• Journal of Korean Association for Spatial Structures
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• v.16 no.3
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• pp.107-115
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• 2016

In recent years, an outrigger damper system has been proposed to reduce dynamic responses of tall buildings. However, a study on outrigger damper system is still in its early stages. In this study, time history analysis was performed to investigate the dynamic response control performance of outrigger damper. To do this, a actual scale 3-dimensional tall building model with outrigger damper system has been developed. El Centro earthquake was applied as an earthquake excitation. The control performance of the outrigger damper system was evaluated by varying stiffness and damping values. Analysis results, on the top floor displacement response to the earthquake load, was greatly effected by damping value. And acceleration response greatly was effected by stiffness value of damper system. Therefore, it is necessary to select that proper stiffness and damping values of the outrigger damper system.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.6
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• pp.483-492
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• 2014

Uncomfortable feelings of occupants by indoor floor impact noise in a residential building are not accurately represented by the floor impact noise from a standard impact source. It is due to the characteristics of standard impact sources, which are different from the impact forces produced by occupants. It varies significantly by impact source, and it is not easy to be replicated for testing. As a result, the indoor floor impact noise under different acoustic conditions cannot be directly compared. Using frequency response function(FRF), which represents the input-output relationships of a dynamic system, it is possible to examine the characteristics of the system. Especially, FRF can predict the response of a linear dynamic system subjected to various excitation. To determine the relationship between impact force and the corresponding response of dynamic system in residential building, the acceleration response of a concrete slab and the floor impact noise in the living room, produced by bang-machine and rubber-ball excitation, were measured. The test results are compared to the estimates based on FRF and impact force spectrum.

• Wind and Structures
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• v.7 no.2
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• pp.89-106
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• 2004

The response of tall buildings to gust buffeting is usually evaluated assuming that the structural damping is of a viscous nature. In addition, when dampers are incorporated in the design to mitigate the response, their effect is allowed for increasing the building modal damping ratios by a quantity corresponding to the additional energy dissipation arising from the presence of the devices. Even though straightforward, this procedure has some degree of inaccuracy due to the existence of a memory effect, associated with the damping mechanism, which is neglected by a viscous model. In this paper a more realistic viscoelastic model is used to evaluate the response to gust buffeting of tall buildings provided with energy dissipation devices. Both cases of viscous and hysteretic inherent damping are considered, while for the dampers a generic viscoelastic behaviour is assumed. The Laguerre Polynomial Approximation is used to write the equations of motion and find the frequency response functions. The procedure is applied to a 25-story building to quantify the memory effects, and the inaccuracy arising when the latter is neglected.

• Structural Engineering and Mechanics
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• v.4 no.5
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• pp.497-511
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• 1996

The equivalent static force procedure and the response spectrum analysis method are widely used for seismic analyses of multi-story buildings. The equivalent static force procedure is one of the most simple but less accurate method in predicting possible seismic response of a structure. The response spectrum analysis method provides more accurate results while it takes much longer computational time. In the response spectrum method, dynamic response of a multi-story building is obtained by combining modal responses through a proper procedure such as SRSS or CQC method. Since all of the analysis results are expressed in absolute values, structural engineers have difficulties to combine them with the results obtained from the static analysis. Design automation is interrupted at this stage because of the difficulty in the decision of the most critical design load. Pseudo-dynamic analysis method proposed in this study provides more accurate seismic analysis results than those of the equivalent static force procedure since the dynamic characteristics of a structure is considered. And the proposed method has an advantage in combination of the analysis results due to gravity loads and seismic loads since the direction of the forces can be considered.

• Wind and Structures
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• v.37 no.1
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• pp.1-13
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• 2023

Due to the irregular shape and the deviation of stiffness center and gravity center, buildings always suffer from complex surface load and vibration response under wind action. This study is dedicated to analyze the surface wind load and wind-induced response of an irregular building, and to discuss the possibility of top swimming pool as a TLD to diminish wind-induced vibration of the structure. Wind tunnel test was carried out on a hotel with irregular shape to analyze the wind load and structural response under 8 wind incident angles. Then a precise numerical model was established and calibrated through experimental results. The top swimming pool was designed according to the principle of frequency modulation, and equations of motion of the control system were derived theoretically. Finally, the wind induced response of the structure controlled by the pool was calculated numerically. The results show that both of wind loads and wind-induced responses of the structure are significantly different with wind incident angle varies, and the across-wind response is nonnegligible. The top swimming pool has acceptable damping effect, and can be designed as TLD to mitigate wind response.

