generation. Attention was paid to backing plate vibration since the vibration node of backing plate was usually difficult to recognize distinctly when squeal noise occurred in a bench test. In contrast' in a car noise test, the vibration node usually appeared distinctly. For determining a squeal noise characteristic, we carried out FEM vibration analysis and experimental modal analysis of the backing plate and obtained the characteristic frequency and vibration mode, and then identified the bending mode of 6 nodes located at the same position as that in the car noise test. A countermeasure to reduce the vibration was taken by stiffening the circumferential edge of a backing plate. Decrease in accelerance was identified by FEM frequency response analysis and impact testing. The effect of the countermeasure was confirmed in the car noise test.