• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.499-504
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• 2004

The purpose of this study is to investigate a investigating of a floor-impact isolation system using damping materials in apartment buildings. The stiffness elastic modulus(k) by puls impact forces were calculated loss factor by Hilbert transforms. It is absolved that natural frequency was moved floor shock-absorbing materials and the impact force was reduced by floor panel. The slab was constructed by damping materials. As towards a result, the system showed inverse A 45dB by heavy weight-impact noise and inverse A 52dB by light-impact noise. High frequencies impact-noise can be reduced by upgrading naturial frequency of vibration and noise in the system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.255-260
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• 2003

The regulation for floor impact sound level is expected to be amended to 50㏈(L$\_$i, Fmax, AW/) and below in heavy-weight impact sound and 58㏈(L'$\_$n, AW/) and below in light-weight impact sound in Korea. The purpose of this paper is to analyze the influence factors of floor impact sound levels in apartments. The influence factors were air pressure of bang machine, height of microphones, data acquisition rate, etc. The air pressure range of bang machine were from 2.2 Pa to 2.6 Fa. Five microphones were installed at a height of 0.5m, 0.7m, 0.9m, 1.2m, 1.5m or 1.7m from floor level. The floor impact sound level was varied about 1-3㏈(L$\_$i, Fmax, AW/) in heavy-weight impact sound according to the influence factors.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.1044-1047
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• 2004

This aim of this study is is an experimental study to introduce the Reduction method of Floor Impact Sound in Apartment Houses by using Model Test, We are measured the floor impact sound in Rahamen and Apartment with Shear Wall and Post-tensioning. There is comparison between Rahmen Structure and Apartment with Shear Wall. The main results from this study are effective in reduction of heavt-weight The slab was constructed by rahamen structure. Heavy-weight can reduced by upgrading naturial frequency of floor impact sound in rahmen structure.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.592-597
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• 2002

The purpose of this study was to analyze the characteristics of a new heavy weight impactor, the Rubber Ball. Until now Bang-machine has been used to measure the heavy impact noise in accordance with JIS A 1418-1. However, various kinds of examination methods have been needed to make an objective observation of insulation capacity for floor impact noises. Two types of experiments were undertaken. First, the experiment about noise was carried out about an apartment building in actual living condition. Then. vibration noises from the impactors were analyzed. The results of this study were as follows : the result of experiment carried out with bonded area of bail was closer to practical experiment than that of non bonded area. In addition, the result about bonded area of ball was more similar to the result which is claimed by H. Tachibana than that about non bonded area. Moreover, it was found that Rubber Ball has more similar vibration characteristics to the real impact noise source than Bang-machine.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.5 s.98
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• pp.604-611
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• 2005

The relationship between floor impact sound and vibration has been studied by field measurements, and the vibration modal characteristics have been analyzed. Vibration levels impacted by a standard heavy-weight impact source have been predicted according to the main design parameters using finite element method. Experimental results show that the dominant frequencies of the heavy impact sounds range below 100 Hz and that they are coincident with natural frequencies of the concrete slab. In addition, simple 2-dimensional finite element models are proposed to substitute 2 types of 3-dimensional models of complicated floor structural slabs those by The analytical result shows that the natural frequencies from first to fifth mode well correspond to those by experiments with an error of less than $12\%$, and acceleration peak value iscoincident with an error of less than $2\%$. Using the finite element model. vibration levels areestimated according to the design Parameters, slab thickness, compressive strength, and as a result, the thickness is revealed as effective to increase natural frequencies by $20\~30\%$ and to reduce the vibration level by 3$\~$4 dB per 30 mm of extra thickness.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.6
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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.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.4 s.97
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• pp.465-473
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• 2005

The impact sounds, generated by the walking of people, the dropping of an object or the moving of furniture, can be a source of great annoyance in residential buildings. The characteristics and level of this impact noise depends on the object striking the floor, on the basic structure of the floor, and on the finish materials of floor. The focus of this paper is to investigate the amount of improvement impact sound pressure level according to the change of the composition method of ceiling and wall. For this purpose, we tested impact sound pressure level of several cases which is the inserting of mineral wool, the increase of the thickness of air layer, the using of anti-vibration rubber in ceiling and attach the mineral wool on wall in the Floor Impact Sound Test Building of KICT. The results show that the composition method of ceiling and wall is more effective in the reduction of light weight impact sound specially in 125Hz and 250Hz.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.261-264
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• 2004

Impact sounds, such as those created by footsteps, the dropping of an object or the moving of furniture, can be a source of great annoyance in residential buildings. The character and level of impact noise generated depends on the object striking the floor, on the basic structure of the floor, and on the floor covering. This study base on the evaluate of isolation performance of impact sound according to the installation of ceiling and wall. In this test, we measured the reduction of impact sound in the case of inserting absorption materials, increasing of the thickness of air layer and using anti-vibration rubber in ceiling, install of absorption materials in wall. The results of this study show that treatment of ceiling and wall have some reduction of the light weight impact sound and heavy weight impact sound.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.1
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• pp.8-15
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• 2020

In the present paper, as a way of reducing heavyweight impact sounds, in particular, among floor impact sounds which have come to the forefront as a social issue recently, a floor joist slab is proposed that is expected to bring an effect of reducing heavyweight impact sounds through a shift in the natural frequency by installing a floor joist on a flat-type slab to increase the rigidity of the floor slab, differently from the existing method that increases the thickness of floor slab, and the heavyweight impact sound characteristics depending on the floor joist height and interval are interpretively analyzed. As a result of the analysis, though a trend is shown where the sound pressure level decreases as the slab thickness of floor joist increases, and as no difference is shown when thickness is above a certain value, it is thought that there is a threshold for the effect of an increase in floor thickness on blockage of heavyweight impact sounds. Also, as an increase in floor rigidity resulting from an increase in the floor joist height and a decrease in the interval does not lead to a consistent increase in the performance of blocking heavyweight impact sounds, it is thought that a different floor joist height and interval should be applied to each type of house to expect optimum performance of blocking heavyweight impact sounds, and an increase of 100mm in the floor joist height or a decrease of about 100mm in the interval is expected to bring an effect of reducing heavyweight impact sounds by about 1dB to 2dB.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.397-398
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• 2013