• Elastomers and Composites
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• v.56 no.4
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• pp.243-249
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• 2021

The demand for truck bus radial (TBR) tires with enhanced fuel efficiency and wear resistance have grown in recent years. In addition, as the issue of particulate matter and air pollution increases, efforts are being made to reduce the generation of particulate matter. In this study, we investigated the effect of varying the content of butadiene rubber (BR) on the properties of the rubber compounds and the amount of particulate matter in the TBR tire tread compound. Furthermore, we utilized carbon black in the NR/BR blend compounds owing to its excellent compatibility, and we used silica in the ENR-25/BR blend compounds because it can interact chemically with epoxide groups. The NR/BR blend compounds and the ENR-25/BR blend compounds were evaluated by varying their BR content between 20 phr and 30 phr. The results showed that the ENR-25/BR blend compounds had superior wear resistance than the NR/BR blend compounds. This was caused by the interaction between silica and ENR. In addition, it was confirmed that the increased wear resistance as the BR content increased. Furthermore, compared to the NR/BR blend compounds, ENR-25/BR blend compounds exhibited a lower tan 𝛿 value at 60℃ because silica was used as filler. This indicates a higher fuel efficiency. The measurement results for wear particulate matter showed that as increasing the BR content resulted in generation of less wear particulate matter. This was caused by the increased wear resistance. Moreover, the ENR-25/BR blend compounds with excellent filler-rubber interaction exhibited lower quantities of generated wear particulate matters as compared to the NR/BR blend compounds.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.1
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• pp.106-111
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• 2012

Recently the usage of bicycle has increased steeply in Korea owing to traffic culture of well- being. In a car to bicycle accident investigation, the throw distance of bicycle is very important factor for reconstructing of the accident. The variables that influence on the throw distance of bicycle can be classified into the factors of vehicle and bicycle. Simulations and collision tests in actual car to bicycle accident were executed for obtaining throw distance of bicycle. The simulations were done by PC-$CRASH^{TM}$ and for actual crash tests sand bags were used for the behavior of bicyclist instead of dummy. Factors considered were vehicle velocity and the moving angles of bicycle, also the types of bicycle and vehicle were fairy cycle and automobile, respectively. From the results, the throw distances of a head-on tire collision of $0^{\circ}$ direction was longer than that of tire crash test of $45^{\circ}$ direction, and the throw distances of a head -on frame crash test of $90^{\circ}$ direction was longer than that of frame crash test of $45^{\circ}$ direction. In addition restitution coefficient between vehicle and bicycle was estimated as about 0.1 with based on actual crash tests. Finally the increaser vehicle velocity the longer the throw distances of bicycle, and the results of simulation were relatively good agreement to the experimental results.

• Journal of Practical Engineering Education
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• v.15 no.1
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• pp.53-61
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• 2023

The biggest core task in the new modern automobile industry lies in the development of eco-friendly vehicles with the goal of 0% emissions by the EU by 2035. Accordingly, in an era where the industry is rapidly changing with electric vehicles, education and training on EV electric vehicles are urgently needed. In this study, by developing a core EV powertrain system simulator excluding the chassis platform (body, tire, etc.) used identically to existing internal combustion locomotives, Understand the EV powertrain system, including mechanical engineering, electrical engineering, and electronic engineering applications. Through this course, we intend to use it as a medium to develop engineering and convergence development capabilities.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.10
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• pp.41-50
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• 1998

In this study, to investigate a characteristics of slip ratio control of H.C.U for ABS, half car model tester were developed and a new H.C.U. was compactly designed comparing to the commercical H.C.U. for ABS. In half car model tester, variable inertia wheel has been used to load the car weights and braking forces according to the road surface conditions which were realized by pneumatic cylinder. And solenoid valves using P.W.M. (Pulse Width Modulation) method were installed in the new H.C.U The slip ratio characteristics of tire had been measured using half car model tester and the results were used in the control simulation for a new H.C.U.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.10a
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• pp.124-127
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• 2007

In this study, we focused on investigation of governing parameters affected on the fatigue properties in the hyper-eutectoid steel wires used for TBR tires. Steel wires are fabricated under different drawing strain from 3.36 to 3.80. Their diameters are 0.21 mm and 0.185mm, respectively. The fatigue properties was measured by hunter rotating beam tester, specially designed thin-sized steel wires. The results showed that the fatigue properites of steel wire, marked as A-1, were greater than the others, due to the low value of residual stress. In order to elucidate the variations of fatigue properties, the microstructure, surface defect and residual stress were observed and measured by useful analysis technique, such as TEM, 3D profiler and FIB.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.05a
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• pp.454-457
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• 2008

Effects of patenting temperature on bending fatigue resistance of pearlitic steel filaments were investigated experimentally. The fatigue resistance of steel filaments was carried out by using hunter machine, specially designed for ultra fine-sized steel wires, in the controlled conditions. The transmission electron microscopy (TEM) was used for observing the overall microstructure. It revealed that the fatigue resistance as well as tensile strength increased together with increase of patenting temperature from 510 to $600^{\circ}C$, while the endurance ratio ($\sigma_e/\sigma_{TS}$) of filaments decreased. It is believed that this variation of mechanical properties with change of patenting temperature should be strongly influenced by the change of microstructure. The bending fatigue properties of steel filaments were discussed based on microstructural parameters.

