• Journal of the Earthquake Engineering Society of Korea
• /
• v.7 no.3
• /
• pp.1-7
• /
• 2003

Excitation and system identification are carried out for a full-scale five-story structure to obtain fundamental data which will be used for the design of viscoelastic dampers, The hybrid mass driver(HMD) installed on the fifth floor was employed as external exciter to provide excitation for the building, Each floor response was measured and processed to find out where and how the viscoelastic dampers are located and designed. The sine-sweep and white noise loadings were applied to the structure by the HMD to obtain dynamic characteristics such as natural frequencies, damping ratios, and modes, The identified building was experimentally investigated again with the designed viscoelastic dampers installed at inter-stories to obtain the response behavior in the companion paper.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.43 no.9
• /
• pp.773-780
• /
• 2015

In this paper, the structural integrity for a cylindrical vehicle in subsonic environments is verified. In order to confirm static structural safety for the cylindrical vehicle in extreme maneuver condition, the structure analysis and full-scale static structure test are carried out. The commercial finite element codes, MSC. Patran/Nastran is used for numerical simulation. The full-scale static structure test equipment consists of the counterbalance system, loading system and data acquisition system. Besides, the dynamic characteristics for the cylindrical vehicle are reviewed by performing an impact hammer test.

• International Journal of High-Rise Buildings
• /
• v.10 no.2
• /
• pp.85-92
• /
• 2021

Dynamic vibration absorbers (DVAs) in the form of tuned sloshing dampers (TSDs) and tuned mass dampers (TMDs) are commonly used to reduce the wind-induced motion of high-rise buildings. Full-scale performance of structure-DVA systems must be evaluated during the DVA commissioning process using structural monitoring data. While the random decrement technique (RDT) is sometimes employed to evaluate the DVA performance, it is shown to have no theoretical justification for application to structure-DVA systems, and to produce erroneous results. Subsequently, several practical methods with a sound theoretical basis are presented and illustrated using simulated and real-world data. By monitoring the responses of the structure and DVA simultaneously, it is possible to directly measure the effective damping of the system or perform system identification from which the DVA performance can be evaluated.

• Nuclear Engineering and Technology
• /
• v.54 no.6
• /
• pp.2120-2134
• /
• 2022

A hypothetical core destructive accident (HCDA) has received widespread attention as one of the most serious accidents in sodium-cooled fast reactors. This study combined recent advantages in numerical methods to realize realistic modeling of the complex fluid-structure interactions during HCDAs in a full-scale sodium-cooled fast reactor. The multi-material arbitrary Lagrangian-Eulerian method is used to describe the fluid-structure interactions inside the container. Both the structural deformations and plug rises occurring during HCDAs are evaluated. Two levels of expansion energy are considered with two different reactor models. The simulation results show that the container remains intact during an accident with small deformations. The plug on the top of the container rises to an acceptable level after the sealing between the it and its support is destroyed. The methodology established in this study provides a reliable approach for evaluating the safety feature of a container design.

• Proceedings of the KSR Conference
• /
• 2002.10a
• /
• pp.54-59
• /
• 2002

In general, the aluminum extrusions are used to the light construction of the high speed rail vehicle structures. However, the research works ok the crashworthy design of the high speed rail vehicle structures are not published sufficiently because the crash test of high speed rail vehicle structures costs high and is complicated. So, a method that can predict crash characteristics of a large size structure like a high speed tail vehicle should be suggested. In this study, the scale model studies are performed to predict the impact energy absorption characteristics of full scale model. In the first place, we verified the theory of scale law using FE-simulation from the crashworthiness point of view. Secondly, we performed the crush test using scale model, made of aluminum sub structure. As a result, we could predict the crash characteristics using scale model by 10∼20% error.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2001.04a
• /
• pp.461-467
• /
• 2001

Shaking table tests were performed with full scale models of stone parapet on the ancient rampart. The objectives of these tests are to study the seismic behavior of the parapet and to obtain quantitative estimation of the intensities of historical earthquakes. Two test models were made based on the structure of the parapet remnant of a mountain fortress in Bukhan-San located in Seoul. Two types of infilling material are considered. The responses to models were tested subjected to three kinds of input motion.

• Wind and Structures
• /
• v.32 no.2
• /
• pp.143-159
• /
• 2021

The 246.8-m-tall Beijing Olympic Tower (BOT) is a new landmark in Beijing City, China. Its unique architectural style with five sub-towers and a large tower crown gives rise to complex dynamic characteristics. Thus, it is wind-sensitive, and a double-stage pendulum tuned mass damper (DPTMD) has been installed for vibration mitigation. In this study, a finite-element analysis of the wind-induced responses of the tower based on full-scale measurement results was performed. First, the structure of the BOT and the full-scale measurement are introduced. According to the measured dynamic characteristics of the BOT, such as the natural frequencies, modal shapes, and damping ratios, an accurate finite-element model (FEM) was established and updated. On the basis of wind measurements, as well as wind-tunnel test results, the wind load on the model was calculated. Then, the wind-induced responses of the BOT with the DPTMD were obtained and compared with the measured responses to assess the numerical wind-induced response analysis method. Finally, the wind-induced serviceability of the BOT was evaluated according to the field measurement results for the wind-induced response and was found to be satisfactory for human comfort.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2002.11a
• /
• pp.368.1-368
• /
• 2002

System Identification is carried out for a full scale five-story holing to design a vibration controller design. Dynamic characteristics such as natural frequencies, damping ratios, and modes are obtained from the input/output informal ion by both sine-sweet method and white noise method. The active mass driver installed on the third floor is applied as external loading to move the building and each floor acceleration is measured and processed for the system identification. (omitted)

• Wind and Structures
• /
• v.4 no.2
• /
• pp.131-146
• /
• 2001

A full-scale synchronized data acquisition system was set up on the roof of the experimental building at the Texas Tech University Wind Engineering Research Field Laboratory to simultaneously collect approaching wind data, conical vortex images, and roof corner suction pressure data. One-second conditional sampling technique has been applied in the data analysis, which makes it possible to separately evaluate the influencing effects of the horizontal wind angle of attack, ${\theta}$, and the vertical wind angle of attack, ${\varphi}$. Results show a clear cause-and-effect relationship between the incident wind, conical vortices, and the induced roof-corner high-suction pressures. The horizontal wind angle of attack, ${\theta}$, is shown to be the most significant factor in influencing the overall vortex structure and the suction pressures beneath. It is further revealed that the vertical wind angle of attack, ${\varphi}$, plays a critical role in generating the instantaneous peak suction pressures near the roof corner.

• Journal of KSNVE
• /
• v.8 no.4
• /
• pp.700-705
• /
• 1998

Recent past work has demonstrated that hydraulic semiactive vibration absorbers hold the promise of providing an ideal means of mitigating structural vibration. This paper examines a factor that must be treated when designing a hydraulic semiactive vibration absorber for application to a full scale structure; fluid compressibility. An expanded and consistent dynamic model of the flow process is first established. A simple feedback control is then tested on a single degree of freedom laboratory structure to verify the findings.