• 한국소음진동공학회논문집
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• 제16권9호
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• pp.949-957
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• 2006

In this Paper, reduction of noise and vibration in ship cabins by using floating floor is studied. Two theoretical models are presented and predicted insertion losses of floating floor are compared to experimental results, where measurements have been done in mock-up built for simulating typical ship cabin structures. In ships, mineral wool is usually used as the impact absorbing materials. The first model (M-S-Plate Model) is that upper plate and mineral wool are assumed as a one-dimensional mass-spring system, which is in turn attached to the simply supported elastic floor. The second model (Wave-Plate Model) is that mineral wool is assumed as an elastic medium for wave propagation. The comparisons show that M-S-Plate model is in good agreement with experimental results when density of mineral wool is 140K, and fiber direction is horizontal. For higher density and vertical fiber direction, Wave-Plate model shows good agreements with measurements. It is found that including the elastic behavior of the floor is essential in improving accuracy of the prediction for low frequency ranges below $100{sim}200Hz$.

• Smart Structures and Systems
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• 제23권5호
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• pp.467-478
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• 2019

Composite floor structures formed by continuous slab panels may be susceptible to excessive vibrations, even when properly designed in terms of ultimate limit state criteria. This is due to the inherent vibration characteristics of continuous floor slabs composed by precast orthotropic reinforced concrete panels supported by steel beams. These floor structures display close spaced multimode vibration frequencies and this dynamic characteristic results in a non-trivial vibration problem. Structural stiffening and/or insertion of struts between floors are the usual tentative solution applied to existing vibrating floor structures. Such structural alterations are in general expensive and unsuitable. In this paper, this vibration problem is analyzed on the basis of results obtained from experimental measurements in typical composite floors and their theoretical counterpart obtained with computational modeling simulations. A passive control system composed by multiple synchronized dynamic attenuators (MSDA) was designed and installed in these floor structures and its efficiency was evaluated both experimentally and through numerical simulations. The results obtained from experimental tests of the continuous slab panels under human walking dynamic action proved the effectiveness of this control system in reducing vibrations amplitudes.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.97-102
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• 2004

The Characteristics of noise and vibration by heavy-weight floor impact sound was studied. Resonance frequency increased a little in structures that use damping material in living room and bedroom, and acceleration waves length that respond became short, and displayed aspect that oscillation level decreases. Result that measure sound pressure level, structure that compare and applies damping materials with structure that apply the resilient materials from 63Hz lower part that impact energy is concentrated in energy spectrum of heavy-weight floor impact sound displayed result that sound pressure, level decreases remarkably. Therefore, according to use of damping materials, confirmed reduction effect of heavy-weight floor impact sound.

• 한국소음진동공학회논문집
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• 제13권6호
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• pp.415-422
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• 2003

In an apartment buildings, the floor Impact sound from upstairs has been regarded as a main source of noise causing discontentment among occupants. To set the optimum design for sound insulation, it is necessary to suggest the useful tools or technique that predict the floor impact sound. The purpose of this study is to suggest the supplementary formula(equation) and constant k considering vibration transmissibility in order to predict more precisely heavy floor impact sound by Impedance Method that have been briskly studied in Japan from comparing the measured values with the predicted values. The analyzed results had showed that if the damping material was glass wool or rubber, k=5 was proper and if the damping material was polystyrene foam, k>5 was desirable.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 춘계학술대회 논문집
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• pp.425-430
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• 2014

Floor coverings and Mats are for children are economical and has excellent workability, as well as they can reduce floor impact noise effective. "When these floorings contact to impact source, they are deformed and change impact force characteristics that strikes floor structure. It is important to measure the impact force spectrum of floorings in order to evaluate reduction of floor impact noise for floorings. In experimental test of floor impact noise and impact force for 14 PVC vinyl floor coverings and 16 mats for children, we confirmed that the impact force spectrum directly related to the floor impact noise spectrum.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.419-422
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• 2014

Floor impact sound level is affected by various factors. This study was examined about impact sources and floor coverings influenced at floor impact sound. So this study wishes to get method to reduce sound pressure level of receiving room. Light-weight impact sound in mid frequency and Heavy-weight impact sound in low frequency was affected by floor coverings. Therefore, method to reduce floor impact sound level is to use proper floor coverings. Some coverings can amplify the heavy-weight impact sound in low frequency. Floor impact sound sources used measurement and analysis were standard heavy-impact source(Tapping, Bang, Ball) and living impact sources(Cleaner, Chair, Toy-car, Soccer ball). And Floor coverings used measurements were various thickness vinyl, laminate(or ply-wood) floor. Especially vinyl floor coverings were very effective method to reduce floor impact.

