• Title/Summary/Keyword: wind forces

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A Study on an Energy-Effective Site Planning for a Residential Environment(II) (에너지 절약형 주택단지 설계기법에 관한 연구 (II))

  • 양병이;김기호
    • Journal of the Korean Institute of Landscape Architecture
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    • v.13 no.1
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    • pp.25-42
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    • 1985
  • The objective of this article is to develop residential site planning techniques for the energy conservation by focusing on energy conscious site design process, influencing natural factors for energy conservation and suggestion of multi - family housing Prototypes. This article is the second part of the article titled "A Study on an Energy - Effective Site Planning for a Residential Environment"which is published in the previous issue (Vol. 12, No. 2) of this journal. The first part of the article dealt with how to make best use of energy conserving effect of natural forces such as sun, wind and water, and the selection techniques of suitable residential site for achieving energy conservation. The second part proposes the energy conscious design process of residential site development and suggests building forms of single family and multi -family housings. The three multi - family housing prototypes haute been developed which are most energy -effective ; the linear type, the cut -de -sac type and the atrium type. In the process of creating the prototypes, energy conserving design criteria have been also developed. These criteria can be used to develop some other alternative prototypes.

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Instability of pipes and cables in non-homogeneous cross-flow

  • Riera, Jorge D.;Brito, J.L.V.
    • Wind and Structures
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    • v.1 no.1
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    • pp.59-66
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    • 1998
  • The vibrations of bodies subjected to fluid flow can cause modifications in the flow conditions, giving rise to interaction forces that depend primarily on displacements and velocities of the body in question. In this paper the linearized equations of motion for bodies of arbitrary prismatic or cylindrical cross-section in two-dimensional cross-flow are presented, considering the three degrees of freedom of the body cross-section. By restraining the rotational motion, equations applicable to circular tubes, pipes or cables are obtained. These equations can be used to determine stability limits for such structural systems when subjected to non uniform cross-flow, or to evaluate, under the quasi static assumption, their response to vortex or turbulent excitation. As a simple illustration, the stability of a pipe subjected to a bidimensional flow in the direction normal to the pipe axis is examined. It is shown that the approach is extremely powerful, allowing the evaluation of fluid-structure interaction in unidimensional structural systems, such as straight or curved pipes, cables, etc, by means of either a combined experimental-numerical scheme or through purely numerical methods.

Effect of Plan Irregularity and Beam Discontinuity on Structural Performances of Buildings under Lateral Loadings

  • Islam, Md. Rajibul;Chakraborty, Sudipta;Kim, Dookie
    • Architectural research
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    • v.24 no.2
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    • pp.53-61
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    • 2022
  • Irregularities in the structure are crucial factors in screening structural vulnerability under extreme loadings. Numerical analyses were carried out considering wind and seismic loadings for four structures with discrete irregularity: continuous and discontinuous beams with varied story levels, and L-shaped irregular buildings. Structural responses such as maximum displacements, bending moments, axial forces, torsions, and story drifts are evaluated as per the criteria and limits defined by ACI 318. The outcomes indicate that the frame system with beam discontinuity on the upper half of the height exhibits the best structural performance. The results also indicate that the asymmetrical design of the L-shaped model makes it more susceptible to damage when subjected to strong lateral loading conditions.

Analysis of Berthing Velocity of Ship and Application to Safe Pilotage (선박접안속도 분석과 안전도선에의 활용)

  • Ik-Soon Cho;Eun-Ji Kang
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2022.11a
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    • pp.149-150
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    • 2022
  • External forces acting on the mooring facilities include wave, wind, current, and ship's kinetic energy. In particular, the ship's kinetic energy is changing as the ship become larger, and larger carrying capacity. It was intended to analyze the berthing velocity measurement data at on tanker terminals equipped with a DAS (Docking Aid System) through statistical means and algorithms and use it as basic data for safer and more efficient pier design and pilotage.

