• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2006.11a
• /
• pp.266-269
• /
• 2006

Tire is in charge of a lot of function, which is supporting vehicle load, transferring traction and. brake, absorbing impact by road etc. As the silence of vehicle increase more important, the importance of tire noise is more raised. In recent, the study on reduction of tire noise is generally processed. Tire noise is divided in structure home noise and all borne noise. Tire tread properties have a lot of multiplicity. Rubber properties are caused by changing or tread hardness. That change Elastic Modulus and Loss Modulus, which is related by tire noise. In the study, we found that road noise is affected by tread hardness

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2006.11a
• /
• pp.690-693
• /
• 2006

As the silence of vehicle is more important, noise reduction of tire is more required. Noise of tire is divided into structure home noise and air borne noise. Tire tread has the property such as Hardness. Pattern Noise is caused by changing of tread hardness. This property has influence on the mechanisms which are Block Impact & Stick-slip sound. In the study, we found that the effect of Hardness is related to more Stick-Slip than Impact.

• Proceedings of the KSR Conference
• /
• 2008.11b
• /
• pp.1642-1645
• /
• 2008

It is said that the effect in wheels of freight car varies with the type of freight, the condition of operation, the braking device, and the type of bogie. The hardness of open wagon, gondola car, propylene car, covered freight car, container car and hopper car has been measured according to the mileage through this research. As a result, the wheel with more mileages after shaving off the wheel tread has a higher hardness than the others in the case of same type of car.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2009.04a
• /
• pp.203-206
• /
• 2009

Articulation Index(AI) is the one of the evaluating methods for the interior sound of the automobiles. The AI measures the articulation level of the sound in the vehicle cabin as passengers talk to another. In this study, the effects of AI were investigated according to the various structures of tire. As the structures of tire were changed, the road noise of the vehicle tire was measured using objective measurement. From this measurement data, the AI was calculated. The AI of front is larger than that of rear. Increasing the tread hardness of tire or decreasing the apex height the AI is improved.

• The Korean Journal of Ecology
• /
• v.17 no.2
• /
• pp.149-157
• /
• 1994

To investigate the causes of distribution of Kummerowia striata (Thunb.) Schindl. mostly restricted on the roadside and reclaimed land, plant growth was analyzed under different of tread-pressures: $P_1$(10 times/day, $16.34Kg/cm^2$), $P_2$(20 times/day, $31.52 Kg/cm^2$), $P_3$(30 times/day, $40.79 kg/cm^2$) and the control $P_c$(0 times/day, $3.73 Kg/cm^2$). The matter production in the $P_1$decreased compared with that in the $P_c$, and those in the $P_2$and $P_3$ continuously decreased so that its length growth gradually decreased and, in particular, the growth of leaves and nodule was suppressed. The number of leaves and roots tended to increase in the $P_2$and $P_3$. The water contents of roots following the increase of tread-pressure increased continuously. Following the increase of tread-pressure, T/R ratio and C/F ratio tended to increase. Kummerowia striata showed the highest growth in the $P_c$ and showed 26% relative growth in the $P_1$compared with that in the $P_c$. This plant showed 8% relative growth in the $P_3$, which is excess to the tread-pressure $21Kg/cm^2$, the limit of growth in the plant. Because this plant grew continuously in the P$_3$, the tread-pressure is regarded as an important factor affecting the roadside distribution of this plant.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2010.05a
• /
• pp.694-695
• /
• 2010

• Elastomers and Composites
• /
• v.48 no.3
• /
• pp.201-208
• /
• 2013

In this study, effect of different amounts of sulfur and vulcanization accelerators in the acrylonitrile styrene-butadiene rubber (AN-SBR)/silica compounds on the properties of tire tread compound were studied. As a result, cure rate and degree of cross-linking of the compounds were increased due to enhanced cross-linking reactivity by the increased amounts of sulfur and vulcanization accelerators. Also, abrasion resistance and the mechanical properties such as hardness and modulus of the compounds were improved by enhanced degree of cross-linking of the compounds. For the dynamic properties, tan ${\delta}$ value at $0^{\circ}C$ was increased due to the increase of glass transition temperature ($T_g$) by enhanced degree of cross-linking of the compound, and tan ${\delta}$ value at $60^{\circ}C$ was decreased. Initial cure time ($t_1$) showed the linear relationship with tan ${\delta}$ value at $60^{\circ}C$. This result is attributed that reduced initial cure time ($t_1$) of compounds by applying increased amount of curatives can form cross-linking in early stage of vulcanization that may suppress development of filler network. This result is verified by observation on the surface of annealed compounds using AFM (atomic force microscopy). Consequently, decreased initial cure time is considered a very important parameter to reduce tan ${\delta}$ at $60^{\circ}C$ through reduced re-agglomeration of silica particles.

• Journal of the Korean Society for Precision Engineering
• /
• v.31 no.9
• /
• pp.783-790
• /
• 2014

Railway wheels and axles are the most critical parts of the railway rolling stock. The wheel carry axle loads and guide the vehicles on the track. Therefore, the contact surface of wheel are subjected to wear and fatigue process. The wheel damage can be divided into three types; wear, contact fatigue failure and thermal crack due to braking. Therefore, in the contact surface between the wheel and the rail, the materials are heat treated to have a specific hardness. The manufacturing quality of the wheel have a considerable influence on the formation of tread wear and damage. Also, the residual stress on wheel is formed during the manufacturing process is one of the main sources of the damage. In this paper, the mechanical characteristic and the residual stress according to wheel material have been evaluated by applying finite element analysis and conducting mechanical tests.

• Elastomers and Composites
• /
• v.55 no.3
• /
• pp.215-221
• /
• 2020

Silica/SBR (styrene-butadiene rubber) compounds are the primary constituents of tire treads. Furthermore, the excellent dynamic viscoelastic properties of silica lead to good fuel efficiencies. However, the silanol group on the surface of silica does not mix well with non-polar rubber because of its polarity. This incompatibility causes aggregation due to the occurrence of hydrogen bonding between the hydroxyl groups, thereby reducing the dispersibility of silica. Recently, the wet master batch (WMB) process has been applied to overcome these disadvantages, and research on silica dispersants that can be used in the WMB process has been increasing. In this study, we prepared silica/SBR compounds by using three types of eco-friendly cellulose-based dispersants in the WMB process, namely: cellulose-, sodium carboxymethyl cellulose, and nanocellulose-based dispersants. Subsequently, we compared the vulcanization characteristics, viscoelastic properties, and mechanical properties of the compounds. The silica dispersibility in the rubber compounds was improved with the addition of the nano-cellulose dispersant, resulting in the enhancement of the workability, hardness, tensile strength, and wear resistance of the SBR compound.

• Applied Chemistry for Engineering
• /
• v.2 no.4
• /
• pp.356-362
• /
• 1991

The physico-mechanical properties of NR/BR blend were measured, and the results were interpreted in terms of the crosslink density with cure system. The cure rate, maximum torque and crosslink density increase with the content and ratio of curative for cure system. Hardness, 300 % tensile modulus, rebound and wear resistance increase with crosslink density of the vulcanizate but heat build-up and tan $\delta$ at $60^{\circ}C$ decrease. It is expected that semi-EV(efficient vulcanization) cure system is appropriate for application in tire tread of truck/bus in which load bearing property is impotant.