• Transactions of the Korean Society of Automotive Engineers
• /
• v.18 no.3
• /
• pp.74-79
• /
• 2010

Automotive industries are interested in material development with low weight and recycling. Grommet is made from EPDM at rubber and used as an automotive component. The nonlinear material properties of rubber are important to predict the behaviors of rubber product. This study concerns material property test to achieve stress-strain curve. Curve fitting is carried out to obtain the nonlinear material constant. The nonlinear material constants of rubber are used for the nonlinear finite element analysis. The results of finite element analysis is executed to predict the behavior property of grommet.

• Elastomers and Composites
• /
• v.51 no.1
• /
• pp.38-42
• /
• 2016

For improving the heat loss of a refrigerator around door gasket, it is very important to reduce the amount of rubber magnet used, of which thermal conductivity is much higher than the plastics, and enhancing the magnetic properties of rubber magnet itself is crucial for this. In the present study, therefore, a relationship between the optimum conditions of rubber magnet fabrication process and raw material compositions in the ferrite powder/CPE binder compounds was investigated for finding a way to enhance the magnetic properties of rubber magnet. Magnetic attraction forces of a sample rubber magnet was measured as function of distance, and thermal properties of the sample ferrite powder/CPE binder compound were analyzed with TG/DTA thermal analyzer. As a results, a rubber magnet strip with enhanced magnetic properties was expected to be fabricated, of which raw material compound was prepared by compounding with higher ferrite magnetic powder concentration.

• Journal of the Korean Society for Precision Engineering
• /
• v.15 no.9
• /
• pp.117-126
• /
• 1998

For investigating rubber pad sheet metal forming process, the rubber pad deformation characteristics as well as the contact problem of rubber pad-sheet metal has been analyzed. In this paper, the behavior of the rubber deformation is represented by hyper-elastic constitutive relations based on a generalized Mooney-Rivlin model. Finite element procedures for the two-dimensional responses, employing total Lagrangian formulations are implemented in an implicit form. The volumetric incompressibility condition of the rubber deformation is included in the formulation by using penalty method. The sheet metal is characterized by elasto-plastic material with strain hardening effect and analyzed by a commercial code. The contact procedure and interface program between rubber pad and sheet metal are implemented. Inflation experiment of circular rubber pad identifies the behaviour of the rubber pad deformation during the process. The various form dies and scaled down apparatus of the rubber-pad forming process are fabricated for simulating realistic forming process. The obtaining experimental data and FEM solutions were compared. The numerical solutions illustrate fair agreement with experimental results. The forming pressure distribution according to the dimensions of sheet metal and rubber pads, various rubber models and rubber material are also compared and discussed.

• Journal of Mechanical Science and Technology
• /
• v.20 no.4
• /
• pp.473-481
• /
• 2006

Predicting fatigue life by numerical methods was almost impossible in the field of rubber materials. One of the reasons is that there is not obvious fracture criteria caused by nonstandardization of material and excessively various way of mixing process. But, tearing energy as fracture factor can be applied to a rubber-like material regardless of different types of fillers, relative to other fracture factors and the crack growth process of rubber could be considered as the whole fatigue failure process by the existence of potential defects in industrial rubber components. This characteristic of fatigue failure could make it possible to predict the fatigue life of rubber components in theoretical way. FESEM photographs of the surface of industrial rubber components were analyzed for verifying the existence and distribution of potential defects. For the prediction of fatigue life, theoretical way of evaluating tearing energy for the general shape of test-piece was proposed. Also, algebraic expression for the prediction of fatigue life was derived from the rough cut growth rate equation and verified by comparing with experimental fatigue lives of dumbbell fatigue specimen in various loading condition.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2002.11b
• /
• pp.244-249
• /
• 2002

Rubber seat is extensively used to reduce the vibration of machine or structure. Over the years an enormous effort has been put into developing procedures to provide properties of rubber material for design function. However, there are still a lot of difficulties to analyze static characteristics of rubber components with hyper elasticity and nonlinear large deformation. In this paper material property is obtained by strain-stress curve using a tension test. Mooney-Rivlin Coefficients are gotten by fitting strain-stress curve. The visco-elastic characteristics of refrigerator rubber mount is determined by using ANSYS. And to minimize the rubber stiffness, the rubber seat shape optimization is performed.