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Shenzhen Rural Commercial Bank Headquarters: an Iconic Tower Defined by the Integration of Architecture, Structure and Sustainability Goals

  • Besjak, Charles;Thewis, Alexandra
    • International Journal of High-Rise Buildings
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    • v.11 no.1
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    • pp.31-39
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    • 2022
  • The seamless integration of the architecture and structure of a tall building plays a key role in establishing a recognizable and iconic design. The structural system developed for Shenzhen Rural Commercial Bank Headquarters (SRCBH) utilizes enhanced structural innovations unique to the tower's geometry to improve structural and sustainability performance. SRCBH utilizes a steel diagrid system pulled outside of the enclosure line with diaphragm forces resolved primarily by corner diagonal beams. During the design process the structural systems underwent performance based design and optimization for wind and seismic loading. Resiliency was prioritized for structural design as well as fire resistance. More closely integrating the structure of a building with its architecture and sustainability goals can lead to unique and innovative towers with a timeless expression.

Computation of aerodynamic coefficients of a re-entry vehicle at Mach 6

  • R.C. Mehta;E. Rathakrishnan
    • Advances in aircraft and spacecraft science
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    • v.10 no.5
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    • pp.457-471
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    • 2023
  • The paper evaluates the aerodynamic coefficients on a blunt-nose re-entry capsule with a conical cross-section followed by a cone-flare body. A computer code is developed to solve three-dimensional compressible inviscid equationsfor flow over a Space Recovery Experiment (SRE) configuration at different flare-cone half-angle at Mach 6 and angle of attack up to 5°, at 1° interval. The surface pressure variation is numerically integrated to obtain the aerodynamic forces and pitching moment. The numerical analysis reveals the influence of flare-cone geometry on the flow characteristics and aerodynamic coefficients. The numerical results agree with wind tunnel results. Increase of cone-flare angle from 25° to 35° results in increase of normal force slope, axial forebody drag, base drag and location of centre of pressure by 62.5%, 56.2% and 33.13%, respectively, from the basic configuration ofthe SRE of 25°.

A Model-Fitting Approach of External Force on Electric Pole Using Generalized Additive Model (일반화 가법 모형을 이용한 전주 외력 모델링)

  • Park, Chul Young;Shin, Chang Sun;Park, Myung Hye;Lee, Seung Bae;Park, Jang Woo
    • KIPS Transactions on Computer and Communication Systems
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    • v.6 no.11
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    • pp.445-452
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    • 2017
  • Electric pole is a supporting beam used for power transmission/distribution which accelerometer are used for measuring a external force. The meteorological condition has various effects on the external forces of electric pole. One of them is the elasticity change of the aerial wire. It is very important to perform modelling. The acceleration sensor is converted into a pitch and a roll angle. The meteorological condition has a high correlation between variables, and selecting significant explanatory variables for modeling may result in the problem of over-fitting. We constructed high deviance explained model considering multicollinearity using the Generalized Additive Model which is one of the machine learning methods. As a result of the Variation Inflation Factor Test, we selected and fitted the significant variable as temperature, precipitation, wind speed, wind direction, air pressure, dewpoint, hours of daylight and cloud cover. It was noted that the Hours of daylight, cloud cover and air pressure has high explained value in explonatory variable. The average coefficient of determination (R-Squared) of the Generalized Additive Model was 0.69. The constructed model can help to predict the influence on the external forces of electric pole, and contribute to the purpose of securing safety on utility pole.

