<div class="htmlview paragraph">Eliminating brake squeal generated during brake application is an important task for the improvement of comfort in the vehicle. There has been a lot of research made on the problem of brake squeal in the past. And most of the papers presented elaborate on low frequency brake squeal (2-3kHz). However, brake squeal has often the high-frequency vibration.</div> <div class="htmlview paragraph">For this reason, we have made research into the high-frequency brake squeal (5-10kHz). Double-Pulsed Laser Holography is a useful method for visualizing small vibration of brake components during brake squeal generation. The results obtained using Holographic Interferometry show the rotaing disc vibrates in the bending mode with diametral nodes.</div> <div class="htmlview paragraph">Consequently, we think that the modification of brake disc can eliminate brake squeal, which is caused by self-excited vibration. Then we have calculated natural frequency and its vibration mode of a circular-plate added mass. And we have further studied the relationship between the shape of brake disc and its vibration mode using Finite Element Method (FEM) Analysis. Based on these findings, we have derived the method of eliminating brake squeal by the modification of brake disc.</div>