• 한국소음진동공학회논문집
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• 제23권11호
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• pp.1012-1019
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• 2013

Recently, awareness of noise is increased and high performance sound insulation performance wall is designed. But in spite of installing high performance sound insulation performance wall, sound insulation performance in space is reduced by door. In this study, Sound insulation performance of doors which commonly used in buildings was measured to analyze current situation in the field and effect of method which increase sound insulation performance is analyzed quantitatively. As a result, sound insulation performance of doors which commonly used in buildings is FSTC 17~29 and can be increased about 2~3 dB by install rubber seal or mohair.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.326-331
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• 2011

Aluminum extruded panel used in a high speed train shows high stiffness, however, its sound insulation performance is remarkably decreased by local resonance phenomena. In this paper, improvement strategy of the sound insulation performance is proposed for the floor extruded panel used in HEMU-400x, 400km/h class next generation high speed train under development, and the improvement effect is verified by experiment. Aluminum extruded panel specimen for the floor is manufactured and urethane foam is installed in the core of the panel. Based on ASTM E2249-02, intensity transmission loss is measured and the improvement effect in local resonance frequency band is verified. Finally, improvement effect of the sound insulation performance is estimated on the layered floor structure including the foamed aluminum panel.

• Advanced Composite Materials
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• 제17권1호
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• pp.25-40
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• 2008

The research and development in soundproof materials for preventing noise have attracted great attention due to their social impact. Noise insulation materials are especially important in the field of soundproofing. Since the insulation ability of most materials follows a mass rule, the heavy weight materials like concrete, lead and steel board are mainly used in the current noise insulation materials. To overcome some weak points in these materials, fiber reinforced composite materials with lightweight and other high performance characteristics are now being used. In this paper, innovative insulation sheet materials with carbon and/or glass fabrics and nano-silica hybrid PU resin are developed. The parameters related to sound performance, such as materials and fabric texture in base fabric, hybrid method of resin, size of silica particle and so on, are investigated. At the same time, the wave analysis code (PZFlex) is used to simulate some of experimental results. As a result, it is found that both bundle density and fabric texture in the base fabrics play an important role on the soundproof performance. Compared with the effect of base fabrics, the transmission loss in sheet materials increased more than 10 dB even though the thickness of the sample was only about 0.7 mm. The results show different values of transmission loss factor when the diameters of silica particles in coating materials changed. It is understood that the effect of the soundproof performance is different due to the change of hybrid method and the size of silica particles. Fillers occupying appropriate positions and with optimum size may achieve a better effect in soundproof performance. The effect of the particle content on the soundproof performance is confirmed, but there is a limit for the addition of the fillers. The optimization of silica content for the improvement of the sound insulation effect is important. It is observed that nano-particles will have better effect on the high soundproof performance. The sound insulation effect has been understood through a comparison between the experimental and analytical results. It is confirmed that the time-domain finite wave analysis (PZFlex) is effective for the prediction and design of soundproof performance materials. Both experimental and analytical results indicate that the developed materials have advantages in lightweight, flexibility, other mechanical properties and excellent soundproof performance.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 추계 학술논문 발표대회
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• pp.77-78
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• 2017

In this study, the effect of insulation curing for mass concrete wall according to thickness and curing period was evaluated by thermal analysis.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.406-409
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• 2002

The primary insulation system used in an oil-filled transformer is Kraft paper, wood, porcelain and, of course, oil. Modern transformers use paper that is chemically treated to improve its tensile strength properties and resistance to aging caused by immersion in oil. These insulation papers are mainly aged to thermal stress. Over the course of the insulation paper and oil's life it is exposed to high temperatures, oxygen and water. Its interaction with the steel of the tank and core plus the copper and aluminium of the windings will eventually cause the chemical properties of the oil to decay. High temperature have an effect on mechanical strength of cellulous paper using the layer insulation. We made two aging cell in which thermal aging tests of insulation papers and mineral oil are conducted. It is measured dielectric strength, number of acid, moisture, etc. of insulation paper and oil aged in the aging cells.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1578-1583
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• 2003

