• Title/Summary/Keyword: Slender body

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On the wind and earthquake response of reinforced concrete chimneys

  • Turkeli, Erdem;Karaca, Zeki;Ozturk, Hasan Tahsin
    • Earthquakes and Structures
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    • v.12 no.5
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    • pp.559-567
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    • 2017
  • Slender structures like reinforced concrete (RC) chimneys are severely damaged or collapsed during severe wind storms or strong ground motions all over the world. Today, with the improvement in technology and industry, most factories need these slender structures with increasing height and decreasing in shell thickness causing vulnerable to winds and earthquakes. Main objectives in this study are to make structural wind and earthquake analysis of RC chimneys by using a well-known international standard CICIND 2001 and real recorded time history accelerations and to clarify weak points of these tall and slender structures against these severe natural actions. Findings of this study show that maximum tensile stress and shear stress approximately increase 103.90% and 312.77% over or near the openings on the body of the RC chimneys that cause brittle failure around this region of openings.

Numerical Analysis on the Wave Resistance for Development of Ship`s From of Tuna Purse Seiner (참치 선망어선의 선형개발을 위한 조파저항의 수치해석)

  • 김인철
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.28 no.2
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    • pp.228-239
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    • 1992
  • The purpose of the present research is to develop an efficient numerical method for the calculation of potential flow and predict the wave-making resistance for the application to ship design of tuna purse seiner. The paper deals with the numerical calculation of potential flow around the series 60 with forward velocity by the new slender ship theory. This new slender ship theory is based on the asymptotic expression of the Kelvin-source, distributed over the small matrix at each transverse section so as to satisfy the approximate hull boundary condition due to the assumption of slender body. Some numerical results for series 60, C sub(b) =0.6, hull are presented in this paper. The wave pattern and wave resistance are computed at two Froude numbers, 0.267 and 0.304. These results are better than those of Michell's thin ship theory in comparison with measured results. However, it costs much time to compute not only wave resistance but also wave pattern over some range of Froude numbers. More improvements are strongly desired in the numerical procedure.

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An Experimental Study of Asymmetric Vortices around Slender Bodies during High Angle of Attack Maneuver (세장형 몸체의 고받음각 기동에서 발생하는 비대칭와류에 관한 실험적 연구)

  • Jeon, Young-Jin;Seo, Hyung-Seok;Choi, Wom-Hyeok;Byun, Yung-Hwan;Lee, Jae-Woo
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2008.05a
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    • pp.71-76
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    • 2008
  • In this study, side force, drag, and the yawing moment were measured based on the angle of attack by using two models of different nose shapes with slender bodies, which were general shapes in the subsonic area. As a result, the side force and yawing moment were the highest at a specific angle of attack. The boundary between asymmetrical normal state and asymmetrical abnormal state were able to be seen. As a result of analyzing the side force, drag, and yawing moment by time, reliability varied depending on the shape of the head at the same angle of attack. The results of measuring pressure distribution from the surface of the slender body at each angle of attack were as follows: as the angle of attack gets higher, the distribution of surface pressure was asymmetrical.

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The Type of the Lower Body Shape of the Elderly Women Using the 3D Anthropometric Data -Focused on Women Aged 70-85- (3차원 계측데이터를 활용한 고령 여성의 하반신 체형 유형화 -70-85세 여성을 중심으로 -)

  • Cha, Su Joung
    • Journal of Fashion Business
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    • v.22 no.2
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    • pp.27-39
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    • 2018
  • This study analyzed the body shape of women over 70 years and classified their body shapes in order to provide basic data for the development of pants patterns that can complement the weakness of the body shape of elderly women. It were analyzed using SPSS Ver. 20.0. Five factors were extracted from the lower body: obesity and thigh thickness, lower body length, under knee thickness, ankle height, and hip sag. In type 1, the lower body was obese and the legs were thick, but the hips were not sagging. It was named 'high-hip obesity figure'. Type 2's abdomen, hip, and waist were obese, but the legs were thin and the hip were not sagging. Thus, 'bird-leg middle obesity figure' was the name. Type 3 had a long and slender lower body, but legs were thick and the hips were saggy, it was named 'strong-leg low-hip slender figure'. The elderly women showed less difference in waist, abdomen, and hip circumference. The abdominal circumference was 2-3cm more than the waist and hip circumference; hence there is a need to differentiate the shape and number of darts in the production of bottom-wear patterns for older women. In addition, the leg circumference is gradually reduced by aging compared to the size of the lower body. Therefore, it would be necessary to search for a method that can effectively design the difference between the hip circumference and the leg circumference in relation to the body shape and the aesthetics of older women.

Numerical Simulation of Asymmetric Vortical Flows on a Slender Body at High Incidence (큰 받음각을 갖는 세장형 물체 주위의 점성 유동장 수치 모사)

  • Rho Oh Hyun;Hwang Soo Jung
    • Journal of computational fluids engineering
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    • v.1 no.1
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    • pp.98-111
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    • 1996
  • The compressible laminar and turbulent viscous flows on a slender body in supersonic speed as well as subsonic speed have been numerically simulated at high angle of attack. The steady and time-accurate compressible thin-layer Navier-Stokes code based on an implicit upwind-biased LU-SGS algorithm has been developed and specifically applied at angles of attack of 20, 30 and 40 dog, respectively. The modified eddy-viscosity turbulence model suggested by Degani and Schiff was used to simulate the case of turbulent flow. Any geometric asymmetry and numerical perturbation have not been intentionally or artificially imposed in the process of computation. The purely numerical results for laminar and turbulent cases, however, show clear asymmetric formation of vortices which were observed experimentally. Contrary to the subsonic results, the supersonic case shows the symmetric formation of vortices as indicated by the earlier experiments.

