• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.10a
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• pp.363-368
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• 2001

Studies on brake system recently are focused on braking performance, especially the consideration on safety of braking system in an extreme situation and reduction of vibration and noise during braking operation. The thermal crack and Judder from the friction between brake disc and pad can bring the threaten of passengers' safety in the end. Braking force comes from the change of kinetic energy to friction energy. Since heat energy is developed from here, the analysis on thermal stress and thermal strain can be the good data when selecting the material of brake pad and designing heat radiation holes on the disc and it will also be the data when designing the thickness of the disc. This paper is intended to show a creative design method by suggesting the thermal analysis data through FEM study and using shape design parameters.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.1
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• pp.137-142
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• 2003

In automotive brake systems, the frictional heat generated can cause high temperature at the interface of rotor and pad which may deteriorate the material properties of the sliding parts and can result in brake fade. Conventionally, a pie-shaped 3-dimentional model is adopted to calculate temperature of ventilated disk using finite element method. To overcome the difficulties in preparing 3D finite element model and reduce the computational time required, the ventilated rotor is to be analyzed, in this study, as an axisymmetric finite element model in which, taking into considerations the effects of cooling passages, a homogenization technique is used to obtain the equivalent thermal properties and boundary conditions for the elements placed at the vent holes. Numerical tests show the proposed procedure can be successfully applied in practice, replacing 3-dimensional thermal analysis of ventilated disk.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.269-270
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• 2006

Brake noise is classified according to frequency territory: judder, groan and squeal. Squeal noise of disk brake is a noise and self excited vibration with frequency of $1{\sim}10Khz$ caused by the friction force between the disk and the pad of the automobile. Passengers in a vehicle feel uncomfortable. It causes unstable characteristic to the brake system when you try to stop the vehicle. Thus this study aims to find in which conditions the vehicles are stable during the braking hour and find ways to decrease a squeal noise and the vibration by measuring various factors including squeal noise and self excited vibration between the pad and disk brake system during the braking hour. From the result the countermeasure for a squeal noise and a vibration decrease is established. Also the analyzed data is found to be useful and can be applied to the actual brake model.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.6
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• pp.36-43
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• 2022

Automobile brake discs are a major part of automobiles that are directly related to driver safety, and prevention of judder and squall noise is very important. This phenomenon occurs for complex reasons such as the precision and assembly of the brake module, and the material of the brake disc. The purpose of this study is to analyze the effect of the grinding wheel's grain size on the grinding conditions when machining cast iron, the material of the brake disc, and to derive the optimal grinding conditions through this.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.591-592
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• 2009

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.580-581
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• 2009

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.178.2-178.2
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• 2005

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11a
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• pp.439-443
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• 2001

The steering wheel vibrations such as shimmy, brake judder and shake are affected by the vibration characters of steering and suspension. For the analysis of shimmy, nonuniformities of tire can be considered the major sources. This study investigates unbalances and uniformities of tire in which the lateral force variation is highly correlated with shimmy. The hardness of suspension bushes can be modified to change the dynamic behavior of suspension that is effective to reduce the sensitivity of shimmy.

• Journal of Power System Engineering
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• v.10 no.3
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• pp.67-72
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• 2006

The effect of manufacturing parameters on wear and improve cooling of motorcycle break system was studied using a disk-on-pad type friction tester. Such parameters conditions have an effect on the wear and improve cooling factor such as applied load, sliding speed, frictional time and number of ventilated disk hole. However, it is difficult to know the mutual relation of these factor. In this study, the wear and cooling characteristics using design of experiment containing 4 elements were investigated for an optimal condition for the best motorcycle disk break system employing Taguchi robust experimental design. From this study, the result was shown that vents have an effect on convection area improving more cooling ability and reduced wear of the disk.

• Tribology and Lubricants
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• v.16 no.2
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• pp.7-7
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• 2000

Using a coupled thermal-mechanical analysis, the dynamic distortion of the ventilated disk brakes has been presented for a high-speed train. The offset ratio between the maximum and minimum values of the thermal distortions has been analyzed as a function of a braking number. The computed FEM results show that the offset rations in radial direction are much greater than those of circumferentially distorted components. This means that the axial distortions in radial direction may dominantly produce thermally caused wears and cracks at the rubbing surfaces.