Analysis for Reducing Low Frequency Squeal of Disc Brake

Author(s):  
Yoichi Kumemura ◽  
Yoshikazu Gamo ◽  
Kimiyasu Kono ◽  
Satoru Suga
Keyword(s):  
Author(s):  
Hartmut Hetzler ◽  
Wolfgang Seemann

Today, low frequency disc-brake noises are commonly explained as self-sustained stick-slip oscillations. Although, at a first glance this explanation seems reasonable, there are indices that cast doubt on it. For instance, the basic frequency of the observed oscillations does not scale with the disc-speed as it is with stick-slip oscillations and the classical model does not explain the observed ending of the vibrations beyond a certain speed. Indeed, our experimental studies on groaning noises reveal two different vibration patterns: stick-slip vibrations at almost vanishing relative speed and a second, differing vibration pattern at low to moderate relative speeds. Yet, these two patterns produce a very similar acoustic impression. While the experiment provides a vast amount of data, the dimension and structure of the underlying oscillation is not known a priori – hence, constructing phenomenological minimal models usually must rely on assumptions, e.g. about the number of DOF, etc. Due to noise and complexity, the measured raw data did only allow for a first straight forward insight, rendering further analysis necessary. Hence, time-delay embedding methods together with a principle component analysis were used to reconstruct a pseudo-phase space together with the embedded attractor to analyse for the system's dimension and to separate signal from noise.


PAMM ◽  
2005 ◽  
Vol 5 (1) ◽  
pp. 95-96 ◽  
Author(s):  
H. Hetzler ◽  
W. Seemann
Keyword(s):  

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.


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

1997 ◽  
Author(s):  
Toru Matsushima ◽  
Masaaki Nishiwaki ◽  
Hiroyuki Masumo ◽  
Satoshi Ito

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