• Journal of Industrial Technology
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• v.17
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• pp.205-211
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• 1997

The problem of deteriorated highway concrete slab is very serious all over the world. Before making any decision on repair work, reliable non-destructive evaluation is necessary. One of the dependable methods is to evaluate the in-situ stiffness of the slab by means of obtaining the natural frequency. By comparing the in-situ stiffness with the one obtained at the design stage, the degree of damage can be estimated rather accurately. In this paper, the numerical modeling of vibration analysis to three span continuous reinforced concrete bridge with elastic intermediate support is presented.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.10a
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• pp.276-277
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• 2012

This study was carried out in the laboratory of the reverberation. A total of six specimens were fabricated depending on the thickness and strength. Floor impact sound insulation performance was measured in 1/3 octave band center frequency. The results of this study are as follows. Although some differences in the frequency band, the result of evaluating the weight impact sound blocking performance as the thickness increases, the floor impact sound insulation performance is improved. In addition, to increase the strength of the slab, even if the block impact sound performance is improved.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.506-511
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• 2000

The aim of this study is to suggest a fundamental data to improve the sound insulation performance of floor. To achieve the aim of this study, 8 types of sound-absorbing and sound insulation materials were installed under the slab, and the floor systems were compared to the general floor system which was composed of slab, timber frame, gypsum board and wallpaper.

• Computational Structural Engineering
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• v.7 no.2
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• pp.77-87
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• 1994

Vibrational analysis of slab tracks for HSR(High Speed Rail) is performed in order to find dynamic characteristics and to control noise and vibration for the tracks. Wheel-rail interactive force is included in the analysis by modelling the vehicle and track as an unsprung mass and elastically-supported-double-beam respectively, and both are assumed to be connected by the Hertzian spring. From this study, it has been found that vibration in the track and the force transmitted to the infrastructure could be reduced by controlling elasticity, mass and stiffness of the track supporting system appropriately.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.94-98
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• 2012

연구소로 사용될 FRF 및 Dynamic Stiffness에 대한 평가를 진행하였다. 동강성을 평가하여 정밀설비의 사용 가능여부를 파악하고 Slab의 위치에 따른 진동응답함수를 평가하여 정밀설비에 대한 설치위치의 참고자료로 활용하고자 한다. 또한, 추후 진동원 설비에 대한 방진대책 선정 자료로 사용하고자 한다.

• Journal of the Society of Disaster Information
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• v.10 no.2
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• pp.312-318
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• 2014

Recent building structures are superior in its ability but they are light weight and long span, and so have problems of vibration. In general, the serviceability of RC slabs was known to be good against vibration because of its hardness. However, recent high-rise apartment slabs are mostly light and long, the serviceability of RC slabs due to vibration could be a problem. In this paper, a basic investigation about vibration problems of RC slabs was performed. Basic information and its influence on vibrations of RC slabs were revealed. Also, its serviceability against vibration was examined. Many tests were conducted for natural frequency of building, for example load of two persons walking and one person leaping etc.

• Journal of Korean Association for Spatial Structures
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• v.9 no.4
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• pp.5-10
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• 2009

• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.1
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• pp.70-81
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• 2024

In this study, Tridimensional Hybrid Isolation System(THIS) was proposed as a vibration isolator for traffic loads, combining vertical and horizontal isolation systems. Its efficacy in improving serviceability for vertical vibration was analytically evaluated. Firstly, for the analysis, the major vibration modes of the existing apartment were identified through eigenvalue analysis for the system and pulse response analysis for the bedroom slab using commercial structural analysis software. Subsequently, a 16-story model with horizontal, vertical and rotational degrees of freedom for each slab was numerically organized to represent the achieved modes. The dynamic analysis for the measured acceleration from an adjacent ground to high-speed railway was performed by state-space equations with the stiffness and damping ratio of THIS as variables. The result indicated that as the vertical period ratio increased, the threshold period ratio where the slab response started to be suppressed varied. Specifically, when the period ratio is greater than or equal to 5, the acceleration levels of all slabs decreased to approximately 70% or less compared to the non-isolated condition. On the other hand, it was ascertained that the influence of damping ratios on the response control of THIS is inconsequential in the analysis. Finally, the improvement in vertical vibration performance of THIS was evaluated according to design guidelines for floor vibration of AIJ, SCI and AISC. It was confirmed that, after the application of THIS, the residential performance criteria were met, whereas the non-isolated structure failed to satisfy them.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.22 no.5
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• pp.421-428
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• 2009

In this study, an equivalent plate element model has been developed for an efficient vibration analysis of a biaxial hollow slab. To this end, equivalent mass and stiffness of equivalent plate element models corresponding to solid element models of example biaxial hollow slabs were calculated. To verify the efficiency and accuracy of the equivalent plate element models, structural analyses of example structures were performed. Analytical results showed that the natural frequencies of the equivalent plate element models were very close to those of the solid element models. Time history analyses of example biaxial hollow slabs subjected to walking load were conducted using the equivalent plate element models and the solid element models, and the results were compared. It could be seen based on the analytical results that the equivalent plate element model could provide very accurate results compared to the solid element model with significantly reduced analysis time.