방음판의 흡음률 측정방법 제안을 위한 기초 연구

오양기,김하근 한국음향학회 2023 韓國音響學會誌 Vol.42 No.2

Sound barrier walls are the most basic way to cope with noise problems in urban residential environments. The most important acoustic function of sound insulation board is represented by sound transmission loss and sound absorption coefficient. However, Korea has not yet established a standard for measuring the sound absorption rate of sound insulation boards. In addition, even in the European standard, where the overall acoustic standard of soundproofing boards has already been established, the sound absorption rate is applied only to the standard for measuring the sound absorption rate of general building finishing materials, and a separate measurement method considering the characteristics of soundproof walls and soundproofing boards is not presented. The sound absorption coefficient should be evaluated by summing up the energy absorbed into the material as well as the energy transmitted through the material, but the current European standard has a problem in that the transmitted sound energy is not taken into account. In this paper, we reviewed the sound absorption coefficient measurement standards of sound insulation boards currently being presented, and verified the difference between the results and the new measurement method considering transmission sound for sound insulation boards actually used in Korea. 방음벽은 도시 주거환경의 소음문제에 대응하기 위한 가장 기본적인 방법이다. 방음판의 가장 중요한 음향적기능은 음향투과손실과 흡음률로 표시된다. 특히 주거시설이 밀집되어있는 도심구간의 철도나 간선도로에서 원하지않는 반사음에 의한 2차 소음 문제를 최소화하기 위하여는 방음판의 흡음성능이 중요하다. 그러나 아직까지 우리나라는 방음판의 흡음률 측정방법에 관한 규격이 마련되어있지 않다. 또한 방음판의 전반적인 음향규격이 이미 만들어져있는 유럽규격에서조차 흡음률에 관해서는 일반적인 건축마감재료의 흡음률 측정기준을 준용하고 있을 뿐, 방음벽과방음판의 특성을 감안한 별도의 측정방법을 제시하지 못하고 있다. 흡음률은 재료의 내부로 흡수된 에너지 뿐 아니라재료를 투과한 에너지까지 합산하여 평가되어야 하는데 현재의 유럽규격은 투과음 에너지를 감안하지 못하고 있는문제를 안고 있다. 이 논문에서는 현재 제시되고 있는 방음판의 흡음률 측정 규격에 대해 고찰하고, 우리나라에서 실제 사용되고 있는 방음판을 대상으로 투과음을 감안한 새로운 측정방법과의 결과 차이를 검증하였다. 아울러 새로운 방음판 흡음률 측정규격의 마련을 위한 기초적 아이디어를 제시하였다.

건축재료 흡음률의 현장측정시스템 개발

이강성(Lee, Gang-Seong),주문기(Chu, Mun-Ki),고효인(Ko, Hyo-In),홍지영(Hong, Ji-Young),오양기(Oh, Yang-Ki) 한국건축친환경설비학회 2014 한국건축친환경설비학회 논문집 Vol.8 No.6

There are a couple of measurement standards in measuring the absorption coefficient of building materials. Impedance tube method and reverberation room method are those standardized absorption coefficient measurement methods. While applicable to the development stage of certain absorptive materials and the measurement of random incident absorption coefficient of multi layered absorption complex, they are unable to be applied to in-situ measurement. There are needs for the in-situ measurement for the assessment of the efficient of absorption materials and for the remodelling design of existing rooms. This research deals with an in-situ absorption coefficient measurement system which is based on the calculation of energy from impulse response of incident and reflected signal on the same axis

방음판의 흡음률 규정에 관한 재고찰

주문기,전호민,정진연,오양기 대한건축학회지회연합회 2013 대한건축학회연합논문집 Vol.15 No.1

방음판 흡음률 규정의 경우 250㎐, 500㎐, 1㎑, 2㎑m이 평균흡음률이 70% 이상이면 이를 만족시키는 것으로 규정되어 있다. 방음판 측정결과 특정 주파수 대역에서의 흡음률이 아주 높을 경우 다른 대역의 흡음률이 아주 작게 나타나더라도 70%를 만족하면 되는 것으로 나타났다. 그리고 도로교통소음 실측과 선행연구를 통해 대형차의 소음레벨이 저주파 대역에서 집중되어 있고 특히 250㎐대역이 80㏈(A)를 상회하며 125 ㎐대역에서의 소음레벨도 65-68㏈(A)로 나타나 각각의 주파수 대역의 최저 흡음률과 저음을 고려한 흡음률 규정이 필요할 것으로 판단되었다.