• International Journal of Automotive Technology
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• v.4 no.4
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• pp.181-191
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• 2003

Since the nonlinearity and uncertainties which inherently exist in vehicle system need to be considered in active suspension control law design, this paper proposes a new control strategy for active vehicle suspension systems by using a combined control scheme, i.e., respectively using a genetic algorithm (GA) based self-tuning PID controller and a fuzzy logic controller in two loops. In the control scheme, the PID controller is used to minimize vehicle body vertical acceleration, the fuzzy logic controller is to minimize pitch acceleration and meanwhile to attenuate vehicle body vertical acceleration further by tuning weighting factors. In order to improve the adaptability to the changes of plant parameters, based on the defined objectives, a genetic algorithm is introduced to tune the parameters of PID controller, the scaling factors, the gain values and the membership functions of fuzzy logic controller on-line. Taking a four degree-of-freedom nonlinear vehicle model as example, the proposed control scheme is applied and the simulations are carried out in different road disturbance input conditions. Simulation results show that the present control scheme is very effective in reducing peak values of vehicle body accelerations, especially within the most sensitive frequency range of human response, and in attenuating the excessive dynamic tire load to enhance road holding performance. The stability and adaptability are also showed even when the system is subject to severe road conditions, such as a pothole, an obstacle or a step input. Compared with conventional passive suspensions and the active vehicle suspension systems by using, e.g., linear fuzzy logic control, the combined PID and fuzzy control without parameters self-tuning, the new proposed control system with GA-based self-learning ability can improve vehicle ride comfort performance significantly and offer better system robustness.

• Journal of the Korean Chemical Society
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• v.61 no.6
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• pp.339-345
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• 2017

Carbonaceous adsorbent (CA-WTP) was prepared by heat treatment at $400^{\circ}C$ for 2 h in N2 atmosphere using waste tire powder (WTP). WTP and CA-WTP were first characterized by thermo-gravimetric analysis (TGA), energy dispersive X-ray spectrometer (EDS), scanning electron microscopy (SEM), specific surface area analysis (BET) and FT-IR spectroscopy. Then, they were tested as adsorbents for removal of Cd in water. CA-WTP exhibited much higher specific surface area and total pore volume than WTP itself and showed higher adsorption capacity for Cd. Equilibrium data of adsorption were analyzed using Freundlich and Langmuir isotherm models. It was seen that both Freundlich and Langmuir isotherms have correlation coefficient $R^2$ value larger than 0.95. The results of studies indicate that CA-WTP developed from WTP by heat treatment could be used as efficient adsorbent for the removal Cd from water.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.4
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• pp.199-206
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• 2006

Real time vehicle dynamics models have been developed with the subsystem synthesis method for intelligent vehicle HILS system. Three different models for solving subsystem equations are compared in order to find out the best suitable model for HILS applications. The first model is based on the generalized coordinate partitioning technique, and the second one is on the approximate function approach, and the last one is on the constraint stabilization method. To investigate the theoretical efficiency of three proposed methods, arithmetic operators used in the formulations of three models are counted. Bump run simulations with half-sine bump have also carried out with three different models to measure the actual CPU time to validate theoretical investigation.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.2
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• pp.129-143
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• 1998

The vibrations of steering wheel are required to be reduced for convenient ride quality and good controllability. This phenomenon, vibration of steering wheel, is occured by interaction with suspension system, steering system, vehicle body, engine/transmission and tire complicately. But reviewing the current research activities, most researches are performed for the vibration analysis of steering wheel with a simple model, and mot easy to be applied to the variation of each component element connected with steering system as well as that of the steering system. In this study, suspension system and steering system are modelled by the T.L.H. coordinate system which is usually used by a passenger car maker. Also, rigid body motions of engine and elastic motions of vehicle body in the previous study are considered. Derive the equation of motion in 29 d.o.f. and the vibration of steering wheel is analyzed numerically and verify the midelling of steering system by comparison with test results for real car. And then, the optimal design values of the engine mount system obtained from the previous study are applied to the verified steering system model and investigate the effects of various engine mount design values on the vibration of steering wheel.