• Computational Structural Engineering
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• v.11 no.3
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• pp.155-164
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• 1998

이 논문은 변단면을 고려한 수평 곡선보의 자유진동에 관한 연구이다. 진동시 곡선보 요소에 작용하는 합응력과 관성력의 동적평형방정식을 이용하여 변단면 원호형 수평 곡선보의 자유진동을 지배하는 상미분방정식을 유도하였다. 이 미분방정식을 원형 단면을 갖는 선형변변단면에 적용하여 고유진동수, 진동형 및 합응력을 산출하였다. 수치 해석예에서는 양단고정 및 양단회전 곡선보를 채택하였으며, 수치해석 결과로서 고유진동수와 단면비, 세장비 및 중심각 사이의 관계를 그림에 나타내었다. 또한 실험실 규모의 실험을 통하여 본 연구결과의 타당성을 보였다.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.15 no.1
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• pp.189-195
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• 2002

This paper deals with the free vibration of horizontally curved beams with transition currie. Based on the dynamic equilibrium equations of a curved beam element subjected to the stress resultants and inertia forces, the governing differential equations are derived for the out-of-plane vibration of curved beam with variable curvature. These equations are applied to the beam having transition curve in which the clothiod curve is chosen in this study. The differential equations are solved by the numerical methods lot calculating the natural frequencies and mode shapes. For verifying theories developed herein, the frequency parameters obtained from this studs and ADINA are compared with each other. As the numerical results, the various parametric studies effecting on natural frequencies are investigated and those results are presented in tables and figures.

• Computational Structural Engineering
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• v.9 no.1
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• pp.133-139
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• 1996

In this paper, an approximate method is developed to obtain the natural frequencies of the out of plane vibration of circular curved beams. The governing differential equations are derived using the dynamic equilibrium equations with the Timoshenko theory, and solved numerically. The Runge-Kutta method and Regula-Falsi method are used to integrate the differential equations and to determine the natural frequencies, respectively. In numerical examples, the hinged-hinged and clamped-clamped end constraints are considered. For each case, the four lowest natural frequencies are reported as functions of four non-dimensional system parameters.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.3
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• pp.419-429
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• 1992

본 연구에서는 면외 변형이 가능한 평면 곡선보에 수정 형상함수를 적용하여 탈락성 및 지속성 에너지에 포함된 가성구속에 의한 수치해의 거동을 고찰함과 동시에, 가성구속에 의한 오차 발생 요인이 제거된, 면외 변형이 가능한 평면 곡선보의 선형 요소를 제안하고자 한다.

• Journal of the Society of Disaster Information
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• v.14 no.3
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• pp.379-386
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• 2018

Purpose: This study was to the fragility evaluation of I-shape curved beam structure subjected to strong ground motions including Gyeongju and Pohang earthquakes Method: In particular, to conduct the analytical model, ABAQUS and ANSYS platform was used in this study. Furthermore, the analytical model using 3D Finite Element Model (FEM) was validated, in comparison to the theoretical solutions at the location of 025L, 05L, and 0.75L in static loading condition. In addition, in order to evaluate the seismic fragility of the curved beam structure, 20 seismic ground motions were selected and Monte-Carlo Simulation was used for the empirical fragility evaluation from 0.2g to 1.5g. Result: It was interesting to find that the probability of the system failure was found at 0.2g, as using 190 MPa limit state and the probability of the failure using 390 MPa limit state was starting from 0.6g. Conclusion: This study showed the comparison of the theoretical solution with analytical solution on I-shaped curved beam structures and it was interesting to note that the system subjected to strong ground motions was sensitive to high frequency earthquake. Further, the seismic fragility corresponding to the curved beam shapes must be evaluated.

• Journal of the Society of Naval Architects of Korea
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• v.32 no.4
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• pp.1-8
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• 1995

This paper is presented determination of the hull form factors about a high speed coastal fishing boat using Fuzzy modeling. That is, the estimation curves of total resistance & EHP(Efficiency Horse Power) are induced by Fuzzy modeling algorithm from data of accumulated hull form factors and are compared with the results of model test. Also, the estimation curves of total resistance & EHP are utilized efficiently in determination the hull form factors about a high speed coastal fishing boat.

• Computational Structural Engineering
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• v.2 no.4
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• pp.79-88
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• 1989

The behavior of composite beams in steel building structures subjected to lateral loading is studied. Mathematical models for the stiffness of composite beams and the strength at the connections, which are dependent on details of the connections are developed based on the previous experimental results and the results from numerical analyses. Analytical models for the skeleton and hysteresis curves of cantilever composite beams are also presented. A single component model for the composite beam, consisting of elastic beam and the end springs at which all the inelstic deformations within a member are lumped, is implemented into the computer program, DRAIN-2D. And a comparison of analytical results is made with the experimental results.

• Computational Structural Engineering
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• v.5 no.1
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• pp.75-82
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• 1992

In the h-version of F.E.M., all piecewisely smooth curved boundaries can be approximated by a sufficient number of straight-sided elements. However, in the p-version the size of the element is usually large and hence the probability of distortions is more. An attempt has been made to generate a curved boundary by using a transfinite interpolation technique to avoid the discretization errors. In the following sections, it will be shown how to construct transfinite interpolants both in h-version and in p-version over polygonal and nonpolygonal regions. Three numerical tests are shown to validate the applicability and superior capability of transfinite interpolation technique.

• Journal of Korean Society of Steel Construction
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• v.14 no.6
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• pp.793-802
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• 2002

This study presented a finite element formulation for the dynamic analysis of horizontally curved I-girder bridges. The stiffness and mass matrices of the curved and the straight beam elements are formulated. Each node of both elements has seven degrees of freedom, including the warping degree of freedom. The curved beam element is derived from Kang and Yoo's theory of thin-walled curved beams. The computer program EQCVB has been developed to perform dynamic analyses of various horizontally curved I-girder bridges. The Gupta method is used to solve the eigenvalue problem efficiently, while the Wilson-${\theta}$ method is used for the seismic analysis. The efficiency of EQCVB is demonstrated by comparing solution time with ABAQUS. Using EQCVB, the study is applied to investigate the dynamic behavior of horizontally curved I-girder bridges under seismic loading.

• Journal of Astronomy and Space Sciences
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• v.13 no.1
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• pp.72-78
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• 1996

We evaluated the orbital elements of BV light curves of a short period RS CVn type eclipsing binary system UV Picsium that shows complication light variation, by analyzing with the Winson-Devinney's differential correction method. Because the analyzed light curves shows large light variation at outside eclipse region, we assumed spotted region of the primary component and calculated its position and size. The results show the UV Psc is a detached binary system of nearly the same radii and the primary component has high mass with high temperature. However this result is not consistant with customary stellar models, thus requires more observational data to confirm this problem.