Effects of Pad Surface Topography on Disc Brake Squeal

2012 ◽  
Vol 165 ◽  
pp. 58-62 ◽  
Author(s):  
Ahmad Razimi Mat Lazim ◽  
Mohd Kameil Abdul Hamid ◽  
Abd Rahim Abu Bakar
Keyword(s):  
Surface Topography ◽  
Optical Microscope ◽  
Frequency Noise ◽  
Brake Pad ◽  
Brake Squeal ◽  
Stick Slip ◽  
Disc Brakes ◽  
Brake Dynamometer ◽  
Warranty Claims ◽  
Microscopic Techniques

Brake squeal has always been a major NVH problem to many car makers due to significant number of warranty claims. Brake squeal is a high frequency noise (above 1 kHz) emanating from car disc brakes that get excited due to one or more mechanisms such as mode coupling, stick-slip, hammering and sprag-slip. This paper attempts to investigate the effects of brake pad surface topography on squeal generation. Two pairs of a non-asbestos organic (NAO) brake pad will be tested on a brake dynamometer test rig. Surface topography of the brake pad will be analyzed through microscopic techniques using energy dispersive X-ray analysis (EDX), and optical microscope.

scholarly journals Experimental Evaluation of Brake Pad Material Propensity to Stick-Slip and Groan Noise Emission

Lubricants ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 107 ◽  
Author(s):  
Alessandro Lazzari ◽  
Davide Tonazzi ◽  
Giovanni Conidi ◽  
Cristian Malmassari ◽  
Andrea Cerutti ◽  
...  
Keyword(s):  
Low Frequency ◽  
Dynamic Responses ◽  
Brake Disc ◽  
Frequency Noise ◽  
Brake Pad ◽  
Noise Emission ◽  
Stick Slip ◽  
Brake Pads ◽  
Noise Vibration ◽  
Worn Surface

Frictional and dynamic responses of brake pad materials, when sliding on brake disc counterfaces, are at the origin of noise, vibration and harshness (NVH) issues such as brake noise emissions. In more detail, groan is a low frequency noise emission often associated to the stick-slip frictional response of the brake system. The instability of such contact is the result of the coupling between the system dynamics and the frictional response of the materials in contact. In this work, an experimental approach is proposed for measuring the frictional response and the propensity to generate stick-slip of different lining materials, coming from commercial brake pads, when sliding on a worn surface of a brake disc, under the same controlled boundary conditions. The proposed methodology allowed for comparing the propensity of the tested pad materials to stick-slip vibrations, which is in agreement with feedback from automotive industry on groan emission.

Tribological and dynamical analysis of a brake pad with multiple blocks for a high-speed train

2019 ◽  
Vol 234 (11) ◽  
pp. 1771-1788
Author(s):  
YK Wu ◽  
JL Mo ◽  
B Tang ◽  
JW Xu ◽  
B Huang ◽  
...  
Keyword(s):  
High Speed ◽  
Wear Behavior ◽  
Dynamical Analysis ◽  
Brake Disc ◽  
Brake Pad ◽  
High Speed Train ◽  
Brake Squeal ◽  
Element Analysis ◽  
Single Block ◽  
Middle Ring

In this research, the tribological and dynamical characteristics of a brake pad with multiple blocks are investigated using experimental and numerical methods. A dynamometer with a multiblock brake pad configuration on a brake disc is developed and a series of drag-type tests are conducted to study the brake squeal and wear behavior of a high-speed train brake system. Finite element analysis is performed to derive physical explanations for the observed experimental phenomena. The experimental and numerical results show that the rotational speed and braking force have important influences on the brake squeal; the trends of the multiblock and single-block systems are different. In the multiblock brake pad, the different blocks exhibit significantly different magnitudes of contact stresses and vibration accelerations. The blocks located in the inner and outer rings have higher vibration acceleration amplitudes and stronger vibration energies than the blocks located in the middle ring.

