• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.521-526
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• 2004

In order to evaluate the effect of blasting vibration in buildings and it's resident located around blasting construction field in urban area, blasting vibration characteristics were measured the vibration level, vibration velocity. The 250g and 750g of charged powder were used at the apartment and at the ground, respectively. In the measurement of the ground, Z(perpendicularity) axis was the highest value in vibration level, but vertical axis was the highest value at 25m point and longitudinal axis was the highest value at 50m point in vibration velocity. The amount of measurement was high value when measuring point is higher than blasting source, while that of measurement was low value when measuring point is lower than blasting source. In the measurement of the apartment, 2 axis was the highest value in vibration level, but in vibration velocity transverse axis was the highest value at ground, was vertical axis at 1st floor, was longitudinal axis at 3rd floor and was vertical and longitudinal axis at 5th floor. The vibration level and the vibration velocity of 50m point showed higher correlation value than 25m point at the ground, but those of 25m point showed higher correlation value than 50m point at the apartment.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2009년도 춘계학술대회 논문집
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• pp.662-667
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• 2009

In this study, the serviceability of Waffle shaped(WAS) and Double-Tee(DT) precast concrete slabs was evaluated and compared based on the vertical acceleration magnitude induced by walking and heel drop loads. Tests were conducted for practical building structures (a shopping mall in Hanam) of which floor systems used WAS and DT slabs. Natural frequencies of the slabs were similar to those obtained by using analytical models. The measured acceleration level was evaluated by vertical floor acceleration criteria presented by ISO-2631, AIJ(1991, Japan), and a previous study regarding floor vibration limit. Test results showed that both WAS and DT slabs satisfied all the criteria and the maximum acceleration level of WAS slabs was lower than that of DT slabs.

• 한국재난정보학회 논문집
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• 제8권2호
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• pp.197-203
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• 2012

최근 환경 공해 저감에 대한 사회적 요구가 높아짐에 따라 구조물의 방음, 방진 설계가 더욱 중요해지고 있다. 이 논문에서는 최근 개발된 수직형 면진장치의 기본 개념 및 성능 확인 실험 결과를 제시하였다. 개발된 면진장치는 PTFE 재질 마찰면의 마찰작용을 이용하여 수직방향의 진동을 감쇠시키고 수평 및 수직으로 배치된 폴리우레탄 소재의 스프링을 통하여 복원력을 제공하는 구조이다. 성능확인 실험은 하중 재하 속도에 변화에 따른 성능 변화추이를 파악하기 위한 실험과 고정하중이 적용된 후 발생되는 진동하중 작용 시 가정된 하중-변위 특성을 확인하기 위한 실험으로 구성하였다.

• Structural Engineering and Mechanics
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• 제55권2호
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• pp.413-434
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• 2015

The vibrations caused by metro operation propagate through surrounding soil, further induce secondary vibrations of the nearby underground structures and adjacent buildings. In order to investigate the effects of vibrations caused by metro on use performance of buildings, vibration experiment of Chengdu museum was carried out firstly. Then, the coupling tunnel-soil-structure finite element model was established with software ANSYS detailedly, providing a useful tool for investigating the vibration performances of structures. Furthermore, the dynamic responses and vibration predictions of museum building were obtained respectively by the whole process time-domain analysis and frequency-domain analysis, which were compared with the vibration reference values of museum. Quantitative analyses of the museum building performance were carried out, and the possible tendency and changing laws of vibration level with floors were proposed. Finally, the related vibration isolation measures were compared and discussed. The tests and analysis results show that: The vertical vibration responses almost increased with the increasing of building floors, while weak floors existed for the curve of horizontal vibration; The vertical vibrations were larger than the horizontal vibrations, indicating the vibration performances of building caused by metro were characterized with vertical vibrations; The frequencies of the museum corresponding to the peak vibration levels were around 6~17Hz; The damping effect of structure with 33m-span cantilever on vertical vibration was obvious, however, the damping effect of structure with foundation vibration isolators was not obvious.

