• Title/Summary/Keyword: parametric equations

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Relationship between Ductility and Confinement Steel of RC Bridge Columns (철근콘크리트 교각의 연성도와 심부구속철근량의 상관관계)

  • 손혁수;한상엽;이재훈
    • Proceedings of the Korea Concrete Institute Conference
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    • 2002.10a
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    • pp.141-146
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    • 2002
  • The purpose of this study is to develop a reasonable design for transverse confinement reinforcement considering ductility and required transverse confinement reinforcement of RC bridge columns. In order to develop relationships between the curvature ductility and required transverse confinement reinforcement for design purpose, the analysis using the computer program NARCC have been carried out for parametric studies. Based on the results from the parametric studies, an equation for calculating the required transverse confinement reinforcement based on ductility demand was developed for seismic design of RC bridge columns. The equations proposed by this study will provide more reasonable and more effective design guidelines for performance-based seismic design of RC bridge columns.

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Dynamic Stability of a Free-Free Beam with a Tip Rigid Body under a Controlled Pulsating Thrust (끝단 강체를 갖고 맥동 제어추력을 받는 양단 자유보의 동적 안정성)

  • Ryu, Bong-Jo;Lee, Gyu-Seop;Seong, Yun-Gyeong;Choe, Bong-Mun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.1 s.173
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    • pp.232-239
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    • 2000
  • The paper describes the parametric instability of free-free beams subjected to a controlled pulsating follower force. The beam has a tip rigid body not a mass point, and the direction of pulsating follower force is controlled by the direction control sensor. Equations of motion are derived by Hamilton's principle and the instability regions are obtained by finite element formulation. The effects of magnitude, rotary inertia, the distance between free end of the beam and the center of gravity of the rigid body on the instability types and regions are investigated by the change of the constant and periodic part of the follower force.

Motion of a Cylindrical Object due to Seabed Soil Friction (해저면 토양마찰력에 의한 원통형 물체의 운동)

  • 최경식;강신영;곽한우
    • Journal of Ocean Engineering and Technology
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    • v.6 no.1
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    • pp.19-28
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    • 1992
  • The motion of a cylindrical object resting on shallow seabed due to wave forces and soil friction is studied. Given environmental conditions such as wave characteristics and seabed soil properties, the equations of motion are derived and the corresponding reponses of the cylinder in two dimensional plane, i.e., translational and rotational displacements, accelerations, are calculated. The motion is substantially restrained by the penetration of a cylinder into seabed and the parametric study focuses on finding out a minimum penetration depth which makes the cylinder motionless.

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A Parametric Study of Denting Using a Simplified Design Approach (단순한 디자인 방법을 이용한 덴팅 영향인자에 관한 연구)

  • Jeong, Dong-Won
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.8
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    • pp.1472-1479
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    • 2002
  • In order to improve automotive fuel economy, vehicle weight should be reduced. Achieving significant weight reductions will normally require reducing the panel thickness or using alternative materials such as aluminum alloy sheet. These changes will affect the dent resistance of the panel. In this study, the correlation between panel size, curvature, thickness, material properties and dent resistance is investigated. A parametric approach is adopted, utilizing a "design software" tool incorporating empirical equations to predict denting and panel stiffness for simplified panels. The most effective period to optimize an automotive body panel is early in its development. The developed design program can be used to minimize panel thickness or compare different materials, while maintaining adequate panel performance.

Parametric Study of Composite Laminated Conical Shells (복합적층 원뿔형 쉘의 파라미터 연구)

  • Son, Byung-Jik;Jung, Dae-Suck
    • Journal of the Korean Society of Safety
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    • v.22 no.5
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    • pp.41-49
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    • 2007
  • In general, the curved structures have the engineering efficiency as well as a fine view compared with straight member. Also, composite materials are composed of two or more different materials to produce desirable properties for structural strength as compared to single ones. Shell structures with composite materials have many advantages in strength and weight reduction. Therefore, composite laminated conical shells are analyzed in this study. To solve differential equations of conical shells, this paper used finite difference method. Various parametric study according to the change of radius ratio, vertex angle and subtended angle are examined. The change of radius ratio, vertex angle and subtended angle mean the change from conical shells to cylindrical shells, conical shells to circular plates and open shells closed shells, respectively.

