말단질량 의 관성모우멘트 가 Beck's Column 의 안정성 에 미치는 영향

윤한익,김광식 대한기계학회 1984 대한기계학회논문집 Vol.8 No.2

본 논문에서는 자유단에 부착된 질량의 관성모우멘트가 Beck's column의 안정 성에 미치는 영향을 연구하였다. An analysis is presented for the vibration and stability of Beck's column carring a tip mass at its free and subjected there to a follower compressive force by using variational approach. The influence of transverse shear deformation and rotatory inertial of the mass of the column upon the critical flutter load and frequency is considered, and Timoshenko's shear coefficient K' is calculated by Cowper's formulae. It is, moreover, worth noticing that the influence of inertial moment of tip mass upon the flutter load and frequency is investigated. The centroid of a tip mass is offset from the free end of the beam and located along its extended axis of the two cases, one of which has a tip mass increasing as .xi., the tip mass offset parameter, is augmented, the other has a tip mass constant but the inertial moment is variable according to a magnitude of .eta., the tip mass offset parament. This study reveals that the effects of inertial moment of a tip mass and larger value of P are specially remarkable even a tip mass is a same.

회전하는 유체이송 외팔 파이프의 동특성 해석

윤한익,손인수 한국소음진동공학회 2003 한국소음진동공학회 논문집 Vol.13 No.1

The vibrational system of this study is consisted of a rotating cantilever pipe and the flow in the pipe. The equation of motion is derived by using Lagrange equation. The influences of the rotating angular velocity and the velocities of fluid flow in the pipe have been studied on the dynamic characteristics of a rotating cantilever pipe by numerical method. The tip-amplitude of axial vibration and maximum tip-deflection of axial direction of cantilever pipe are directly proportional to the velocity of fluid and rotating angular velocity of pipe In the steady state. respectively The bending tip-amplitude of cantilever pipe is inversely proportional to the velocity of fluid in the steady state. When the rotating angular velocity is 5 rad/s, the velocity of fluid increase with increasing the natural frequency of axial vibration at second mode and third mode, but the natural frequency axial direction of first mode is decreased. The natural frequency of lateral direction is decreased due to increase of the rotating angular velocity. It identifies that the Influence of velocity of fluid give much variation lower mode of vibration in lateral direction. And the Influence of velocity of fluid give much variation higher mode of vibration in axial direction.

이동질량을 가진 유체유동 외팔 파이프의 동특성

윤한익,손인수 한국소음진동공학회 2002 한국소음진동공학회 논문집 Vol.12 No.7

The vibrational system of this study is consisted of a cantilever pipe conveying fluid. the moving mass upon it and an attacked tip mass. The equation of motion is derived by using Lagrange equation. The influences of the velocity and the inertia force of the moving mass and the velocities of fluid flow in the pipe haute been studied on the dynamic behavior of a cantilever pipe by numerical method. As the velocity of the moving mass increases, the deflection of cantilever pipe conveying fluid is decreased. Increasing of the velocity of fluid flow make the amplitude of cantilever pipe conveying fluid decrease. The deflection of the cantilever pipe conveying fluid is increased by moving masses. After the moving mass passed upon the cantilever pipe, the amplitude of pipe is influenced due to the deflection of pipe tilth the effect of moving mass and gravity.

이동질량들을 가진 단순지지된 유체유동 파이프의 동특성

윤한익,임순홍 한국소음진동공학회 2002 한국소음진동공학회 논문집 Vol.12 No.2

A simply supported pipe conveying fluid and the moving masses upon it constitute this vibrational system. The equation of motion is derived by using Lagrange's equation. The influence of the velocity and the inertia force of the moving masses and the velocities of fluid flow in the pipe have been studied on the dynamic behavior of a simply supported pipw by numerical method. The velocities of fluid flow are considered within its critical values of the simply supported pipe without the moving masses upon it. Their coupling effects on the transverse vibration of a simply supported pipe are inspected too. The dynamic deflection of the simply supported pipe conveying fluid is increased by a coupling of the moving masses and the velocities of the moving masses and the fluid flow. When four or five regular interval masses move on the simply supported pipe conveying fluid, the amplitude of the simply supported pipe conveying fluid is small at low velocity of the masses, but at high velocity of the masses the deflection of midspan of the pipe is increased by coupling with the numbers and magnitude of the masses. The time which produce the maximum dynamic deflection of the simply supported pipe is delayed according to the increment of the number of moving masses.