The effects of grooved rubber blocks on stick–slip and wear behaviours

2018 ◽  
Vol 233 (11) ◽  
pp. 2939-2954 ◽  
Author(s):  
Xiao Cui Wang ◽  
Ji Liang Mo ◽  
Huajiang Ouyang ◽  
Xiao Dong Lu ◽  
Bo Huang ◽  
...  
Keyword(s):  
Relative Velocity ◽  
Surface Modifications ◽  
Experimental Results ◽  
Brake Disc ◽  
Experimental Setup ◽  
Brake Pad ◽  
Stick Slip ◽  
Elastic Rubber ◽  
Disc Configuration ◽  
Rubber Block

This work presents an experimental and theoretical combined study of the effects of the elastic rubber blocks with different surface modifications on the friction-induced stick–slip oscillation and wear of a brake pad sample in sliding contact with an automobile brake disc. The experiments are conducted on the customized experimental setup in a pad-on-disc configuration. The experimental results show that (1) the friction system with the plain rubber block still exhibits visible stick–slip oscillation, but the intensity of the stick–slip oscillation is reduced to a certain degree compared with the Original friction system (without rubber block); (2) the grooved rubber blocks display a better ability to reduce the stick–slip oscillation compared with the plain rubber block; (3) the rubber blocks with a vertical groove (perpendicular to the relative velocity) or a horizontal groove (parallel to the relative velocity) or a diagonal groove (45° inclined to the relative velocity) on their surfaces can suppress the stick–slip oscillation more effectively with various degrees of success. The experimental results also reveal the varying effects of the different rubber blocks on wear. To explain the experimental phenomenon reasonably, a theoretical analysis is conducted to investigate the effects of different rubber blocks on both stick–slip oscillation and wear using ABAQUS. Furthermore, the analysis of the contact pressure on the pad interfaces and the deformation of the rubber blocks are studied to provide a possible explanation of the experimental results.

Effect of Bonding Pressure on Transient Liquid Phase Bonding Joint Microstructure and Properties of T91/12Cr2MoWVTiB

2010 ◽  
Vol 97-101 ◽  
pp. 107-110 ◽  
Author(s):  
Si Jie Chen ◽  
Si Jing Guo ◽  
Feng Liang
Keyword(s):  
Liquid Phase ◽  
Transient Liquid Phase ◽  
Optical Microscope ◽  
Isothermal Solidification ◽  
Transient Liquid Phase Bonding ◽  
Bonded Joints ◽  
Electron Microscopic ◽  
Bonding Pressure ◽  
Scanning Electron Microscopic ◽  
Microscopic Techniques

T91/12Cr2MoWVTiB was bonded by transient liquid phase bonding process with different pressures, one commercial FeNiCrSiB was used as the interlayer. The microstructure and components distribution of the bonded joints were examined by optical microscope and scanning electron microscopic techniques. Furthermore, the properties of the joints were also tested. The results indicate that with the increase of the pressure – from 2 MPa to 6 MPa – the microstructures and mechanical properties were improved, and more similar to those base alloys. A theoretical study also revealed that the isothermal solidification complication time can be shorter, because the maximum liquid width was reduced with the existence of pressure.

Influence of Silica Sand Particles on Disc Brake Squeal Noise

2013 ◽  
Vol 471 ◽  
pp. 81-85 ◽  
Author(s):  
Ahmad Razimi Mat Lazim ◽  
Abd Rahim Abu Bakar ◽  
Mohd Kameil Abdul Hamid ◽  
Izzat Mohd Asri
Keyword(s):  
Surface Condition ◽  
Surface Characteristics ◽  
Silica Sand ◽  
Brake Pad ◽  
Brake Squeal ◽  
The Road ◽  
Film Distribution ◽  
Before And After ◽  
Sand Particles ◽  
On The Road

Researchers in recent years begin to explore on tribological behavior of automotive brake squeal phenomena which covers the morphology, chemical composition, friction and wear, phase composition and third body or friction film distribution. However less effort has been made to study the tribological on the influence of small particles on brake squeal. During braking condition, both rotor and pads are exposed to road environmental particle which may affect pads surface condition. In order to assess the influence of this particle on brake squeal a series of squeal tests were performed. Silica sand grit particles with a size range between 400 to 200 μm which most available on the road surface were used in this experiment. Brake pad and disc surface characteristics were analyzed before and after squealing condition using Scanning Electron Microscope (SEM) and Energy dispersive X-ray analysis (EDX). The result shows that the silica sand particles had influence the squeal and surface behavior of the brake pad.