• 콘크리트학회논문집
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• 제17권5호
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• pp.687-694
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• 2005

건설 재료와 기술의 발달로 건축물이 장스팬화 ·경량화 되어 가고 있다. 이로 인해 건축물 바닥의 고유진동수(Frequency)와 감쇠비(damping ratio)가 감소함에 따라 거주자들의 바닥판의 수직진동에 대한 문제가 발생하고 있다 그러나 현행 사용성 기준은 바닥판의 최대 정적 처짐에 의해 결정하고 있다. 하지만 선행연구(Han et al., 2003)에서 현행 기준을 만족하는 바닥이 수직진동에 대한 사용성 기준을 만족하지 못하는 것을 볼 수 있다. 따라서 본 연구에서는 거주자들의 뒤꿈치 충격하중에 대한 수직진동 사용성 기준을 만족하는 바닥 두께를 제안하고자 하였다. 슬래브 재료의 특성과 뒤꿈치 충격하중 및 마감 고정하중의 불확실성을 고려하기 위해 Monte Carlo Simulation을 사용하여 확률적으로 접근하였다. 그 결과 4변 단순지지의 경우 두께가 스팬 길이의 $1/14\~1/17$에서, 4변 고정지지의 경우 스팬 길이의 $1/18\~1/25$인 경우에 초과 확률이$0\%$에 도달하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1998년도 춘계학술대회논문집; 용평리조트 타워콘도, 21-22 May 1998
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• pp.371-376
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• 1998

As the requirement of high-rise buildings in big cities increases, steel structural system becomes more popular in spite of the relatively higher material cost compared to that of the concrete structural system. Most of the steel structure adopts metal deck floor system because of the easiness in construction. However, the metal deck floor system has a weakness on vibration which became very important factor in office buildings, hotels and residential buildings as the more sensitive machines being used. Therefore, most, of the building codes in many countries restrict the natural frequency of the each floor should be higher than or equal to 15 Hz. Floor vibration of the KEM deck composite floor system which has been , developed recently from the engineers and scientists in Korea was measured. Also, the simplified analytical derivation of natural frequency for each floor was studied according to the measured natural frequency for each different boundary condition of the floor. As the length of the slab gets bigger, the natural frequency of the slab becomes lower even though the structural designer still considers it as a one-way slab.

• 한국소음진동공학회논문집
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• 제26권2호
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• pp.130-140
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• 2016

Floating floor is most commonly used at apartment houses in Korea for thermal insulation and reducing impact noise. But it in proven that the floating floor is not effective for reducing the floor impact noise in low frequency range. In most cases, impact sound pressure level under 63 Hz frequency band were actually increased by the resonance of resilient material, lightweight concrete and the finishing mortar installed on it. In this paper, an integrated floor system consist of 70 mm light weight concrete and 40 mm finishing mortar successively installed on the concrete slab was suggested to avoid the resonance. Integrated floor system increases total flexural stiffness and mass per unit area. The natural frequencies of first and second vibration mode were increased and acceleration response and floor impact sound level was decreased in all measurement range.

• KIEAE Journal
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• 제12권1호
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• pp.73-81
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• 2012

Floor impact sound has been most annoying for years among the noises which are produced in apartment. This study aims to analyze the improvement of floor impact sound by comparing the results of the test which was carried out for the wall slab type apartment and moment frame apartment, and also for the effect of advanced vibration isolation layer. Moment frame structure that main structure consists of column and slab has shown better performance for the heavyweight impact sound comparing with wall slab type structure which is general type in Korea. Stiffness of floor system was raised by reinforcing the stiffness of vibration isolation layer, and it was analyzed how much the floor impact sound performance was improved. The result showed that the reinforced floor had better performance than the existing floor system that uses lightweight porous concrete as vibration isolation material. In addition, a system used wire mesh in mortar showed improvement of floor impact sound than a system without wire mesh, and better performance for the frequency bands lower than 160 Hz which causes floor impact problem in wall slab type apartment.