크랙과 이동질량을 가진 유체유동 파이프의 동특성 해석

윤한익 한국소음진동공학회 2004 한국소음진동공학회 학술대회논문집 Vol.2004 No.11

초기 변위를 가지고 연속 이동하는 스프링-질량계가 등분포종동력을 받는 단순지지보의 동특성에 미치는 영향

윤한익,강혁준,유진석 한국소음진동공학회 2003 한국소음진동공학회 논문집 Vol.13 No.3

A simply supported beam subjected to a uniformly distributed tangential follower force and the two successively moving spring-mass systems upon it constitute this vibration system. The influences of the velocities of the moving spring-mass system, the distance between two successively moving spring-mass systems and the uniformly distributed tangential follower force have been studied on the dynamic behavior of a simply supported beam by numerical method. The uniformly distributed tangential follower force is considered within its critical value of a simply supported beam without two successively moving spring-mass systems, and three kinds of constant velocities and constant initial displacement of two successively moving spring-mass systems are also chosen. Their coupling effects on the transverse vibration of the simply supported beam are inspected too. In this study the simply supported beam is deflected with small vibration proportional to natural frequency of the moving spring-mass systems. According to the increasing of initial displacement of the moving spring-mass systems the amplitude of the small vibration of the simply supported beam is increased due to the spring force. The velocity of the moving spring-mass system more affect on the transverse deflection of simply supported beam than other factors of the system and the effect is dominant at high velocity of the moving spring-mass systems.

유체유동 외팔 파이프의 고유진동수에 미치는 이동질량들의 영향

윤한익,손인수,진종태,김현수 한국소음진동공학회 2002 한국소음진동공학회 논문집 Vol.12 No.11

The vibrational system of this study is consisted of a cantilever pipe conveying fluid, the moving masses upon it and an attached tip mass. The equation of motion is derived by using Lagrange equation. The influences of the velocity and the number of moving masses and the velocities of fluid flow in the pipe have been studied on the natural frequency of a cantilever pipe by numerical method. As the size and number of a moving mass increases, the natural frequency of cantilever pipe conveying fluid is decreased. When the first a moving mass Is located at the end of cantilever pipe, the increasing of the distance of moving masses make the natural frequency increase at first and third mode, but the frequency of second mode is decreased. The variation of natural frequency of the system is decreased due to increase of the number of a moving mass. The number and distance of moving masses effect more on the frequency of higher mode of vibration

固定端 의 스프링 상수 가 末端質量을 가진 Beck′s Column 의 安定性 에 미치는 영향

윤한익,김광식 대한기계학회 1985 대한기계학회논문집 Vol.9 No.5

본 논문에서는 전보의 연속으로서 말단질량이 부착된 기둥의 자유단에 압축 종동력이 작용하는 비보존적 탄성계의 불완전 고정단에 나타나는 스프링 특성의 영향 을 연구하였다. 고정단은 병진스프링과 회전스프링으로 구속되었고, 이들 스프링 상 수의 여러 값이 말단질량과 연성(coupling)되어 기둥의 안정성에 미치는 영향을 연구 하였다. 기둥의 전단변형과 회전관성의 영향을 고려하였으며, Hamilton's principle 로서 계의 운동방정식과 경계조건의 식을 유도하여 수치해석하였다. On the stability of the Beck's column with a tip mass, the influence of the characteristics of the springs at the fixed end of the column are studied. The equations of motion and boundary conditions of this system are established by using the Hamiton's principle. On the evaluation of the stability of the column, t he effect of the shear deformation and rotatory inertial is considered in calculation. For the maintenance of the stability of the column, it is proved that the constant of the translational spring at the fixed end must be very large while th magnitude of the constant of the rotational spring at the fixed end has no effect. When the constants of the springs at the fixed end are small, it is also proved that the influence of the moment of inertial of the tip mass on the stability of the column are decreased and for the translational spring the degree of the decrease is more and more. Therefore it is found that the characteristics of the springs at the fixed end are very effective elements for the stability of the column when the columns subjected to a compressive follower force are designed.

유체유동을 갖는 회전 외팔 파이프의 동특성에 미치는 끝단질량의 영향

윤한익,최창수,손인수 대한기계학회 2003 大韓機械學會論文集A Vol.27 No.11

유체유동을 갖는 외팔 파이프의 동특성 및 진동수에 미치는 설계인자의 영향

윤한익,손인수,박일주 대한기계학회 2003 大韓機械學會論文集A Vol.27 No.11