Braking Impact of Normal Dither Signals

2005 ◽  
Author(s):  
Jeff Badertscher ◽  
Kenneth A. Cunefare
Keyword(s):  
Contact Stiffness ◽  
Frequency Control ◽  
Primary Resonance ◽  
Theoretical Models ◽  
Friction Reduction ◽  
Hertzian Contact ◽  
Brake Squeal ◽  
Stick Slip ◽  
Friction Oscillator ◽  
Braking Torque

Dither control is a method of introducing high frequency control efforts into a system to suppress a lower frequency disturbance. One application of dither control is the suppression of automotive brake squeal. Brake squeal is a problem that has plagued the automotive industry for years. Placing a piezoceramic stack actuator in the piston of a floating caliper brake creates an experimental normal dither system. Many theoretical models indicate a reduction in the braking torque due to the normal dither signal. Using a Hertzian contact stiffness model the loss in friction is due to lowering the average normal force. There are also theories that the dither signal eliminates the ‘stick-slip’ oscillation causing an effective decrease in the friction force. Yet another theory indicates that the effective contact area is reduced, lowering the mean coefficient of friction. A particular approach considering a single degree of freedom friction oscillator predicts a maximum friction reduction of 10%, occurring at the primary resonance of the system. This paper will concentrate on validating this claim by experimentally determining braking torque reduction for a variety of dither control signals. Several dither control frequencies were chosen at system resonances, while others were chosen at frequencies most likely to provide control of the system. These frequencies were chosen based on previous squeal suppression research. The results indicate that dither control frequencies at system resonances have a greater impact on the braking system’s performance. In general, dither control reduces braking torque by no more than 2%.

Corrosion of Glazes Coated with Functional Films in Detergent Solutions

2006 ◽  
Vol 45 ◽  
pp. 156-161 ◽  
Author(s):  
Minna Piispanen ◽  
Linda Fröberg ◽  
Thomas Kronberg ◽  
Sami Areva ◽  
Leena Hupa
Keyword(s):  
Surface Roughness ◽  
Everyday Life ◽  
Surface Topography ◽  
Chemical Resistance ◽  
Sol Gel ◽  
Optical Microscope ◽  
Alkaline Environments ◽  
Zirconia Films ◽  
Excellent Chemical ◽  
Detergent Solutions

The goal of this work was to establish the compatibility of mat glazes with functional films known to render the surfaces with self-cleaning or easy-to-clean properties. Glazes with wollastonite, pseudowollastonite, diopside and zircon as the main crystalline phases in the surfaces were coated with fluoropolymer as well as ceramic, sol-gel derived titania and zirconia films. The glazes were soaked in typical detergent solutions used in everyday life up to four days. The surface roughness was measured with confocal optical microscope and the surface was imaged and analyzed with SEM/EDXA. When applied on wollastonite and pseudowollastonite containing glazes the functional films readily reacted in water solutions by pitting of the surface in the vicinity of the crystals. The ceramic titania and zirconia films showed better chemical resistance on wollastonite –free glazes, while the fluoropolymer film corroded in the most alkaline environments. The results indicate that functional films could be used also on rough surfaces without markedly affecting the surface topography. However, the films should be applied only on glazes with an excellent chemical resistance.

scholarly journals Influence of dynamic brake pad properties on automotive disk brake squeal

PAMM ◽  
2011 ◽  
Vol 11 (1) ◽  
pp. 345-346 ◽  
Author(s):  
Sylwia Hornig ◽  
Nils Gräbner ◽  
Utz von Wagner
Keyword(s):  
Brake Pad ◽  
Brake Squeal ◽  
Disk Brake

scholarly journals 210 Influences of Brake Pad Thickness on Disk Brake Squeal

2009 ◽  
Vol 2009 (0) ◽  
pp. _210-1_-_210-6_
Author(s):  
Kyoko KOSAKA ◽  
Yukio NISHIZAWA ◽  
Yutaka KURITA ◽  
Yasunori OURA
Keyword(s):  
Brake Pad ◽  
Brake Squeal ◽  
Disk Brake

scholarly journals INFLUENCE OF VANES SHAPE ON THE HIGH FREQUENCY NOISE OF VENTILATED DISC BRAKES IN HEAVY VEHICLES

2017 ◽  
Vol 43 (3) ◽  
pp. 1-9
Author(s):  
Nadica Stojanović ◽  
◽  
Jasna Glišović ◽  
Jovanka Lukić ◽  
Ivan Grujić
Keyword(s):  
High Frequency ◽  
Frequency Noise ◽  
Heavy Vehicles ◽  
High Frequency Noise ◽  
Disc Brakes
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