Analysis Of Key Factors Of Brake Screaming Noise In Ventilated Disc Brake

After a long period of development, the automotive disc brakes have become increasingly adapt to the modern automobile industry. The current mainstream car brakes are ventilated disc brakes, which have a simple structure and easy to repair, high thermal stability and water stability, braking torque increase ease, little impact on the direction of braking and many other advantages, but there are some problems such as braking torque insufficient,brake noise serious and cost control difficulty.In this paper, the three-dimensional solid model was built in order to study ventilated disc brake squeal, using modal analysis and harmonic response analysis method to study the impact of three kinds of factors that associating with the braking system on the break squeal noise, we get the following conclusions:(1) The unstable modes corresponding to the brake squeal noise is formed by bending mode of brake pads and shear wave mode of the brake disk coupling,and the frequency scope belongs to the high-frequency squeal noise.(2) Through free modal analysis of parts, we get the inherent frequency and find that the change rate of the frequency and amplitude exists the most significant jump phenomenon when it reaches coupling frequency.(3) To the brake system under harmonic loads, the size of the vibration amplitude is proportional to the positive pressure, which is nothing to do with the vibration frequency.(4) Increase system damping is an effective way to reduce or eliminate squeal noise, damping has different effects on the change rate of amplitude and frequency, its ability to reduce the amplitude is decreased, while the ability to reduce the frequency is enhanced with the increasing damping values.(5) The change of harmonic excitation phase angle can cause an overall reduction in the resonance frequency, using appropriate excitation frequency and phase is helpful to achieve active control of brake squeal noise when multiple harmonic load interaction.By modal analysis and harmonic response analysis, we found some of thefactors affecting the specific mode of action of screaming noise, combined with the findings indicate the main research direction of screaming noise control,which has reference value to explore the generation principle of squeal noise and further optimization design of disc brake.