• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.208-213
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• 2003

The purpose of this study is to review the use of a new standard impactor, the impact ball, in evaluating heavy-weight impact noises in reinforced concrete structures. A survey revealed that children running and jumping are the major heavy-weight impact sources in multi-story residential buildings. The noise from the impact ball was measured and psychoacoustically assessed. The relationship between the noise levels and the subjective responses was also investigated. Results showed that the noise from the impact ball is similar to the noise of children running and jumping. It was also found that the noise level of the impact ball is slightly higher than the noise level of a bang machine, although the impact ball has a lower impact force.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.451-456
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• 2004

In this study, evaluation was carried out for reduction method of floor impact noise through field test and the effective methods for heavy impact noise were proposed. As a field test, impact noise reduction materials such as EPP, EEPS, EVA, PE and so on, did not satisfied the recommandation value at the condition of 150mm thickness concrete slab. The evaluation results for those materials by 'inverse A curve' showed $53\sim55dB$ at heavy impact noise and $53\sim58dB$ at light impact noise. But, two methods proposed by authors were evaluated $47\sim50dB$ at heavy Impact noise and $54\sim58dB$ at light Impact noise on the similar concrete slab thickness.

• 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.

• 소음진동
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• 제5권1호
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• pp.95-106
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• 1995

Flow-induced vibration in heat exchanger (or fuel rod) in nuclar power plant can cause dynamic interactions between tubes and tube supports resulting in fretting-wear. To increase the reliability and design life of heat exchanger components, design criteria that establish acceptable limits of vibration and minimize fretting wear are necessary. The fretting-wear rate is dependent upon material combination, contact configuration, environmental conditions and tube-to tube support dynamic interaction. It is demostrated that the fretting -wear rate correlates well with tube-to-support contact force or work rate. The tube-to-support dynamic interaction, which consists of dynamic contact forces and tube motion, is used to relate single-span wear data to real heat exchanger configurations consisting of multi-span tube bundles. This paper describes the test facility to measure tube-to-support dynamic impact force and reports its dynamic characteristics through the four impact tests - a force transduces independent and external impact tests, central ring inside impact test and additional cylinder impact test. Through the tests the impact parameter change dependent upon the material difference of impacting ball is studied, and the impact parameters of Force Transducer Assembly components are measured. And also the dynamic behavior of Force Transducer Assembly is analyzed. The force measurement technique herein is shown to provide a reasonable measure of dynamic contact forces.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.950-955
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• 2002

ISO 140-11 specifies a method for measuring the acoustic properties of floor coverings from the view-point of reducing impact sound transmission. This test method is limited to the specification of procedures for the physical measurement of sound originating from an artificial impact source under laboratory conditions. In this study, ISO 140-11 was reviewed to applicable to domestic floor coverings installed on lightweight floors.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.226-229
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• 2001

Recently the impact sound insulation performance is regarded as one of the most import factors in determining the quality of housing environment. In order to reduce the impact sound level transmitted through the floors and structures, establishing the standard level of impact sound insulation performance is needed. In this consideration, The effecting facts for the standard insulation level is reviewed.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.350.2-350
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• 2002

The purpose of this study was to present the possible use of a new standard impactor, the rubber ball (so-called, impact ball), and to assess its evaluation method as fur heavy-weight impact in multi-story residential buildings. Several experiments were carried out to investigate the effect of the impactor on noise propagation in reinforced concrete buildings. Then, the noise from the impact ball was psychoacoustically evaluated. (omitted)

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.392.2-392
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• 2002

ISO 140-11 specifies a method for measuring the acoustic properties of floor coverings from the view-point of reducing impact sound transmission. This test method is limited to the specification of procedures for the Physical measurement of sound originating from an artificial impact source under laboratory conditions. In this study, ISO 140-11 was reviewed to applicable to domestic floor coverings installed on lightweight floors.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1998년도 창립기념 춘계학술대회 논문집
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• pp.287-290
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• 1998

Wheel impact due to the joint discontinuity is a major source of uncomfortable vibration in the railway vehicles. Since the impact signal is measured using sensors attached to the bogie and its energy content is small compared to the other vibrations from the machineries such as motors and gear systems, the seperation of the impact signal is generally difficult. In this study a technique using an evolutionary spectrum is proposed in order to estimate the impact signal due to the rail joint discontinuity.

• 환경영향평가
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• 제21권2호
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• pp.289-296
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• 2012

The shock vibration such as machine vibration, blasting vibration etc. has effect on nearby structure as well as human body. The purpose of this study is to predict allowable limit distance of vibration about human body. First of all, vibration velocity such as PPV, PVS was measured by shock vibration experiment, and vibration level was calculated by conversion formula of vibration velocity. And then, allowable limit distance was analyzed by converted vibration level. The results are as follows : Firstly, the correlation coefficient of converted vibration level was over R=0.94, and vibration level caused by PVS was usually represented to high curve line. Secondly, the cross point of vibration level between ground and concrete condition was represented to 66.68dB(V), and allowable limit distance was represented to difference over three times when vibration regulation was raised from 65dB(V) to 80dB(V).