• Journal of Korean Society of Steel Construction
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• v.26 no.6
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• pp.559-570
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• 2014

In this study, compression and shear characteristics of laminated rubber bearings and lead rubber bearings with various parameters are investigated by using material and geometric nonlinear three-dimensional finite element analysis. Rubber coupon tests are performed to make a model of the laminated rubber bearings. In addition, the material constants of the rubber are calculated by the curve fitting process of stress-strain relationship. The finite element analysis and experimental tests of the laminate rubber bearings are used to verify the validity of the rubber material constants. It is seen that the compression behavior of the laminated rubber bearings and lead rubber bearings mainly varies depending on the first shape factors and their shear behavior significantly varies depending on the second shape factors. In addition, the horizontal stiffness and energy dissipation capacity of lead rubber bearing are increased when the diameter of a lead bar is increased.

• Elastomers and Composites
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• v.49 no.3
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• pp.220-224
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• 2014

The tire tread is contacted with road surface directly. It gives significant effect on the breaking conditions, traction, noise and so on. The tread having grooves with complex geometry is molded by shaping process. The flow behavior of tread rubber in a mold affects the quality of the tread and it leads to the running performance of automobile. In this study, the flow behavior of rubber in shaping process has been investigated by computer simulation. The objective of flow simulation is the design of tread shape based on the contact of rubber on the mold surface and flow behavior of rubber. Different sequences of contact of rubber on the mold surface and flow behavior of rubber are observed according to the shape of tread on the mold surface. It was verified that the shape of tread gives significant effect on the flow behavior of rubber. Different flow behaviors of rubber and sequential contact of rubber to the mold surface were observed according to the shape of tread on the mold surface. Therefore, we have identified that the shape of tread give a change in the flow behavior of rubber.

• Elastomers and Composites
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• v.1 no.1
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• pp.49-55
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• 1966

Based upon the results of the previous work, the experiments are concentrated on the improvement of the durability of rubber coated fabrics as a rain garment material. To obtain a much lighter and durable coated fabric, several kinds of light weight cotton prints having almost equal density in warp and fillingwise were chosen. Rubber coating on these prints was made by topping and spreading process using rubber compound of various viscosity, and the physical properties of final product were analysed and interpreted in terms of adhesion and durability. The results are as follows. 1. Any noticeable difference between two coating processes was not found in terms of physical properties. 2. Base fabrics should be dipped once into a dilute rubber compound before coating operation in order to obtain a uniform adhesion and physical properties, and the optimum range of the viscosity of dipping paste are from 100 poise to 200 poise. 3. Generally, the tearing strength of the coated fabrics is inversely proportional to the adhesion. 4. It was assumed that the increase of the water proofness after water immersion on the finished material which have dense base fabric is chiefly due to the swelling of the cellulosic fiber.

• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.5
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• pp.89-96
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• 2012

The rubber side could be contaminated using the existing pulse echo method because the ultrasonic wave was incident on the rubber side from the interior of the steel motor case, which could lead to the critical disbond defect. To develop the test method which can be replaced the existing method, the ultrasonic wave was incident on steel face of the steel/rubber adhesive test block. Rubber resonance frequencies measured from the steel/rubber adhesive test block were in good agreement with theoretically predicted rubber resonance frequencies. This paper was described about the ultrasonic resonance method to convert the rubber resonance frequency into the rubber thickness.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1998.04a
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• pp.34-39
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• 1998

In order to compute the forces which are transmitted through rubber bushings with a commercial multibody dynamic analysis (MBDA) program, a rubber bushing model is needed. The rubber bushing model of MBDA programs such as DADS or ADAMS is the Voigt model which is simply a parallel spring-viscous damper system, meaning that the damping force of the Voigt model is proportional to the frequency. However, experiments do not necessarily support this proportionality. Alternatively, the viscoelastic characteristics of rubber bushings can be better represented by the complex stiffness. The purpose of this paper is to develop a viscoelastic rubber bushing model for the MBDA programs. Firstly, a methodology is proposed to calculate the complex stiffness of rubber bushings considering static and dynamic load conditions. Secondly, a viscoelastic rubber bushing model developed which uses standard elements provided by DADS. The proposed methods are applied to the rubber bushings of the lower control arms of a rear suspension of a 1994 Ford Taurus model. Then, the forces computed for the rubber bushing model are analyzed and compared with the Voigt model in time and frequency domains.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.11
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• pp.1244-1248
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• 2009