그라파이트 인터칼레이션 컴파운드가 에폭시 복합재료의 흡,차음성에 미치는 영향

이병찬 ( Byung Chan Lee ),박규대 ( Gyu Dae Park ),최성규 ( Sung Kyu Choi ),김성룡 ( Sung Ryong Kim ) 한국복합재료학회 2015 Composites research Vol.28 No.6

팽창된 그라파이트 인터칼레이션 컴파운드에 에폭시 수지를 주입하여 제조한 복합재료의 흡·차음성을 연구하였다. 관내법을 이용하여 복합재료의 흡음률과 음향투과손실을 측정하였다. 주사전자현미경을 이용하여 에폭시 매트릭스 내부에 그라파이트 인터칼레이션 컴파운드가 무질서한 방향으로 균일하게 분산된 것을 확인하였다. 그라파이트 인터칼레이션 컴파운드 함량이 증가함에 따라 복합재료의 면밀도가 감소하였으며, epoxy/(GIC 20 wt%)복합재료의 면밀도는 순수 에폭시에 비하여 56% 감소하였다. 500~1000 Hz 주파수 영역에서 복합재료의 흡음률은 순수 에폭시에 비해 3배 정도 증가하였다. 그라파이트 인터칼레이션 컴파운드의 함량이 증가함에 따라 복합재료에 포함된 기공의 비율이 증가하여 순수 에폭시에 비하여 복합재료의 음향투과손실이 감소하는 것으로 판단된다. The sound absorption coefficient and sound transmission loss of graphite intercalation compound (GIC) included epoxy composites were investigated. Epoxy resin was infused into the expanded GIC and the impedance tube method was employed to measure the sound absorption coefficient and sound transmission loss. Scanning electron microscopy photographs showed uniform distribution of the GIC in the epoxy matrix. The surface density of epoxy/ GIC (20 wt%) composites decreased about 56% compared to that of pure epoxy. The sound absorption coefficient of composites increased about 3 times at the frequency range of 500~1000 Hz compared to the pure epoxy. The sound transmission loss of composites decreased with increasing the GIC content and it is attributed to the increase of pores in the composites.

흡음재 마감구조에 따른 흡음률 변화에 관한 연구

오진우(JinWoo Oh),이장현(JangHyun Lee),김학선(HakSun Kim),이정호(JungHo Lee),이수혁(SooHyuk Lee),김한샘(HanSam Kim) 한국소음진동공학회 2015 한국소음진동공학회 학술대회논문집 Vol.2015 No.10

Various absorber is used in the noise reduction equipments and acoustic construction site. Representative absorbers are Glass-wool and Poly-ester. Both of them has a high absorption coefficient. When the absorber is installed, absorber is needed finishing, perforated plate and film, to maintain the shape, prevent scatter and keep from water. These finishing layer cause shift of the absorption coefficient. Experiment was performed at acoustic facility(reverberant room) by referring KS I ISO 2805 standard.

복합시트의 구조가 흡,차음성에 미치는 영향

이병찬 ( Byung Chan Lee ),김성룡 ( Sung Ryong Kim ) 한국복합재료학회 2012 Composites research Vol.25 No.5

복합시트의 구조를 변화시켜 흡?차음성에 미치는 영향을 연구하였다. 폴리프로필렌 보드의 표면과 배면에 폴리에틸렌테레 프탈레이트 부직포를 핫 프레스로 융착하여 복합시트를 제조하였다. 면밀도가 0.64kg/m2인 부직포를 사용하여 제조한 복합시트의 흡음률은 0.1-0.2의 값을 나타내어 폴리프로필렌 보드의 흡음률에 비해 약 100~400%의 증가를 나타내었다. 폴리프로필렌 보드의 면밀도를 증가시키거나 복합시트 위에 반구형의 홈을 포함하는 경우에 복합시트의 투과손실이 증가하였다. 평판복합시트와 사인 파형을 가지는 복합시트의 구조를 변화시켜 만든 2가지 복합시트 구조에 따른 흡음률과 차음도의 변화를 조사하였다. The effect of structure on the sound absorption and sound transmission loss of composite sheet was investigated. A sheet of polypropylene was bonded by hot press with nonwoven fabric sheets of polyethylene terephthalate on the top side and the back side. Absorption coefficient of composite sheet using nonwoven fabric with surface density of 0.64kg/m2 was 0.1-0.2. It is 100-400% improvement compare to that of polypropylene sheet. The transmission loss of composite sheet was increased with surface density of polypropylene board and introduction of hemisphere hole on the surface of sheet. Two types of composite sheet were made using flat sheet and sine wave shaped sheet and the effect of sheet structure on the transmission loss was investigated.

