• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.340-343
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• 2007

The differential equations governing free, in-plane vibrations of non-circular arches with the translational (radial and tangential directions) and rotational springs at the ends, including the effects of rotatory inertia, shear deformation and axial deformation, are solved numerically using the corresponding boundary conditions. The lowest four natural frequencies for the parabolic geometry are calculated over a range of non-dimensional system parameters: the arch rise to span length ratio, the slenderness ratio, and the translational and rotational spring parameters.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.801-804
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• 2006

The purpose of this paper is to investigate the stability of stepped cantilever columns with a tip mass of rotatory inertia and a translational spring at one end. The column model is based on the Bernoulli-Euler theory which neglects the effects of rotatory inertia and shear deformation. The governing differential equation for the free vibration of columns with stepwise variable cross-section and subjected to a subtangential follower force is solved numerically using the corresponding boundary conditions. And the bisection method is used to calculate the critical divergence/flutter load. The frequency and critical divergence/flutter load for the stepped column with a single step are presented as functions of various non-dimensional system parameters: the segmental length parameter, the section ratio, the subtangential parameter, the mass, the moment of inertia of the mass, and the spring parameter.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.1181-1184
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• 2007

The differential equations governing free, in-plane vibrations of linearly elastic circular arches with rotationally flexible supports, including the effects of rotatory inertia, shear deformation and axial deformation, are solved numerically using the corresponding boundary conditions. The lowest four natural frequencies and the corresponding mode shapes are obtained over a range of non-dimensional system parameters: the subtended angle, the slenderness ratio, and the rotational spring stiffness.

• Magazine of the Korean Society of Agricultural Engineers
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• v.42 no.1
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• pp.105-112
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• 2000

This paper deals with the free vibrations of columns immersed in fluid. The column model is based on the classical Bernoulli-euler theory which neblects the effects of rotatory inerital and shear deformation. The eccentricity and rotatory inertial of the concentrated mass at the top are taken into accuont. In the governing equation for the free vibration of column, thedensity of immersed part was midified to account for theadded fluid mass. The govering differential equations are solved numerically using the corresponding boundary conditions. The lowest four natural frequencies and corresponding mode shapes are calculated over a range of non-dimensional system parameters ; the mas density ration of fluid to column, the ratio of fluid depth to span length, the ratio of tip mass to total column mass, the dimensionless mass moment of inertia, and the eccentricity.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.50-53
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• 2008

The differential equations governing free vibrations of the elastic arches with rectangular hollow section are derived in polar coordinates, in which the effect of rotatory inertia is included. Natural frequencies is computed numerically for circular arches with both clamped ends and both hinged ends. The lowest four natural frequency parameters are reported, with the rotatory inertia, as functions of three non-dimensional system parameters: the breadth ratio, the thickness ratio and the shape ratio.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.394.2-394
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• 2002

The differential equations governing free vibrations of the elastic arches with unsymmetric axis are derived in the rectangular coordinates rather than in polar coordinates, in which the effect of rotatory inertia is included. Frequencies and mode shapes are computed numerically for parabolic arches with both clamped ends and both hinged ends. Comparisons of natural frequencies between this study and SAP 2000 are made to validate theories and numerical methods developed herein. (omitted)

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.395.1-395
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• 2002

The ordinary differential equations governing free vibrations of elastic horizontally curved beams are derived, in which the effect of shear deformation as well as the effects of vertical deflection, rotatory and torsional inertias are included. Frequencies and mode shapes are computed numerically fer parabolic curved beams with hinged-hinged, hinged-clamped and clamped-clamped ends. Comparisons of natural frequencies between this study and ADINA are made to validate the theories and numerical methods developed herein. (omitted)

• Journal of the Computational Structural Engineering Institute of Korea
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• v.14 no.1
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• pp.35-42
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• 2001

본 연구는 변화곡률 수평 곡선보의 면외 자유진동에 관한 연구이다. 뒴과 회전관성을 고려한 변화곡률 수평 곡선보의 자유진동을 지배하는 상미분방정식이 유도되었고, 이 지배미분방정식을 수치해석하여 곡선보의 고유진동수를 산출하였다. 지배미분방정식을 수치적분하기 위하여 Runge-Kutta method를 이용하였고, 고유진동수를 산출하기 위하여 Regula-Falsi method와 결합한 행렬값 탐사법을 이용하였다. 본 연구의 이론적 타당성을 검증하기 위하여 타문헌의 고유진동수와 비교하였고, 실험실 규모의 모형실험을 실시하여 이론값과 실험값의 고유진동수를 비교하였다. 수치해석의 결과로 무차원 재변수들의 변화에 따른 무차원 고유진동수를 제 3모드까지 산출하였고, 그 결과들을 고찰하였다. 본 연구의 결과는 곡선형 교량 등과 같이 곡선부재로 이루어진 구조물의 설계시에 유용하게 이용될 수 있을 것으로 기대된다.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2000.11a
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• pp.202-206
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• 2000

본 연구에서는 회전 자극기를 이용하여 성별에 따른 회전 평형감각 특성을 분석하였다. 피검자는 정상성인 남녀 각각 10명에 대해, 두부회전과 rotatory chair test(RCT)에 의한 회전자극 전과 후의 변화정도를 살펴보았고, COP, Flicker Test, 적외선 카메라를 이용한 체열 측정 등을 통해 전정자극 특성을 평가하였다. 그 결과 COP를 통한 신체동요도 측정 결과 회전자극 제시 후 두부회전의 경우 총 누적거리가 1.47배, RCT의 경우 1.78배까지 증가했고, 플리커 치는 여성(8.6%)이 남성(5%)보다 높게 나타났고, 여성이 남성보다 회전자극에 민감함을 알 수 있었다. 또한, 남녀 모두 회전 자극 후 눈 주위의 온도상승이 미소하게 일어남을 알 수 있었다.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.2
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• pp.215-223
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• 2008

The differential equations governing free vibrations of the elastic arches with hollow section are derived in polar coordinates, in which the effect of rotatory inertia is included. Natural frequencies is computed numerically for parabolic arches with both clamped ends and both hinged ends. Comparisons of natural frequencies between this study and reference are made to validate theories and numerical methods developed herein. The lowest four natural frequency parameters are reported, with the rotatory inertia, as functions of three non-dimensional system parameters: the breadth ratio, the thickness ratio and the rise to span length ratio.