• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2714-2719
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• 2007

HANARO, an open-tank-in-pool type research reactor of 30 MWth power in Korea, has been operating normally since its initial criticality in February, 1995. For the last about ten years, A cooling tower of a secondary cooling system has been operated normally in HANARO. Last year, the cooling tower has been overhauled for preservative maintenance including fills, eliminators, wood support, water distribution system, motors, driving shafts, gear reducers, basements, blades and etc. This paper describes the results of the overhaul. As results, it is confirmed that the cooling tower maintains a good operability through a filed test. And a cooling capability will be tested when a wet bulb temperature is maintained about 28 $^{\circ}C$ in summer and the reactor is operated with the full power.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2008.04a
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• pp.337-340
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• 2008

There were two transmission tower collapses due to Typhoon 'Maemi' in 2003. The reason that a collapse was happened was excessive wind load. One was buckled in the leg part and the other was buckled in the middle bracing part. To investigate a steel transmission tower failure mechanism, 2nd order nonlinear analysis should be performed. Considering the effect of initial imperfection and theresidual stress of angle section during nonlinear analysis, this study can estimate the ultimate strength and the ultimate behavior of the transmission tower.

• Journal of Korean Association for Spatial Structures
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• v.16 no.3
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• pp.67-78
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• 2016

Determining of the shape in the process of design for natural draught cooling tower is very important, because the shape of hyperbolic shell is respond sensitively to dynamic behavior of the whole cooling tower against wind load. In engineering practice, the geometric parameters have been determining based on the natural frequency. This study analyses influence of the tower shell geometric parameters on the structural behavior. For three representative models were selected, they were analyzed based on evaluation of damage by means of nonlinear FE-method. As a result, a hyperbolic rotational shell with the small radius overall was the lowest damage index induced by sufficient capacity of the stress redistribution and thus a wind-insensitive structure.

• Earthquakes and Structures
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• v.15 no.1
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• pp.97-111
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• 2018

Buildings featuring a transfer structure can be commonly found in metropolitan cities situated in regions of lower seismicity. A transfer structure can be in the form of a rigid plate or an array of deep girders positioned at the podium level of the building to support the tower structure of the building. The anomalous increase in the shear force demand on the tower walls above the podium is a major cause for concern. Design guidance on how to quantify these adverse effects is not available. In this paper a simplified method for quantifying the increase in the shear force demand on the tower walls is presented. In view of the very limited ductile nature of this type of construction the analysis presented herein is based on linear elastic behaviour.

• Smart Structures and Systems
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• v.10 no.4_5
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• pp.393-410
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• 2012

The 610 m high Canton Tower (formerly named Guangzhou New Television Tower) is currently considered as a benchmark problem for structural health monitoring (SHM) of high-rise slender structures. In the benchmark study task I, a set of 24-hour ambient vibration measurement data has been available for the output-only system identification study. In this paper, the vector autoregressive models (ARV) method is adopted in the operational modal analysis (OMA) for this TV tower. The identified natural frequencies, damping ratios and mode shapes are presented and compared with the available results from some other research groups which used different methods, e.g., the data-driven stochastic subspace identification (SSI-DATA) method, the enhanced frequency domain decomposition (EFDD) algorithm, and an improved modal identification method based on NExT-ERA technique. Furthermore, the environmental effects on the estimated modal parameters are also discussed.

• Wind and Structures
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• v.30 no.5
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• pp.511-524
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• 2020

Advancements in materialistic life styles and increasing awareness about adverse climatic changes and its negative effects on human life have been the driving force of finding new and clean sources of energy. Wind power has become technologically mature and commercially acceptable on global scale. However, fossil fuels have been the major sources of energy in most countries, renewable energy (particularly wind) is now booming worldwide. To cope with this wind energy technology, various related aspects have to be understood by the scientific, engineering, utility, and contracting communities. This study is an effort towards the understanding of the (i) wind turbine blade and tower structural stability issues, (ii) turbine blade and tower failures and remedial measures, (iii) weather and seismic effects on turbine blade and tower failures, (iv) gear box failures, and (v) turbine blade and tower failure analysis tools.

• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.935-937
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• 1998

The stringing load was added to tower design that consider the active load in 765kV transmission line construction. The nominal auxiliary members of steell tubular tower arm were altered into stress members by means of three dimensional design analysis method. 765kV transmission line construction also use self-standing tower that does not install temporary wire which support the section tower placed between drum field and engine field when stringing process.

• Journal of Aerospace System Engineering
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• v.6 no.1
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• pp.1-6
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• 2012

During helicopter rotor system development process, whirl tower test is conducted basically. For conducting whirl tower test during bearingless hub development process, design new blade or using existing blade with repair or remodeling. Because simple shape and efficient aerodynamic characteristic, BO-105 blade is used for hub system development widely. Originally BO-105 Blade is used for hingeless hub, so flap stiffness and lag stiffness on blade root area is relatively low. So appling BO-105 blade to bearingless hub whirl tower test, root area have to be reinforce. In this paper, suggest reinforcement method of BO-105 blade root area.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1637-1640
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• 2005

This paper presents a technique for electromagnetic field analysis on surge response due to Mid-span back-flashovers effects in lightning protection system of 500 kV EHV single circuit transmission tower by the neural networks method. These analyses are based on modeling lightning return stroke as well as on coupling the electromagnetic fields of the stroke channel to the line. The ground conductivity influences both the electric field as well as the coupling mechanism and hence the magnitude and wave shape of the induced voltage. The technique can be used to analyzed the corona voltage effect, the effective of stroke to the span tower, the surge impedance of transmission lines. The maximum voltage from flashovers effects in the lines. The model is compatible with general electromagnetic transients programs such as the ATP-EMTP. The simulation results show that this study analyses for time-domain with those produced by a cascade multi-section model, the surge impedance of a full-sized tower hit directly by a lightning stroke is discussed.

• International Journal of High-Rise Buildings
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• v.5 no.3
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• pp.213-220
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• 2016

The "China Zun" tower in Beijing will rise to 528 meters in height and will be the tallest building in Beijing once built. Inspired by an ancient Chinese vessel, the "Zun", the plan dimensions reduce gradually from the bottom of the tower to the waist and then expand again as it rises to form an aesthetically beautiful and unique geometry. To satisfy the structural requirement for seismic and wind resistance, the structure is a dual system composed of a perimeter mega structure made of composite mega columns, mega braces, and belt trusses, and a reinforced-concrete core with steel plate-embedded walls. Advanced parametric design technology is applied to find the most efficient outer-perimeter structure system. The seismic design basically follows a mixed empirical and performance-based methodology that was verified by a shaking table test and other specimen lab tests. The tower is now half-way through its construction.