LAVA-ERVC experiments have been performed to investigate the effect of insulation design features on the coolability in case of the external reactor vessel cooling (ERVC). All the 4 tests have been performed using Alumina iron thermite melt as a corium simulant. Due to the limited steam venting through the insulation, steam binding occurred inside the annulus in the KSNP case simulation. On the contrary, in the tests which were performed for simulating the APR1400 insulation design, sufficient water ingression and steam venting through the insulation lead to effective cool down of the vessel characterized by nucleate boiling. It could be found from the experimental results that modification of the insulation design allowing sufficient ventilation could increase the positive effects of the external reactor vessel cooling.

• 한국전기전자재료학회논문지
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• 제25권6호
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• pp.474-480
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• 2012

Diagnostic tests were performed on two high voltage(HV) motor stator windings. These tests included the measurement of insulation resistance, polarization index, AC current, dissipation factor($tan{\delta}$) and partial discharge(PD) magnitude. Surface contamination of HV motor stator windings has an effect on the AC current and $tan{\delta}$. When the stator windings were finished cleaning and insulation reinforcement, the increase rate of AC current(${\Delta}I$) and dissipation factor(${\Delta}tan{\delta}$) were very small compared to those before cleaning. However, the PD magnitude remained the same. These tests show that cleaning and insulation reinforcement of HV motor stator windings can reduce the insulation failure.

• 설비공학논문집
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• 제28권9호
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• pp.350-354
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• 2016

Although fibrous insulations are generally used with resistive insulation type, metallic insulation is proper matter to satisfy low head-loss and equipment life when considering the specific condition, especially for Nuclear power plant. Common insulation is resistance insulation with a low thermal conductivity. but RMI is made of sheet plate with low emissivity and closed air space. Thermal radiation is blocked by stainless steel with low emissivity. Thermal conductivity and thermal convection are blocked by closed air space. This study shows the changes and effects of the heat loss according to shape and method of stacking sheet plates inserted into the insulation and analyzed the most optimized way for thermal insulation performance. The result shows that using sheet plate structure through raised and protruding shape processing was the appropriate model to optimize thermal performance. Additionally, insulating performance of RMI improved by placing the sheet plate in a high temperature region intensively.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1462-1465
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• 1996

This paper evaluated dielectic characteristics on EPR, Polyester and insulation of these different interface. Dielectric characteristics of insulation rubber, Polyester increace greatly according as temperature increases have no effect on applied voltage and pressure. On the condition that interface exists, we confirmed that dielectric characteristics had been influence on semiconductor which had high $tan{\delta}$.

• 한국지반공학회논문집
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• 제33권8호
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• pp.17-27
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• 2017

우리나라 북동부에 위치하고 있는 강원지역은 겨울철 일 평균온도가 영상권을 유지하는 타 지역들과는 달리 일평균온도가 영하로 떨어지는 가장 추운 지역이다. 이에따라 지속적으로 도로터널의 라이닝부에 대한 동결피해 발생 사례가 보고되고 있으나 동결피해 저감을 위한 단열설계 기준 및 관련 연구는 아직까지 매우 부족하다. 본 연구에서는 단열공법 적용에 따른 도로터널의 동결저감 효과를 분석하기 위하여 겨울철 강원지역 도로터널의 지반특성과 기후특성을 고려한 해석적 연구를 수행하였다. 그 결과, 라이닝부의 콘크리트와 숏크리트 두께의 차이는 동결심도에 큰 영향을 미치지 않는 것으로 나타났으나 단열재의 적용 시에는 동결심도가 크게 감소하는 것으로 나타났다. 또한 배면지반의 열전도율과 외기온도 지속지간의 변화에 따라서 동결심도가 큰 영향을 받으므로 이러한 영향을 고려하여 단열재의 두께를 산정하여 적용한다면 우수한 동결저감 효과를 보일 것으로 판단된다.