• Smart Structures and Systems
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• 제33권6호
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• pp.415-430
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• 2024

To control vertical and lateral compound vibration simultaneously using an integrated smart controller, passive tuned mass damper (TMD) and tuned liquid damper (TLD) are updated and combined to an adaptive-passive TMD-TLD (AP-TMD-TLD) system. As for the vertical AP-TMD part on top of the vertical spring, it can retune itself through varying the level of liquid in the tank to adjust its mass, while the lateral AP-TLD part at the bottom of the vertical spring can retune itself by changing the level of liquid. Further, for multimodal response control, the multiple AP-TMD-TLD (MAP-TMD-TLD) system is proposed as well. Each AP-TMD-TLD in the system can identify the structural vertical and lateral modal frequencies through the wavelet-transform (WT) based algorithm and retune its vertical and lateral natural frequencies both through adjusting the level of liquid in the AP-TMD and AP-TLD parts respectively. A cantilever cable-stayed landscape bridge which is sensitive to both human-induced and wind-induced vibrations is presented as a case study. For comparison, initial parameters of MAP-TMD-TLD are mistuned. Results show that the presented system can retune its vertical and lateral frequencies precisely, while the retuned system has a better bi-directional compound control effect than the mistuned system before the retuning operation and can improve the serviceability significantly.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 추계학술대회 논문집
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• pp.602-606
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• 2011

In this study, operational vibration experiment and analysis have been conducted for the 4-blade small vertical-axis wind turbine (VAWT) including the effect of tower elastic behavior. Computational structural dynamics analysis method is applied to obtain Campbell diagram for the VAWT with elastic tower. An open type wind-tunnel is used to change and keep the wind velocity during the ground test. Equivalent reduced elastic tower is supported to the VAWT so that the elastic stiffness effect of the tower can be reflected to the present vibration experiment. Various excitation sources with aerodynamic forces are considered and the dominant operating vibration phenomena are physically investigated in detail.

• 전기학회논문지
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• 제58권3호
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• pp.566-572
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• 2009

This paper has studied breakage possibility of glass insulators by resonance and accelerated deterioration through the comparison of the natural vibration and on site vibration. The natural frequencies of the strut tube glass insulator was measured within a range of less than 1kHz. In the on site vibration, the largest frequency that was imposed on strut tube glass insulators was 80Hz with 1.13g of vertical vibration in the viaduct section, the largest vertical vibration (0.38g) was detected at 103Hz in the open route section. When site vibration and natural vibration of strut tube glass insulators were compared in terms of characteristics, the resonance frequency was not the same. In both the viaduct and open route sections, it seems that the impact by vertical vibration in strut tube glass insulators is large. It's very unlikely that glass insulators were damaged by fatigue accumulation of vibration since the possibility of damage by resonance was very low in consideration of the characteristics of natural vibration and site vibration of glass insulators. In addition, no damage was detected in the accelerated deterioration test.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 춘계학술대회 논문집
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• pp.218-223
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• 2011

Seated human subjects have been exposed to vertical vibration so as to investigate six-axis biodynamic response. Sixteen males were exposed to random vertical vibration in the frequency range(3~40Hz) at one vibration magnitude(0.224m/$s^2$ r.m.s.). Forces were measured in the vertical, fore-and-aft, lateral, roll, pitch and yaw direction on the seat. The median of cross-axis apparent mass magnitude in the fore-and-aft direction could reach up to 20% of the apparent mass magnitude at resonance frequency. And the median of apparent eccentric mass magnitude in the roll direction could reach up to 15% of the apparent eccentric mass magnitude in the pitch direction at resonance frequency. But cross-axis apparent mass in the lateral direction and apparent eccentric mass in the yaw direction showed very small.

• 소음진동
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• 제9권5호
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• pp.928-935
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• 1999

Vertical pumps are widely used owing to the fact that they occupy small floor space. In this type of pumps, however, the vibrational problems are very important, since, in many cases, they have less stiffness in comparison with lateral pumps. This study presents a simple solution method for calculating the natural frequencies and modes of vertical pumps. In this study, a mode of a vertical pump was developed and the nondimensional parameters for the vibrational characteristics of it were determined. Added mass was calculated for the effects of water and the transfer matrix method was used.

• Geomechanics and Engineering
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• 제5권3호
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• pp.223-240
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• 2013

In the present study an attempt was made to predict the complex nonlinear parameters of the soil-pile system subjected to the vertical vibration of rotating machines. A three dimensional (3D) finite element (FE) model was developed to predict the nonlinear dynamic response of full-scale pile foundation in a layered soil medium using ABAQUS/CAE. The frequency amplitude responses for different eccentric moments obtained from the FE analysis were compared with the vertical vibration test results of the full-scale single pile. It was found that the predicted resonant frequency and amplitude of pile obtained from 3D FE analysis were within a reasonable range of the vertical vibration test results. The variation of the soil-pile separation lengths were determined using FE analysis for different eccentric moments. The Novak's continuum approach was also used to predict the nonlinear behaviour of soil-pile system. The continuum approach was found to be useful for the prediction of the nonlinear frequency-amplitude response of full-scale pile after introducing the proper boundary zone parameters and soil-pile separation lengths.