First Order Analysis of Disc Brake Noise - Relationship between Low-Frequency Disc Brake Squeal and Moan Noise -

2012 ◽  
Author(s):  
Masaaki Nishiwaki ◽  
Mikael Langthjem
2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Yidong Wu

Brake squeal is a major component of vehicle noise. To explore the mechanism of the low-frequency brake squeal, a finite element model of an automobile disc brake was established, and a complex mode numerical simulation was performed. According to the unstable modes stemming from the complex modal analysis results, the low-frequency range brake squeal can be determined. Based on an energy feed-in method, the coupling subsystems of the piston-caliper and the disc-pad were established, and a calculation formula for the feed-in energy of the dual coupling subsystem was derived. The results showed that when the feed-in energy of the dual coupling subsystem is close to zero, the complex mode cannot be excited at the corresponding frequency. In addition, the difference in feed-in energy between the two coupling subsystems is positively correlated with the probability of the brake squeal, which can be used to determine the complex mode under which the brake squeal may occur. The greater the feed-in energy of a coupling subsystem is, the more likely it is that the maximum brake vibration mode will appear at this subsystem or its adjacent parts. The increase in brake oil pressure will eliminate some lower-frequency sounds but will not change the frequency of the original low-frequency brake squeals.


Author(s):  
Xu Wang ◽  
Sabu John ◽  
He Ren

Disc brake squeal can be classified as a form of friction-induced vibration. Eliminating brake noise is a classic challenge in the automotive industry. This paper presents methods for analyzing the unstable vibration of a car disc brake. The numerical simulation has been conducted, and its results are compared with those from the experimental tests. The root causes of brake squeal noise will be identified. Potential solutions for elimination of the brake squeal noise will be proposed. Firstly, new materials and technologies for the disc brake application will be explored, secondly, it will be illustrated how to avoid the brake squeal noise problem from the brake system design. Brake disc design changes for improving cooling performance, and service solutions for brake squeal noise will be presented.


1998 ◽  
Author(s):  
Toru Matsushima ◽  
Hiroyuki Masumo ◽  
Satoshi Ito ◽  
Massaki Nishiwaki

Author(s):  
M Nishiwaki

Eliminating brake noises generated during brake application is an important issue in the improvement of comfort in vehicles. Brake noises (frequency 1–15 kHz) are often called brake squeal. On the other hand, brake noises (frequency 200–500 Hz) are often called brake groan noise. The studies on drum brake squeal, disc brake squeal and disc brake groan noise have already been presented in references (2), (3) and (4), where theoretical analyses on these brake noises were described. This paper shows that the equations of motion are represented by the same type of equations. Based on these analyses. It is clear that drum brake squeal, disc squeal and disc brake groan noise are generated by the same cause—dynamic instability of the brake system with friction force variations.


2017 ◽  
Vol 79 (7-4) ◽  
Author(s):  
S. Arvin Rao ◽  
Muhamad Anuwar Jusoh ◽  
Abd Rahim Abu Bakar ◽  
Mohd Kameil Abdul Hamid ◽  
Khidzir Zakaria

Brakes squeal has remained to be one of the major NVH challenges in brake system design and development. It has been a concern for automotive industry for decade. Brake researchers have proposed many brake squeal reduction and prevention methods in order to overcome and reduce the squeal that emanates from the brake disc systems. In this paper, the effectiveness of constrained layer dampers (CLD) in reducing disc brake squeal noise was investigated. CLD isolates the brake squeal noise through shear deformations of the viscoelastic materials. Two sets of brake tests were conducted using the brake test dynamometer with the application of CLD. Two different types of CLD were used which are three-layer constrained layer damper and four-layer constrained layer damper. Squeal tests were carried out using brake noise test rig based on the global standard procedure SAE J2521. From the test, four-layer CLD configuration works more efficient than three-layer CLD configuration. CLD made up of nitrile butadiene rubber, silicone rubber and mild steel proved to be the most effective noise insulator at hydraulic pressure range of 5 bar to 30 bar and temperature range of 50oC to 200oC with a maximum noise reduction of 11.3 dBA. Thus, CLD technique was proven to be an effective method in reducing brake squeal noise.


1989 ◽  
Vol 55 (512) ◽  
pp. 932-939 ◽  
Author(s):  
Hiroshi HARADA ◽  
Hiromasa OKAMURA ◽  
Masaaki NISHIWAKI ◽  
Takahiro IKEUCHI
Keyword(s):  

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