• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.5
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• pp.141-153
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• 1999

A finite element procedure for the analysis of rubber-like hyperelastic material is developed. The volumetric incompressiblity conditions of the rubber deformation is included in the formulation by using penalty method. In this paper, the behavior of the rubber deformation is represented by hyperelastic constitutive relations based on a generalized Mooney-Rivlin model. The principle of virtual work is used to derive nonlinear finite element equation for the large displacement problem and presented in total-Lagrangian description. The finite element procedure using analytic differentiation resulted in very close solution to the result of the well known commercial packages NISAII AND ABAQUS. Numerical tests show that the results from the numerical differentiation method coincide very well with those from the analytic method and the well known commercial packages in static analysis. The convergency of rubber usingν iteration method is also discussed.

• International Journal of Automotive Technology
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• v.7 no.6
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• pp.741-747
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• 2006

It has been almost impossible to predict the fatigue life in the field of rubber materials by numerical methods. One of the reasons is that there are no obvious fracture criteria and excessively various ways of mixing processes. Tearing energy is considered as a fracture criterion which can be applied to rubber compounds regardless of different types of fillers, relative to other fracture factors. Fatigue life of rubber materials can be approximately predicted based on the assumption that the latent defect caused by contaminants or voids in the matrix, imperfectly dispersed compounding ingredients, mold lubricants and surface flaws always exists. Numerical expression for the prediction of fatigue life was derived from the rate of rough cut growth region and the formulated tearing energy equation. Endurance test data for dumbbell specimens were compared with the predicted fatigue life for verification. Also, fatigue life of industrial rubber components was predicted.

• Elastomers and Composites
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• v.55 no.4
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• pp.314-320
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• 2020

This study focused on experiments with polyethylene glycol (PEG) and glycidyl methacrylate (GMA), which are functional additives for water-expandable rubber. Polychloroprene rubber (CR)/superabsorbent polymer (SAP) composites were prepared and their cure behaviors, mechanical properties, water absorption rates, and surface morphology were measured based on the functional additives applied. When PEG and GMA were applied to the composites, the water absorption rate increased-including the initial rate-compared to that measured when functional additives were not used. The results also show that PEG has a hydrophilic functional group, which allows it to absorb more water, and GMA acts as a coupling agent between CR and SAP. However, with the introduction of functional additives, the cure rate slowed down and the mechanical properties also decreased.

• Journal of Information Science Theory and Practice
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• v.7 no.4
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• pp.56-64
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• 2019

Planting intercropping in rubber plantations is another alternative for generating more income for farmers. However, farmers still lack the knowledge of choosing plants. In addition, information for decision making comes from many sources and is knowledge accumulated by the expert. Therefore, this research aims to create a decision support system for growing rubber trees for individual farmers. It aims to get the highest income and the lowest cost by using semantic web technology so that farmers can access knowledge at all times and reduce the risk of growing crops, and also support the decision supporting system (DSS) to be more intelligent. The integrated intercropping ontology and rule are a part of the decision-making process for selecting plants that is suitable for individual rubber plots. A list of suitable plants is important for decision variables in the allocation of planting areas for each type of plant for multiple purposes. This article presents designing and developing the intercropping ontology for DSS which defines a class based on the principle of intercropping in rubber plantations. It is grouped according to the characteristics and condition of the area of the farmer as a concept of the rubber plantation. It consists of the age of rubber tree, spacing between rows of rubber trees, and water sources for use in agriculture and soil group, including slope, drainage, depth of soil, etc. The use of ontology for recommended plants suitable for individual farmers makes a contribution to the knowledge management field. Besides being useful in DSS by offering options with accuracy, it also reduces the complexity of the problem by reducing decision variables and condition variables in the multi-objective optimization model of DSS.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.8
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• pp.1045-1050
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• 2010

Fatigue analysis and lifetime evaluation are very important in design procedure for assuring the safety and reliability of rubber components for mechanical systems. Till recently, the technology for the design, analysis, and evaluation of rubber products was required to manufacture rubber products with high quality, fidelity, and reliability. However, in the rubber-manufacturing companies in Korea, the processes of compound mixing, manufacturing of rubber products, and improvement of rubber properties are based on the trial-and-error method and experience. The objectives of this study are to establish methods for testing rubber materials, to develop a database of the properties of rubber materials, to evaluate the performance of rubber components, and to develop a system for predicting fatigue life. A method to predict fatigue-life of rubber components was proposed; in this method, the finite-element analysis and fatigue damage parameter as determined from a fatigue test are incorporated.

