The purpose of this research is to reduce the weight of the brake system of vehicles and to increase braking performance and its durability and to shorten the stopping distance. The plans for light-weight vehicles are to develop light weight material itself which possesses superior properties and another way is to improve the manufacturing method of materials which have the better mechanical properties. And the materials used for this are aluminum alloy, magnesium alloy, titan alloy, steel, other metals, plastic, ceramic materials etc. In this research, aluminum is used for the main body of the break to reduce the weight of the brake and cast iron(SCM4), stainless steel(SUS304) and titan alloy(Ti Gr2) are used for the outer ring shape plate and assembled with bolts. Dynamometer test are braking performed on the brake disc. Based on the test results, stainless steel(SUS304) is optimized for the light-weight brake disc.

A numerical approach for ventilated disc brake with holes is carried out to investigate the effect of holes on the heat transfer characteristics. The numerical simulation code STAR-CCM+ is utilized to calculate flow and temperature fields with polyhedral meshes. The steady state results show that the holes make the flow velocity on the outer surface increasing, which induce the improvement of convective heat transfer on the outer surface. In the ventilated channel with holes, the convective heat transfer can be reduced due to the inflow of hot air through holes. In unsteady state, the disc has reached the highest temperature in 1,8s since the brake was engaged. The surface of disc without holes has maximum temperatures along the ventilated channels, while the surface temperatures of dis with holes are uniform.

In this paper, the relationship between the frequency split and the mode-coupling in the disc doublet mode, which is expressed according to the pattern of the surface of the disc, is utilized by using of 3 types(Chaos, Vent-hole, Normal). As the frequency split between the doublet mode disc that is expressed in the model through the interpretation is larger, and analogy through interpretation mode-coupling instability also lower. Vent-hole, which has a relatively large frequency split of disc doublet mode in 3 types(Chaos, Vent-hole, Normal) model, showed a large value of critical coefficient of friction in which mode-coupling instability is expressed. In addition, it was confirmed by analysis that the Vent-hole had a relatively large frequency split than the other models by analyzing the change in contact stiffness. It can be concluded that the larger the frequency split of the disc doublet mode, the lower the instability due to the mode-coupling.

The brake systems are composed of brake disc, brake pad and caliper and, these three parts play an important role for braking. In this study, heat fluid analysis is conducted for five different ventilated disc models, and two piece brake disc model separated in rotor and housing is used. In this case, each model has a different number of holes and vent shape. The basic heat flux and braking power equations are applied for the heat fluid analysis. The cooling performance with/without the braking operation is also analyzed for given five models where the material properties and boundary conditions are set to be identical. From our analysis results, it is found that the number of disc holes and ventilated pins strongly influences on the cooling performance.

The carbon brake discs were manufactured by densification the carbon fiber preform using PG-CVI technology with Propene as a carbon precursor gas and Nitrogen as a carrier gas. The densities of carbon brake discs were tested at different densification time. The results indicate that the densification rate is more rapid before 100 hrs than after 200 hrs. The CTscanning image and the SEM technology were used to observe the inner subtle structure. CT-images show the density distribution in the carbon brake disc clearly. The carbon brake disk made by PG-CVI is not very uniform. There is a density gradient in the bulk. The high-density part in the carbon brake is really located in the friction surface, especially in the part of inner circle. This density distribution is most suitable for the stator disc.