시험방법에 따른 흡음률 비교

이재원(Lee, J.W.),구진회(Gu, J.H.),박형규(Park, H.K.),강대준(Kang, Dae-Joon) 한국소음진동공학회 2007 한국소음진동공학회 논문집 Vol.17 No.5

Today, the use of the sound absorptive material is increasing to improve the room acoustics in the auditorium and music hall, etc. Usually, the sound absorption materials have been used to enhance the performance of a noise barrier and improve the room acoustics in construction site. Generally, the sound absorbtion coefficients are the most important factor reflecting the sound absorbtion performance. There are two methods to measure the sound absorption coefficient. The first one is the reverberation room method, and the second is the impedance tube method. In this study, we measure the sound absorbtion coefficients using these two methods, and then we compared the results of the sound absorbtion coefficients to look into the difference of results between reverberation room method and impedance tube method. Also we compared the results of the sound absorbtion coefficients with respect to the size of sample and the volume of reverberation room. From the experiment, we could see that the sound absorbtion coefficients are measured equally for different sample size. But the sound absorbtion coefficients are measured differently according to test methods and test conditions.

환형 공명기가 설치된 소음기 설계 및 성능 시험

김봉기(Kim, Bong-Ki),김상렬(Kim, Sang-Ryul),이성현(Lee, Seong-Hyun),이종화(Lee, Jong-Hwa),이해성(Lee, Hae-Seong) 한국소음진동공학회 2011 한국소음진동공학회 논문집 Vol.21 No.4

In this study, ring-shaped acoustic resonators were proposed to be installed in a silencer to increase the acoustic performance of silencer in the low-frequency range. Evaluation of noise reduction performance of acoustic resonator arrays was carried out by measuring the random-incidence absorption coefficient. It was found that the absorption coefficient of resonator array was measured up to 1 at 125 Hz of 1/3-octave band center frequency. Insertion losses of silencers with ring-shaped acoustic resonator arrays were measured based on ISO 7235. The results were shown that the ring-shaped resonator could increase the insertion loss up to 13 dB without flow, whereas 7 dB when flow speed reached 15 m/s. As increasing the flow speed above 15 m/s, the effect of acoustic resonator decreased due to the effect of nonlinear air damping of the resonator. It was also found that the increment of pressure drop by the presence of resonator arrays was about 9 % at flow speed of 25 m/s.

실내장식용 섬유소재의 흡음성에 관한 연구

최인려 ( In Ryu Choi ),방혜경 ( Hey Kyong Bang ) 복식문화학회 2012 服飾文化硏究 Vol.20 No.4

The purpose of this study is to help to prevent daily noises by measuring the noise absorption coefficient of the non-woven fabrics and wallpapers which are commonly used in lining and noise absorption coefficient of lining curtain, Seven types of fiber materials for the interior decoration, one non-woven fabric for the wallpaper linings, and two types of textiles for curtain linings are used as the experimental materials in this study. The noise absorption coefficient of the noise absorbents were measured by using impedance tube, And the thermal transmittance were measured by using thermal transmittance Lester. The results of this study are as follows; Observing the noise absorption efficiency of each experimental materials, the combination of fiber materials and linings, the noise absorption efficiency of cotton, polyester and silk were similar and for the experimental materials of flax, rayon, acrylic and nylon were resulted the similar noise absorption efficiency. The result of combination of fiber material and black fabric was highest among the combined linings. For the combination of fiber material and non-woven fabric, double layers of non-woven fabric resulted slightly higher noise absorption coefficient result than single layer of non-woven fabric. The thermal transmittance and the sound absorbents of experimental materials were affected by the thickness, density and layer of air of the experimental materials.

테프론 막 재료의 흡음특성 및 적용효과 연구

정정호(Jeong, Jeong-Ho),손장열(Shon, Jang-Ryul),김정중(Kim, Jung-Joong) 한국소음진동공학회 2007 한국소음진동공학회 논문집 Vol.17 No.4

Following the 2002 World-Cup held in Korea, studies have been actively conducted on plans to utilize all-weather stadiums of fine figures, where large-scale spaces are available for various utilizations. In Japan, dome-type stadiums have been built and are utilizing across the whole nation not only for sports events but also variety of other large-scale events. PTFE(poly tetra fluoro ethylene) is one of the membrane material mainly used for the outer ceiling surface of membrane structures. However, there has not been enough research on the acoustical properties of PTFE membrane material which has been widely used in the multi-purpose stadiums. In this study, air permeability values and sound absorption coefficient of PTFE membrane materials were measured and evaluated in the gymnasium. From the results of measurements of sound absorption coefficient and air permeability of inner membrane materials, it was found that the sound absorption coefficient was good in the air permeability range of $5{\sim}15\;cc/cm^2/s$. Also the relation ship between air permeability and sound absorption coefficient was very high and the sound absorption coefficient was the highest in the range of $6{\sim}9\;cc/cm^2/s$. Secondly, an analysis on the measurements sound absorption characteristics of inner membrane material reveals that the overall sound absorption coefficient was stabilized(higher than 0.5 throughout the whole frequency bands) when the air space behind the membrane material was deeper than 600 mm. When PTFE sound absorptive membrane material was installed in the ceiling of gymnasium, it was confirmed that sound absorptive membrane material can reduce reverberation and increase speech intelligibility in the gymnasium.