• Elastomers and Composites
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• v.49 no.2
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• pp.95-102
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• 2014

The noise between floors of apartment has been hot issue nowadays. In order to improve the noise insulation performance, we proposed the antivibration rubber system which can be applied to the floor system for sound insulation. Among various types of elastomer, butyl rubber showed the good aging characteristic, low rebound resilience and high damping factor. Thus, the butyl rubber was selected as a basic rubber for antivibration rubber system. The effects of type and loading amounts of carbon black on antivibration properties of butyl rubber were studied. The increase of surface area and the content of carbon black resulted in high bound rubber fraction, high mechanical property, low rebound resilience, and high damping factor of butyl rubber. Based on the results of this study, the new antivibration rubber was prepared and applied to the floor system for sound insulation. The impact sounds of floor system proposed in this study were 40 dB and 43 dB in cases of light weight and heavy weight impact sound, respectively.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.6
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• pp.56-62
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• 2005

The fatigue analysis and lifetime evaluation are very important in design procedure to assure the safety and reliability of the rubber components. Fatigue lifetime prediction methodology of the rubber component was proposed by incorporating the finite element analysis and fatigue damage parameter from fatigue test. Finite element analysis of 3D dumbbell specimen and rubber component were performed based on a hyper-elastic material model determined from material test. The Green-Lagrange strain at the critical location determined from the FEM was used for evaluating the fatigue damaged parameter of the natural rubber. Fatigue life of the rubber component are predicted by using the fatigue damage parameter at the critical location. Predicted fatigue lifes of the rubber component agreed fairly well the experimental fatigue lives.

• Polymer(Korea)
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• v.38 no.4
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• pp.425-433
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• 2014

In this study, microstructure and gel content (C-C) of polybutadiene rubber (PBR) were investigated using various techniques including ASTM D 3616, attenuated total reflectance Fourier transform infrared spectrometry (ATR FTIR), differential scanning calorimetry (DSC) and nuclear magnetic resonance spectroscopy (NMR). The ATR FTIR spectra of the samples were investigated to determine the cis, trans, 1, 2-vinyl and the C-C gel content in PBR. The absorbance ratios of specific peaks in different grades of PBR were correlated with the C-C gel content measured by the ATR FTIR techniques. Physico-mechanical and rheological properties of rubber compounds based on BR with various amounts of gel were determined. The results showed that there is an acceptable correlation between these properties and the C-C gel content of PBR.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.507-512
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• 2003

A finite element analysis for near-net-shape forming of Al6061 powder was performed under warm pressing. The advantages of warm compaction by rubber isostatic pressing were discussed to obtain parts with better density distributions. To simulate densification and deformed shape of a powder compact during warm pressing, the elastoplastic constitutive equation based on yield function of Shima-Oyane was implemented into a finite element program(ABAQUS). The hyperelastic constitutive equation based on the Ogden strain energy potential was employed to analyze nonlinear elastic response of rubber. Finite element results were compared with experimental data for Al6061 powder compacts under warm pressing.

• Polymer(Korea)
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• v.38 no.5
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• pp.664-670
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• 2014

The effects of different filling materials and stabilizers in polymer based materials that are used as shoe soles in the shoemaking industry on the mechanical properties (strength, failure, tensile, tearing, bending etc.) of the final products have been examined in this study. Natural rubber (NR RSS3) and styrene-butadiene rubber (SBR 1502) were used as the main matrix material. New compounds were formed by replacing the fillings in the general compound of the existing factory ($SiO_2$, $CaCO_3$) with 40% (1200 g) blast furnace flue dust, rice husk, reclaimed rubber (recycled) and wood ash. Comparison of the new compounds with the existing compounds revealed a decrease in hardness, density, dimension stability, bending, tearing, % elongation and failure strength and an increase in wearing.