Although rubber components are extensively used in mechanic parts. There are still a lot of difficulties in designing the rubber components applied in complex shapes and preloaded states because of the complicated material properties. One of the most important parameters for more detailed and accurate mechanical analysis during the development stages is the dynamic characteristics of the rubber components. It is well known that the dynamic properties of rubber are dependent on frequency as well as static preload. Consequently, a large number of experiments have to be conducted to identify the dynamic stiffness of a rubber bush considering the various applied conditions. In this paper, an efficient experimental method is suggested, which estimates the dynamic stiffness of a rubber bush using rubber material test and static stiffness of the bush. This method is capable of predicting the dynamic stiffness of a rubber bush under various load conditions from minimized test data.

• Journal of the Korean Wood Science and Technology
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• v.26 no.1
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• pp.70-75
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• 1998

In this paper, the relationships between volumetric mixing ratio of rubber chip and physical and mechanical properties of wood/rubber composite panel was examined in order to investigate the mixture characteristics of wood and rubber chip. Because of the specific gravity of rubber differed from wood chip, physical properties of wood/rubber composite panel was shown very different values by mixing rate of chip element. Specific gravity in air-dry of composite panel was increased rapidly as volumetric percent of rubber chip was increased. Moisture content of composite panel was decreased as volumetric percent of rubber chip element was increased. This results was considered that wood weight is light and porosity material for moisture absorption. Compressive strength and modulus of rupture in bending test were decreased as volumetric percent of rubber chip increased. By mixing ratio control of chip elements, various wood/rubber composite panel can be applicable to every interior materials such as subfloor, playground, and exterior materials such as road blocks for recreational facilities in garden and forest and city parks.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.1
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• pp.36-44
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• 2005

Nowadays, various kind of rubber-like materials are used in industry. These are usually installed in automobiles, trains, etc. They work as dampers or important parts in the system, and the applications for rubber-like materials are increasing. In the past days, rubber engineers and designers predicted rubber material behaviors by the analytic method for limited problems. With the progress of digital computers, Finite Element Methods is widely used for analyzing the rubber-like materials. The popular methods predicting rubber material property are curve fitting and least square method, but there are some problems such as low precision and tedious solving process. Here, we introduce a method estimating rubber material property by successive zooming genetic algorithm(SZGA). The proposed algorithm offers more precise rubber property. To demonstrate the effectiveness of the proposed algorithm, we compared this method with Haines & Wilson's method, MARC, ABAQUS.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.12
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• pp.561-566
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• 2005

This paper describes electrical resistivity, dielectric strength, thermal conductivity, thermal stability and tensile strength of mica sheet impregnated with silicone rubber resin or silicone rubber resin containing alumina powder. The mica sheet impregnated with silicone rubber resin had higher electrical resistivity, dielectric strength and tensile strength than those of virgin mica sheet. Electrical resistivity of mica sheet impregnated with silicone rubber resin containing alumina increased with increasing the amount of alumina. However, dielectric strength and tensile strength of mica sheet impregnated with silicone rubber resin containing alumina decreased with increasing the amount of alumina. The mica sheet impregnated with silicone rubber resin had lower thermal conductivity than that of virgin mica sheet. However, thermal conductivity of mica sheet impregnated with silicone rubber resin conatining alumina increased with increasing the amount of alumina. In the case of thermal stability, thermal degradation of virgin mica sheet and impregnated mica sheet with silicone rubber resin did not occur up to $1100^{\circ}C$ and $400^{\circ}C$, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.216-219
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• 2002

Much quantity of anti-tracking agent, ATH is added to the silicone rubber for the protection of silicone rubber against surface discharge. Hydrophobicity recovery properties of silicone rubber could be different by the content, surface treatment state and particle size of ATH. Because hydrophobicity of silicone rubber is depend much on the surface state of ATH. In this paper, the properties of silicone rubber is investigated according to the addition of different particle size of ATH to the silicone rubber. Hydrophobicity recovery properties and arc resistance of silicone rubber were investigated according to the addition of different particle size of ATH. Hydrophobicity recovery properties of silicone rubber were evaluated by the measurement of contact angle.