• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.4
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• pp.602-609
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• 2001

This paper is concerned with the orthotropic problem of diaphragm-type air springs which consist of rubber linings, nylon reinforced rubber composite and bead ring. The analysis is carried out with a finite element method developed to consider the orthotropic properties, geometric nonlinearity using four-node degenerated shell element with reduced integration. Physical stabilization scheme is used to control the zeroenergy mode of the element. The analysis includes an inflation analysis and a lateral analysis of an air spring for the deformed shape and the spring load with respect to the vertical and l ateral deflection. Numerical results demonstrate the variation of the outer diameter, the fold height, the vertical force and the lateral force with respect to the inflation pressure and the lateral deflection.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.8 s.179
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• pp.1968-1799
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• 2000

A warpage analysis program has been developed for fiber-reinforced injection molded parts. The warpage is predicted from the residual stress and anisotropic thermo-mechanical properties coupled with fiber orientation in the integrated injection molding simulation. A simple elastic model is used for the calculation of thermally and pressure-induced residual stresses which are employed as the initial conditions in the structural analysis. To improve the reliability of warpage analysis, a new triangular flat shell element superimposing well-known efficient plate bending and membrane element is presented. The numerical examples address the necessity to use anisotropic models for fiber-reinforced materials and show that predicted warpage is in good agreement with experimentally measured one.

• 한국터널공학회:학술대회논문집
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• 2005.04a
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• pp.259-261
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• 2005

The needs of improving the performance of wet shotcrete has become one of the most important issues in the tunnel field. The aim of this paper is to research the construction method of reinforced shotcrete using structural polymer fiber which exhibits a high quality in toughness and durability for the support of tunnel.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.04a
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• pp.167-174
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• 2003

It is absolutely natural to be interested in durability and safety of the structure under shear behavior. To fulfill this desire, a comparison on the shear behavior between steel fiber reinforced concrete both simple and continuous beams is done to use in the field working. Several operations are conducted : First of all, plan for optimal combination is standardized. Second, resistance for shear has been generalized in that it is decided by combination of individual elements. Third, as the fracture of tensile bar leads to destruction of specimen, shear behavior of whole specimen is decided by stress working on tensile bar. It should be generalized for other specimens also. Forth, evidence of the softness of steel fiber reinforced concrete beam by experiment lead to application in the fields. Finally, numeral values of the steel fiber reinforced concrete are analyzed and the result is compared to those of experiments. With these consequences, this study was done for the application to dynamic structures such as bridges and the repair and rehabilitation.

• Computational Structural Engineering
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• v.4 no.3
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• pp.99-106
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• 1991

Flexural load-deflection relationships for steel fiber reinforced concrete(SFRC) are dependent on the tensile and compressive constitutive behaviors of the material, which may be refined in the presence of strain gradients under flexural loads. Considering the relatively large amount of flexural test results available for steel fiber reinforced concrete, and the relative ease of conducting such tests in comparison with direct tension tests, it seems to be important to obtain basic information on the tensile constitutive behavior of SFRC from the result of flexural tests. For this purpose "System Identification" technique was used for interpretating the flexural test data and it was successful in obtaining optimum sets of main parameters which explain the tensile constitutive behavior of SFRC under flexure.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1802-1806
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• 2007

The most important factor is the roadbed bearing capacity at concrete track construction. Particularly, in case of rehabilitation, it is essential to secure the uniform roadbed stiffness to prevent the irregular settlement. In this study, reinforced effect of the geotextiles is investigated which is applied to concrete track rehabilitation. The geotextiles is installed two or three layers as the condition of the ground and structure. The reinforced effect of geotextiles is confirmed by the strain gage attached on the geotextiles surface.

• International Journal of Highway Engineering
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• v.16 no.6
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• pp.87-93
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• 2014

PURPOSES : To evaluate the feasibility of cut waste fishing net as a reinforced fiber for concrete. METHODS : Strength characteristics of fiber reinforced concrete using waste fishing net were investigated. The cut waste fishing nets with 4~5cm length were putted into the soil-cement and cement concrete for pavement slab. RESULTS : Compression and tensile strength of fiber reinforced concrete using waste fishing net were increased. CONCLUSIONS : It was concluded that cut waste fishing net can be used as a reinforced fiber for cement concrete. However, sometimes using cut waste fishing net leads to decrease the strength; therefore, further researches are needed for real project.

• Proceedings of the Korea Concrete Institute Conference
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• 1996.04a
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• pp.146-152
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• 1996

Polypropylene fiber reinforced mortar and concrete as civil material or architectural material have been used in America and British etc, and have been researched. Polypropylene fibers have many advantages in many points ; in economical costs, chemical stability and durability. It has been reported that polypropylene fiber can control restrained tensile stresses and cracks and increase toughness, resistance to impact, corrosion, fatigue and durability. This study has been performed to obtain the properties of polypropylene fiber reinforced concrete such as compressive strength, flexural strength, toughness, slump, drying shrinkage crack and drying shrinkage characteristics. The test variables are fiber contents, fiber length, fiber types, and so on. From the results of this study, we can expect the effects of the admixtures of polypropylene fiber about strength and drying shrinkage properties in concrete and mortar.

• Proceedings of the Korea Concrete Institute Conference
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• 1996.04a
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• pp.1-6
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• 1996

Cellulose fiber reinforced cement composites manufactured by the slurry-dewatering process have found broad applications in thin cement products as replacement for asbestos cement. This paper focuses on the durability characteristics of these composites under different aging conditions. The effects of wetting-drying and freezing-thaw cycles, carbonation, and exposure to hot and humid environments on the structure and properties of cellulose fiber-cement composites were investigated. The predominant mechanisms of aging in the composites were identified through investigation of structure-property relationships. Measures to control these aging mechanisms were diversed and evaluated. Refined cellulose fiber-cement composites are shown to possess excellent durability characteristics under the effects of various aging processes.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.122-125
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• 2000

CFRD (Concrete Faced Rockfill Dam) face slab concrete has a much capability to occur crack due to drying shrinkage, hydration heat and bas compaction etc. Because of crack of concrete induce structural problem and decrease durability of concrete, it is need to reduce crack of concrete. This is an experimental study to analyze the effect of fiber reinforced on CFRD face slab concrete. for this purpose, it was investigated and analyzed the engineering properties of plain concrete and polypropylene fiber reinforced concrete (PFRC) according to test result ; the test include slump, air content, compressive strength, tensile strength, drying shrinkage and permeability etc. As the results, it was found permeability and drying shrinkage of PFRC less than that of plain concrete.