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Numerical Simulation of Flow Around a Slender Body at High Angle of Attack (큰 받음각을 갖는 세장형 물체 주위의 점성 유동장 수치 모사)

  • Rho Oh Hyun;Hwang Soo Jung
    • 한국전산유체공학회:학술대회논문집
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    • 1995.10a
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    • pp.3-10
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    • 1995
  • The compressible laminar and turbulent viscous flow on a slender body in supersonic speed as well as subsonic speed has been numerically simulated at high angle of attack. The steady and time-accurate compressible thin-layer Navier-Stokes code based on an implicit upwind-biased LU-SGS algorithm has been developed and specifically applied at angles of attack of 20, 30, 40 deg, respectively. The modified eddy-viscosity turbulence model suggested by Degani and Schiff was used to simulate the case of turbulent flow. Any geometric asymmetry and numerical perturbation have not been intentionally or artificially imposed in the process of computation. The purely numerical results for laminar and turbulent cases, however, show clear asymmetric formation of vortices which were observed experimentally. Contrary to the subsonic results, the supersonic case shows the symmetric formation of vortices as indicated by the earlier experiments.

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A study on critical load due to external force influencing on flight characteristics of a small slender body rocket. (가늘고 긴 소형로켓의 비행특성에 영향을 주는 외력에 기인한 임계하중에 관한 연구)

  • Go, Tae-Sig;Na, Seon-Hwa
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2007.11a
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    • pp.393-397
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    • 2007
  • The aim of this study is to investigate critical load, which can influence on flight path of a small slender body rocket, due to external forces such as thrust, drag and weight. The critical load was firstly obtained from Euler column equation, and compared with analysis results using Finite Element Method to evaluate the theoretical critical load.

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A Study on the Hydrodynamic Interaction Forces between Ship and Bank Wall in the Proximity of Bank (측벽부근을 항해하는 선박과 측벽간의 상호 간섭력에 관한 연구)

  • Lee, Chun-Ki;Kang, Il-Kwon
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.40 no.1
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    • pp.73-77
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    • 2004
  • It is well known that the hydrodynamic interaction forces between ship and bank wall affect ship manoeuvring motions. In this paper, the calculation method based on the slender body theory for estimation of the hydrodynamic interaction forces between ship and bank wall is investigated. The numerical simulations on hydrodynamic interaction force acting on a ship in the proximity of bank wall are carried out by using this theoretical method. The theoretical method used in this paper will be useful for practical prediction of ship manoeuvrability at the initial stage of design, for discussion of marine traffic control system and for automatic control system of ship in confined waterways.

A Study on the Stream Lines Calculation around a Ship's Hull (선체주위(船體周圍)의 유선계산법(流線計算法)에 관(關)한 연구(硏究))

  • K.J.,Cho;S.W.,Hong;C.W.,Park
    • Bulletin of the Society of Naval Architects of Korea
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    • v.14 no.2
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    • pp.1-9
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    • 1977
  • Streamlines around a ship's hull can be calculated by using streamline tracing method replacing the ship section with distribution of singularity. The influence of frame lines on the stream surrounding a hull surface, however, can not be found. Jinnaka studied on streamlines for Lewis form by applying the slender body theory. The influence of frame lines on stream surrounding a hull surface is well found in Jinnaka's method. In this paper streamline calculation method for chine type has been developed by using conformal transformation and applying slender body theory as Jinnaka did. Three kinds of model-one of series 62 for chine type, V.L.C.C. and high speed craft built in Korea for Lewis form-were used for streamline calculation;

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A Study on the Princess Line by Body Types (Part I) - Focused on Body Types of A & H -

  • Kim, Sook-Jung;Suh, Mi-A
    • The International Journal of Costume Culture
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    • v.4 no.3
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    • pp.182-194
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    • 2001
  • The main purpose is to study lines on different body types and to disguise any imperfections by using diverse princess lines. We separated festers body shapes into specific body types, A, H by applying both the direct and the indirect measurements. Following are the results of the study: 1. nose are the resulting illusion effects when the shoulder width of the princess line was fixed. In case of the armhole princess line, the illusion that the waist intervals were narrow or wide in A-line silhouette. In case the shoulder princess line, when the waist interval was narrow, it appeared to show narrow shoulder in A-line silhouette. While the wide waist interval shows the wide shoulder width in H-line silhouette. It regards body type H in the same light as H-line silhouette when the waist interval is narrow, it appeared to show narrow shoulder width in A-line silhouette. When the waist interval was wide, it appeared to give the narrow shoulder width. 2. When the princess lines waist width was fixed in order to study illusion effects of waist widths. Generally, for body type A, Whether the waist interval princess line is narrow or wide, the princess line is located comparatively wide, in A-line silhouette appeared to show relatively slender waist. For body type H, whether the waist interval is narrow or wide, the princess line us situated comparatively narrow interval, H-line silhouette appeared to show sum waist but the differences are not significant 3. The illusion of the hip were studied by fixating the width of the skirt and varying the locations of princess line and waist widths. For the location of both armhole and shoulder princess line in H and A-line silhouette, the narrow shoulder width and the waist appeared to show narrow hips. mile they are wide appeared to show wide hips. 4. With both waist and skirt width fuel, all two body types showed taller and slender postures when the princess line originated from the shoulder compare to the armhole.

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