• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.6
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• pp.747-754
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• 2004

The nonlinear finite element analysis for deformation characteristics of a power steering hose during the swaging process is performed in order to investigate the stress and the strain levels of the hose components. Power steering hose consists of components such as rubber hose, nylon, nipple and sleeve. Moreover, the numerical analysis requires the consideration of material, geometry and boundary nonlinearities. To evaluate the rubber hose strength, the measured stresses and strains are compared with tension and compression test data. Contact force is also a principal factor to examine whether rubber hose is break away from sleeve and nipple or not.

• Composites Research
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• v.21 no.1
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• pp.40-45
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• 2008

Rubber hose assembly for automotive hydraulic brake during operation is subject to combined stresses of cyclic pressure, cyclic bending and torsion as well as thermal load. The rubber hose is composed of ethylene-propylene diene monomer(EPDM) rubber layers reinforced by polyvinyl acetate(PVA) braided fabrics. A durability tester with loading rigs for inducing the above cyclic stresses was used to investigate failure mechanisms in the rubber hose assembly. Failure examination was performed at every 100 thousands cycles of bending and torsion. Hose samples were sectioned with a diamond-wheel cutter and then polished. The polished surface was observed by optical microscope and scanning electron microscope (SEM). Some interfacial delamination with a length of about 1mm along the interface between EPDM rubber and PVA fabrics was shown at the test cycles of 400,000. The delamination induced some cracking into the outer rubber skin layer to leading the final rupture of the hose.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.9
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• pp.915-923
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• 2007

Rubber hoses for automobile radiators are apt to be degraded and thus failed due to the influence of contacting stresses of air and coolant liquid under thermal and mechanical loadings. The aging behaviors of the skin part of the hoses due to thermo-oxidative and electro-chemical stresses were experimentally analyzed. Through the thermo-oxidative aging test, it was shown that the surface hardness IRHD(International Rubber Hardness Degrees) of the rubber increased with a considerable reduction of failure strain as the aging time and temperature increased. On account of the penetration of coolant liquid into the skin part influenced by the electro-chemical degradation(ECD) test the weight of the rubber hose increased, whereas their failure strain and IRHD hardness decreased. The hardness of the hose in the side of the negative pole was the most deteriorated at the test site of the hose skin just below the coolant surface.

• Journal of Power System Engineering
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• v.14 no.6
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• pp.54-60
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• 2010

The automotive air conditioning hose is used for connecting the components of air conditioner in a vehicle. The hose is usually manufactured by the swaging process to connect the rubber hose with the metal fitting at the end of the hose. The swaging process leads to various stress and strain configurations in the hose, which give a critical effect on the hose performance. In this paper, the deformation characteristics of an air-conditioning hose during the swaging process were analyzed using the nonlinear finite element method. Especially the rubber layers, which are contacted with the metal fittings, were divided with finer mesh density than the reinforcement braids to increase the solution accuracy. The material properties were obtained from experimental data, and the contact conditions were used in consideration of the real manufacturing process.

• Journal of Power System Engineering
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• v.7 no.2
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• pp.44-50
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• 2003

The power steering hose is a kind of high-pressure hose with reinforced braids in rubber material. It is usually manufactured through the swaging process. In this paper, the deformation characteristics of a power steering hose during the swaging process were analyzed using the nonlinear finite element method. The material properties were obtained on experiments, and the contact conditions were used in consideration of real manufacturing process. Investigations were focused on the stress and strain values of the hose and meta] components at the maximum jaw stroke and at the completion of the process. Especially, the results of inner rubber component were interpreted in detail, because of its important role in the hose efficiency.

• Elastomers and Composites
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• v.40 no.2
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• pp.83-92
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• 2005

To develop an automotive fuel hose suitable to the international environmental regulation, FKM rubber materials as an inner material of fuel hole were prepared with different chemical compositions. Measurement of the properties of thermal resistance, oil resistance, fuel resistance, gas permeability including fundamental properties were performed to investigate compatibility for a fuel hose material. Fundamental properties, thermal resistance, oil resistance, fuel resistance and permeability of FKM rubber materials were improved with fluorine content. When the carbon content was 20 phr, FKM compounds with fluorine contents of 66%, 09% and 71% were shown to satisfy the specification oi fuel hose. The gas permeability of NBR and FKM compounds was measured on the mixed fuel oils prepared with isooctane-toluene and gasoline-methanol. FKM rubber materials showed a small difference in penetrated amount of fuel and showed a permeability superior to NBR material. he permeability of FKM rubber materials was not influenced by the contents of fuel oil. Thermal properties of 69% FKM rubber experienced by permeability testing were not variated.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.9
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• pp.837-844
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• 2012

We considered an approach in terms of materials for improvement of insulation performance of vehicle rubber hoses. Ethylene propylene rubber(EPDM) for heater hoses in cooling system and acrylic rubber(AR) for intercooler hose in intake system were chosen for mixing for the vibration and noise performance. We modified EPDM and AR through changing compound of base polymer, reinforcement fillers and additives. Dynamic mechanical analysis(DMA) was used to measure viscoelastic properties such as shear modulus and loss factor($tan{\delta}$). Vehicle acceleration test was also conducted to observe indoor changes in insulation performance of hoses.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.6
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• pp.105-110
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• 2018

A concrete docking hose of pump car's boom pipe line have been used in many construction sites. They are long structures with continuous cornering, similar to a trunk of the elephant, characterized by a very high pressure resistance of 20MPa. They need flexible materials and structure in order to move the hose smoothy. But commercial concrete hose is hard to handle and heavy owing to adaption of steel reinforcement. In this study, it is tried an experimental approach to the characteristic of inner rubber layer and abrasion resistance. Also, we are investigated the bursting pressure according to the reinforcement of the hose and propose the usefulness of the hose reinforced with high strengthened aramid fiber.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.5
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• pp.1102-1106
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• 2008

It's necessary to invent a measure to deal with expected counter results when observing mechanical behaviors under the various operations and it can be done by measuring the stress and deformation characteristics of the Automotive Air-Conditioner Hose, which is a hose made up of a rubber hose, an aluminum sleeve and pipe. In this paper, characteristics of the stress and deformation characteristics of the Automotive Air-Conditioner Hose which plays an important role in circulation of refrigerant of an air conditioner in an automobile are analyzed using the finite element method.

• Journal of Applied Reliability
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• v.9 no.4
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• pp.275-290
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• 2009

This paper considers accelerated thermal degradation tests which are performed for rubber seal materials used for undersea tunnels constructed by immersion method. Three types of rubber seals are tested; rubber expansion seal, omega seal, and shock absorber hose. Main ingredient of rubber expansion seal is EPDM(Ethylene Propylene Diene Monomer) and that of both omega seal and shock absorber hose is SBR(Styrene Butadiene Rubber). The accelerated stress is temperature and an Arrhenius model is introduced to describe the relationship between the lifetime and the stress. From the accelerated degradation tests, dominant failure mode of the rubber seals is found to be the loss of elongation. The lifetime distribution and the service life of the rubber seals at use condition are estimated from the test results. The acceleration factor for three types of rubber seals are also investigated.