Walk-off Output Characteristics of OPO Pumpedby SHG of Nd:YAG Laser (Nd:YAG 레이저의 SHG로 펌핑된 OPO의 Walk-off 출력특성)

  • 이용우
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2003.05a
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    • pp.419-423
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    • 2003
  • In this paper, we have constructed singly resonant KTP OPO system pumped by 532 nm to obtain broadly frequency tunable pulses. Also we have mathematically simulated frequency tuning range, phase matching angle for 900 nm output and threshold energy, and we calculated output intensity using wave propagation equations for optical parametric oscillator which include walk-off, pump depletion.

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Residual Strength of Damaged Tubulars under Combined Axial Compression, Hydrostatic Pressure and End Bending Moment (복합 하중에 대한 손상 원통의 잔류강도)

  • Cho, Sang-Rai;Gwak, Dong-Il
    • Journal of Ocean Engineering and Technology
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    • v.3 no.2
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    • pp.118-124
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    • 1989
  • In this paper a design formula has been proposed to predict the residual strength of damaged tubulars subjected to combined axial copression, hydrostatic pressure and end bending loadings. A theoretical analysis method was employed to calculate the residual strengths, in which the geometric configuration of damaged tubulars is realistically described using empirically derived equations. The predictions using this method have been compared with relevent experimental results to demonstrate their validity and accuracy. A rigorous parametric study has been conducted using the method, and then a design formula has been derived based upon the parametric study results.

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Residual Strength of Damaged Tubulars under Combined Axial Compression, Hydrostatic Pressure and End Bending Moment (복합 하중에 대한 손상 원통의 잔류강도)

  • Cho, Sang-Rai;Gwak, Dong-Il
    • Journal of Ocean Engineering and Technology
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    • v.3 no.2
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    • pp.618-618
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    • 1989
  • In this paper a design formula has been proposed to predict the residual strength of damaged tubulars subjected to combined axial copression, hydrostatic pressure and end bending loadings. A theoretical analysis method was employed to calculate the residual strengths, in which the geometric configuration of damaged tubulars is realistically described using empirically derived equations. The predictions using this method have been compared with relevent experimental results to demonstrate their validity and accuracy. A rigorous parametric study has been conducted using the method, and then a design formula has been derived based upon the parametric study results.

HEAT-TRANSFER ANALYSIS OF A COOLING CHANNEL WITH INCLINED ELLIPTICAL DIMPLES (기울어진 타원형 딤플이 부착된 냉각 유로에 대한 열전달 성능해석)

  • Kim, H.M.;Moon, M.A.;Kim, K.Y.
    • Journal of computational fluids engineering
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    • v.17 no.1
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    • pp.1-7
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    • 2012
  • This paper deals with a parametric study on inclined elliptical dimples to enhance heat transfer in a channel. Three-dimensional Reynolds-averaged Naiver-Stokes equations are solved to estimate flow and heat transfer in dimpled channel. As turbulence closure, the low-Re shear stress transport model is employed. Two non-dimensional geometric variables, dimple ellipse diameter ratio and angle of main diameter to flow direction are selected for the parametric study. The inclined elliptical dimples show higher heat-transfer performance but with higher pressure drop compared to the circular dimples. And there is an optimum inclination angle that gives the maximum heat transfer.

Confinement Steel based on Ductility Demand for RC Bridge Columns (철근콘크리트 교각의 연성요구량에 따른 심부구속철근량)

  • 손혁수;한상엽;조재원;이재훈
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2002.09a
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    • pp.322-329
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    • 2002
  • The purpose of this study is to develop a reasonable design for transverse confinement reinforcement considering ductility and required transverse confinement reinforcement of RC bridge columns. In order to develop relationships between the curvature ductility and the displacement ductility, the analysis for total 21,600 columns using the computer program NARCC have been carried out for parametric studies. Based on the results from the parametric studies, a correlation equation between the curvature ductility and the displacement ductility was developed. In addition, an equation for calculating the required transverse confinement reinforcement based on ductility demand was developed for seismic design of RC bridge columns. The equations proposed by this study will provide more reasonable and more effective design guidelines for performance-based seismic design of RC bridge columns.

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