• Journal of the FoodService Safety
• /
• v.5 no.1
• /
• pp.1-4
• /
• 2024

This study investigated the effect of sodium hypochlorite and ethanol on reducing Staphylococcus aureus on gloves depending on material and food contaminant. S. aureus inoculated onto rubber gloves with various organic substances (pork extract, perilla leaf extract, and 0.2% peptone water) and inoculated rubber gloves were stored in a desiccator at 100% RH and 25℃ for 24 h before treatments with distilled water, ethanol, or sodium hypochlorite. Levels of S. aureus were significantly reduced on both types of rubber gloves when treated with ethanol and sodium hypochlorite. However, sodium hypochlorite treatment resulted in 3.27 log CFU/each of S. aureus in pork extract on nitrile gloves, indicating that the effectiveness of disinfection may vary depending on the glove material and the type of organic substance. The results of this study suggest that ethanol treatment is the most effective disinfection method for S. aureus on rubber gloves, regardless of the material and organic substances.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.07a
• /
• pp.890-893
• /
• 2001

Two-layer self bonding insulating tape consists of butyl rubber(IIR ; Isobutylene-isoprene rubber) adhesive layer and polyethylene protective film. Butyl rubber have inherent characteristics such as resistance to corrosion and water, low temperature flexibility, excellent electrical insulating properties also resistance to environmental effect such as ozone and ultraviolet. Polyethylene film was used for the purpose of good insulating properties and resistance to ozone and ultraviolet. The tape was manufactured using extrusion and calender method.

• Smart Structures and Systems
• /
• v.6 no.8
• /
• pp.889-903
• /
• 2010

Idea of using piezoelectric materials with flexible structures made of rubber-like materials is quite novel. In this study a non-linear finite element model based on updated Lagrangian (UL) approach has been developed for dynamic response and its control of rubber-elastic material with surface-bonded PVDF patches/layers. A compressible stain energy density function has been used for the modeling of the rubber component. The results obtained are compared with available analytical solutions and other published results in some cases. Some results are reported as new results which will be useful for future references since the number of published results is not sufficient.

• Elastomers and Composites
• /
• v.41 no.3
• /
• pp.157-163
• /
• 2006

In this study, the wettability and mechanical properties of silicone rubber impression material were studied by using precipitated silica and fumed silica with different particle size and polarity (hydrophilic/hydrophobic). Curing time of impression material depended on the particle size of fumed silica. The curing time delayed about 9 minutes by using A300, which was the fumed silica with the smallest particle size among the silica used in this study. Wettability of rubber impression material improved with the introduction oi hydrophobic fumed silica(R972). Also, the optimum flow and mechanical properties could be obtained by using blended silica with the 90: 10 ratio of precipitated and fumed silica.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.19 no.5
• /
• pp.125-133
• /
• 2011

The wear of rubber track being in contact with the road surface is an important subject because it decreases the traction performance and the operating efficiency of tracked vehicle. For the above reasons, many attempts have been made to quantitatively calculate the rubber track. However, it depends on the experimental methods which are highly time- and cost-consuming. Therefore, the numerical simulation approach is highly desirable, but it needs to model the complex geometry and the material behavior in details as well as the interaction with the road surface. In this study, the rubber track and its material behavior are elaborately modeled since these factors are very important in the prediction of the wear rate of the rubber track. Accordingly to the studies on the rubber wear by previous investigations, it has been found that the wear is greatly influenced by the frictional energy. The frictional energy of rubber track is computed by utilizing the 3D finite element analysis of the rubber track, and the wear rate is evaluated making use of the frictional energy and a wear model.