First Order Analysis of Low Frequency Disk Brake Squeal

Author(s):  
Yoshitomo Denou ◽  
Masaaki Nishiwaki
2012 ◽  
Vol 134 (6) ◽  
Author(s):  
Toru Matsushima ◽  
Kazuhiro Izui ◽  
Shinji Nishiwaki

Minimizing brake squeal is one of the most important issues in the development of high performance braking systems. Furthermore, brake squeal occurs due to the changes in unpredictable factors such as the friction coefficient, contact stiffness, and pressure distribution along the contact surfaces of the brake disk and brake pads. This paper proposes a conceptual design method for disk brake systems that specifically aims to reduce the occurrence of low frequency brake squeal at frequencies below 5 kHz by appropriately modifying the shapes of brake system components to obtain designs that are robust against changes in the above unpredictable factors. A design example is provided and the validity of the obtained optimal solutions is then verified through real-world experiments. The proposed optimization method can provide useful design information at the conceptual design stage during the development of robust disk brake systems that maximize the performance while minimizing the occurrence of brake squeal despite the presence of unpredictable usage factors.


2004 ◽  
Author(s):  
Yasuaki Tsurumi ◽  
Hidekazu Nishigaki ◽  
Toshiaki Nakagawa ◽  
Tatsuyuki Amago ◽  
Katsuya Furusu ◽  
...  

1996 ◽  
Author(s):  
Ichiro Kido ◽  
Tuyoshi Kurahachi ◽  
Makoto Asai

Author(s):  
Nils Gräbner ◽  
Volker Mehrmann ◽  
Sarosh Quraishi ◽  
Christian Schröder ◽  
Utz von Wagner

2012 ◽  
Vol 107 (4) ◽  
pp. 1241-1246 ◽  
Author(s):  
Gary Marsat ◽  
Leonard Maler

To interact with the environment efficiently, the nervous system must generate expectations about redundant sensory signals and detect unexpected ones. Neural circuits can, for example, compare a prediction of the sensory signal that was generated by the nervous system with the incoming sensory input, to generate a response selective to novel stimuli. In the first-order electrosensory neurons of a gymnotiform electric fish, a negative image of low-frequency redundant communication signals is subtracted from the neural response via feedback, allowing unpredictable signals to be extracted. Here we show that the cancelling feedback not only suppresses the predictable signal but also actively enhances the response to the unpredictable communication signal. A transient mismatch between the predictive feedback and incoming sensory input causes both to be positive: the soma is suddenly depolarized by the unpredictable input, whereas the neuron's apical dendrites remain depolarized by the lagging cancelling feedback. The apical dendrites allow the backpropagation of somatic spikes. We show that backpropagation is enhanced when the dendrites are depolarized, causing the unpredictable excitatory input to evoke spike bursts. As a consequence, the feedback driven by a predictable low-frequency signal not only suppresses the response to a redundant stimulus but also induces a bursting response triggered by unpredictable communication signals.


2011 ◽  
Vol 2011 ◽  
pp. 1-14 ◽  
Author(s):  
Victor A. Sipachev

Structural studies are largely performed without taking into account vibrational effects or with incorrectly taking them into account. The paper presents a first-order perturbation theory analysis of the problem. It is shown that vibrational effects introduce errors on the order of 0.02 Å or larger (sometimes, up to 0.1-0.2 Å) into the results of diffraction measurements. Methods for calculating the mean rotational constants, mean-square vibrational amplitudes, vibrational corrections to internuclear distances, and asymmetry parameters are described. Problems related to low-frequency motions, including torsional motions that transform into free rotation at low excitation levels, are discussed. The algorithms described are implemented in the program available from the author (free).


2007 ◽  
Vol 302 (3) ◽  
pp. 527-539 ◽  
Author(s):  
Utz von Wagner ◽  
Daniel Hochlenert ◽  
Peter Hagedorn

1994 ◽  
Vol 48 (6) ◽  
pp. 733-736 ◽  
Author(s):  
N. T. McDevitt ◽  
J. S. Zabinski ◽  
M. S. Donley ◽  
J. E. Bultman

Crystalline disorder in thin films plays an important role in determining their properties. Disorder in the crystal structure of MoS2 films prepared by magnetron sputtering and pulsed laser deposition was evaluated with the use of Raman spectroscopy. The peak positions and bandwidths of the first-order Raman bands, in the region 100 to 500 cm−1, were used as a measure of crystalline order. In addition, a low-frequency feature was observed at 223 cm−1 that is not part of the normal first-order spectrum of a fully crystalline specimen. Data presented here demonstrate that this band is characteristic of crystalline disorder, and its intensity depends on the annealing history of the film. This behavior seems to be analogous to the disorder found in graphite thin films.


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