• Earthquakes and Structures
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• v.25 no.2
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• pp.135-148
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• 2023

The structure-soil-structure interaction (SSSI) effect in adjacent structures may affect the liquefaction-induced damage of shallow foundation structures. The existing studies only analysed the independent effects on the structural dynamic response but ignored the coupling effect of height difference and distance of adjacent structures (F) on liquefied foundations on the dynamic response. Therefore, this paper adopts finite element and finite difference coupled dynamic analysis method to discuss the effect of the F on the seismic response of shallow foundation structures. The results show that the effect of the short structure on the acceleration response of the tall structure can be neglected as F increases when the height difference reaches 2 times the height of the short structure. The beneficial effect of SSSI on short structures is weakened under strong seismic excitations, and the effect of the increase of F on the settlement ratio gradually decreases, which causes a larger rotation hazard. When the distance is smaller than the foundation width, the short structure will exceed the rotation critical value and cause structural damage. When the distance is larger than the foundation width, the rotation angle is within the safe range (0.02 rad).

• Journal of Energy Engineering
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• v.26 no.4
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• pp.29-34
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• 2017

Factors of Zero-Energy Building are divided into active and passive factor. Passive factor means insulation, heat bridge of building like insulation, windows and doors, awning, outside etc. and active factor means energy output and efficiency coefficient. Energy output of active factor is achieved by new generating energy. This study anticipated how many effects will be produced when not new generating energy but Vehicle to Building; V2B, bi-directional charging and discharging technology, is applied to Zero-Energy Building. In new generating energy, power generation will be anticipated by geography and climate, but in V2B, several input variable like user's discharging intention and number of usable charger etc. should be considered. We can check how much V2B contribute to the Zero-Energy Building by anticipated results, and that results should be anticipated by using probabilitic method because there is few statistical data. This study anticipate change of charging and discharging pattern, based by Demand Response slot, by using monte carlo method among the probabilitic methods.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2002.10a
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• pp.513-520
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• 2002

This study is for seismic analysis of building structures with ambiguous modal direction This case is revealed symmetrical building structure or the structure that isn't coincided building axis with physical axis. Seismic analysis-time history analysis, response spectrum analysis and lateral force procedure-is carried out. It is concluded that analysis method for the structure with ambiguous modal direction don't suitable for lateral force procedure. It is recommended to use the CQC method for combining modal responses to the individual components and the SRSS rule for combining responses to the two horizontal components are of nearly equal intensities.

• Land and Housing Review
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• v.5 no.2
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• pp.107-114
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• 2014

Passive energy dissipation systems for seismic applications have been under development for a number of years with a rapid increase in implementations starting in the mid-1990s in many countries. A metallic hysteretic damper has most commonly been used for seismic protection of structures in domestic area because they present high energy-dissipation potential at relatively low cost and easy to install and maintain. This paper presents an analytical case study of the effectiveness of isotropic hysteretic metallic damper(IHMD) called Kagome as a passive dissipative device in reducing structural response during seismic excitation. An eighteen-story RC framed apartment building is studied with and without IHMD. Results demonstrate the feasibility of these techniques for seismic mitigation. The inclusion of supplemental passive energy dissipation devices in the form of IHMD proved to be a very effective method for significantly reducing the seismic response of the building investigated.

• Wind and Structures
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• v.6 no.1
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• pp.71-90
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• 2003

In recent years, high-strength, light-weight materials have been widely used in the construction of high-rise buildings. Such structures generally have flexible, low-damping characteristics. Consequently, wind-induced oscillation greatly affects the structural safety and the comfort of the building's occupants. In this research, wind tunnel experiments were carried out to study the wind-induced vibration of a building with a tuned liquid column damper (TLCD). Then, a model for predicting the aerodynamic response in the across-wind direction was generated. Finally, a computing procedure was developed for the analytical modeling of the structural oscillation in a building with a TLCD under the wind load. The model agrees substantially with the experimental results. Therefore, it may be used to accurately calculate the structural response. Results from this investigation show that the TLCD is more advantageous for reducing the across-wind vibration than the along-wind oscillation. When the across-wind aerodynamic effects are considered, the TLCD more effectively controls the aerodynamic response. Moreover, it is also more useful in suppressing the acceleration than the displacement in biaxial directions. As s result, TLCDs are effective devices for reducing the wind-induced vibration in buildings. Parametric studies have also been conducted to evaluate the effectiveness of the TLCD in suppressing the structural oscillation. This study may help engineers to more correctly predict the aerodynamic response of high-rise buildings as well as select the most appropriate TLCDs for reducing the structural vibration under the wind load. It may also improve the understanding of wind-structure interactions and wind resistant designs for high-rise buildings.