A Study on Evaluation Technique of Manoeuvring Difficulty by Using the Ship Manoeuvre Simulator for Berthing/Deberthing (선박 접이안 조종 시뮬레이터를 이용한 조종위험도 평가 기법에 관한 연구)

  • Yang Seung-Yeul;Sohn Kyoung-Ho;Lee Hee-Yong;Ha Mun-Keun;Kim Hyun-Soo;Lee Jin-Ho;Im Nam-Kyun
    • Journal of Navigation and Port Research
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    • v.29 no.3 s.99
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    • pp.189-194
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    • 2005
  • The berthing/deberthing manoeuvring operation is the peculiar work owned to the marine pilot and the dock master. So, in the port or the shipyard, the berthing/deberthing manoeuvring operation requires considerable concentration and bears dangerousness. In that situation, a tug utilization is getting increased and the external forces have an effect on the own ship because of moving with low advance speed. In this study, we constructed the 2-dimensional virtual ship manoeuvring simulator system with which we can carry out the berthing/deberthing manoeuvring operation by using tugs in the external forces such as strong wind. And then, we propose the objective indexes by which the degree of manoeuvring difficulty evaluated. Using the present system, we carry out manoeuvring simulation experiment in order to grasp correlation between the objective indexes proposed here and the def{ree of manoeuvring difficulty felt by operator. Lastly, we discuss the evaluation technique of manoeuvring difficulty.

Optimization Design of Damping Devices for a Super-Tall Building Using Computational Platform (전산플랫폼을 이용한 초고층구조물의 감쇠장치 최적화 설계)

  • Joung, Bo-Ra;Lee, Sang-Hyun;Chung, Lan;Choi, Hyun-Chul
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.28 no.2
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    • pp.145-152
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    • 2015
  • In the study, the effects of damping devices on damping ratio increase and wind-load reduction were investigated based on the computational platform, which is one of the parametric modeling methods. The computational platform helps the designers or engineers to evaluate the efficacy of the numerous alternative structural systems for irregular Super-Tall building, which is crucial in determining the capacity and the number of the supplemental damping devices for adding the required damping ratios to the building. The inherent damping ratio was estimated based on the related domestic and foreign researches conducted by using real wind-load records. Two types of damping devices were considered: One is inter-story installation type passive control devices and the other is mass type active control devices. The supplemental damping ratio due to the damping devices was calculated by means of equivalent static analysis using an equation suggested by FEMA. The optimal design of the damping devices was conducted by using the computational platform. The structural element quantity reduction effect resulting from the installation of the damping devices could be simply assessed by proposing a wind-load reduction factor, and the effectiveness of the proposed method was verified by a numerical example of a 455m high-rise building. The comparison between roof displacement and the story shear forces by the nonlinear time history analysis and the proposed method indicated that the proposed method could simply but approximately estimate the effects of the supplemental damping devices on the roof displacement and the member force reduction.

A Statistical Analysis of External Force on Electric Pole due to Meteorological Conditions (기상현상에 의한 전주 외력의 통계적 분석)

  • Park, Chul Young;Shin, Chang Sun;Cho, Yong Yun;Kim, Young Hyun;Park, Jang Woo
    • KIPS Transactions on Computer and Communication Systems
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    • v.6 no.11
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    • pp.437-444
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    • 2017
  • Electric Pole is a supporting beam used for power transmission/distribution which is sensitive to external force change of environmental factors. Therefore, power facilities have many difficulties in terms of maintenance/conservation from external environmental changes and natural disasters that cause a great economic impact. The aerial wire cause elasticity due to the influence of temperature, or factors such as wind speed and wind direction, that weakens the electric pole. The situation may lead to many safety risk in day-to-day life. But, the safety assessment of the pole is carried out at the design stage, and aftermath is not considered. For the safety and maintenance purposes, it is very important to analyze the influence of weather factors on external forces periodically. In this paper, we analyze the acceleration data of the sensor nodes installed in electric pole for maintenance/safety purpose and use Kalman filter as noise compensation method. Fast Fourier Transform (FFT) is performed to analyze the influence of each meteorological factor, along with the meteorological factors on frequency components. The result of the analysis shows that the temperature, humidity, solar radiation, hour of daylight, air pressure, wind direction and wind speed were influential factors. In this paper, the influences of meteorological factors on frequency components are different, and it is thought that it can be an important factor in achieving the purpose of safety and maintenance.