• 제목/요약/키워드: vertical motion

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Dynamic response of empty steel tanks with dome roof under vertical base motion

  • Virella, Juan C.;Godoy, Luis A.
    • Steel and Composite Structures
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    • 제9권2호
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    • pp.119-130
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    • 2009
  • This paper reports results of the structural response of empty steel tanks under vertical ground motions. The tanks are modeled using a finite element discretization using shell elements, and the vertical motion is applied and analyzed using nonlinear dynamics. Several excitation frequencies are considered, with emphasis on those that may lead to resonance of the roof. The computational results illustrate that as the base motion frequency is tuned with the frequency of the first roof-mode of the tank, the system displays large-amplitude displacements. For frequencies away from such mode, small amplitude displacements are obtained. The effect of the height of the cylinder on the dynamic response of the tank to vertical ground motion has also been investigated. The vertical acceleration of the ground motion that induces significant changes in the stiffness of the tank was found to be almost constant regardless of the height of the cylinder.

해저지진의 수직지반운동에 의한 부유식 해양구조물의 지진응답 해석기법 개발 (Analysis of Earthquake Responses of a Floating Offshore Structure Subjected to a Vertical Ground Motion)

  • 이진호;김재관;진병무
    • 한국지진공학회논문집
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    • 제18권6호
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    • pp.279-289
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    • 2014
  • Considering a rigorously fluid-structure interaction, a method for an earthquake response analysis of a floating offshore structure subjected to vertical ground motion from a seaquake is developed. Mass, damping, stiffness, and hydrostatic stiffness matrices of the floating offshore structure are obtained from a finite-element model. The sea water is assumed to be a compressible, nonviscous, ideal fluid. Hydrodynamic pressure, which is applied to the structure, from the sea water is assessed using its finite elements and transmitting boundary. Considering the fluid-structure interaction, added mass and force from the hydrodynamic pressure is obtained, which will be combined with the numerical model for the structure. Hydrodynamic pressure in a free field subjected to vertical ground motion and due to harmonic vibration of a floating massless rigid circular plate are calculated and compared with analytical solutions for verification. Using the developed method, the earthquake responses of a floating offshore structure subjected to a vertical ground motion from the seaquake is obtained. It is concluded that the earthquake responses of a floating offshore structure to vertical ground motion is severely influenced by the compressibility of sea water.

도마 Yeo동작에 대한 운동학적 요인 분석 (Kinematic Analysis of Yeo Motion at Horse Vaulting)

  • 여홍철
    • 한국운동역학회지
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    • 제13권1호
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    • pp.39-50
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    • 2003
  • The purpose of this experiment was to find out the stages of result of specific character for Horse Vaulting Yeo motion To put the Yeo movement in process, we needed a gymnastics athlete C height of 165cm, weight of 62kg, age of 32, personal history of 21 years, and tested the athlete 5 times of motion training, and picked out the 2 best motion and analyzed it. Athletic reason is vertical motion, time uses, horizontal motion, distance, speed, and analyzed many other reasons as a result, and finally ended up with this conclusion. 1. After the take off on the board horizontal speed gradually decreased However, reverse of that, it showed that vertical speed increased. 2. While contacting the Horse Vaulting, horizontal speed decreased and vertical speed kept on increasing. Taking off Com the Horse Vaulting, horizontal, showing short time of training, 3m vertical height is shown after using Yeo motion at the peak of second fly jump. 3. While contacting the Horse Vaulting, both arms were showing the flection shape Especially this is also while contacting the Horse Vaulting, left arm was showing $90^{\circ}$ angle, and this has happened between the process of transition period of fast horizontal speed to vertical speed. 4. While contacting the Horse Vaulting, perfect blocking of the left arm must be complete for the right arm to have the perfect blocking as well.

선내 위치에 따른 선박의 종운동 특성 (Longitudinal motion characteristics of a ship according to the location)

  • 강일권;김민석;박병수;홍진근;정성재;함상준
    • 수산해양기술연구
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    • 제48권2호
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    • pp.147-154
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    • 2012
  • In head sea, a ship has mainly the longitudinal motion such as vertical acceleration and pitch. In that case, the motion characteristics of a ship will have changed as the location different from each of place vertically and horizontally on board. The author carried out an experiment about the ship's vertical acceleration and pitch according to the location for the head sea, and analyzed the data with the aid of the statistical and spectral analyzing method to get the motion characteristics of the vessels. The response of vertical acceleration and pitch not deeply depend on the decks vertically, but displayed the relative big different value horizontally even if same deck. The biggest response of vertical acceleration and pitch among the accommodations was shown at scientist room, but the value of it not reached to the minimum requirement of ISO 2631-1 for working on board.

3D 프린터 기반 수직형 마이크로 모션 스테이지의 최적설계 (Optimal Design of 3D Printer based Piezo-driven Vertical Micro-positioning Stage)

  • 김정현
    • 로봇학회논문지
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    • 제12권1호
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    • pp.78-85
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    • 2017
  • This paper presents the development of a 3D printer based piezo-driven vertical micro-positioning stage. The stage consists of two flexure bridge structures which amplify and transfer the horizontal motion of the piezo-element into vertical motion of the end-effector. The stage is fabricated with ABS material using a precision 3D printer. This enables a one-body design eliminating the need for assembly, and significantly increases the freedom in design while shortening fabrication time. The design of the stage was optimized using response surface analysis method. Experimental results are presented which demonstrate 100nm stepping in the vertical out-of-plane direction. The results demonstrate the future possibilities of applying 3D printers and ABS material in fabricating linear driven motion stages.

6축 힘측정판을 이용한 수직방향 전신진동에 대한 겉보기질량 및 겉보기편심질량에 대한 고찰 (Study of Apparent Mass and Apparent Eccentric Mass to Vertical Whole-body Vibration by Using Strain-gage Type Six-axis Force Plate)

  • 전경진;김민석;안세진;정의봉;유완석
    • 한국소음진동공학회논문집
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    • 제21권10호
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    • pp.897-904
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    • 2011
  • When whole-body is exposed to vertical vibration, asymmetry shape of human body affects the response on the translational(fore-aft, lateral, vertical) and rotational(roll, pitch, yaw) motion. While the translational motion has been studied with various titles, it has been rare to study the rotational motion of human body exposed to vertical excitation because of lack of experimental equipment. This study was performed by using a 6-axis force plate installing strain gage type sensors for the rotational response. Sixteen male subjects were exposed to vertical vibration on rigid seat in order to investigate apparent mass of three translational motion and apparent eccentric mass of three rotational motion. Random signal was generated to make excitation vibration which was on an effective frequency range of 3~40 Hz, and magnitude of 0.224 m/$s^2$ r.m.s. The frequency range and magnitude used was selected for the vibration of passenger vehicle on idling condition. As the result, cross-axis apparent masses of fore-and-aft and lateral direction were not significant showing 20 % and 3 % of vertical apparent mass relatively. And apparent eccentric mass of pitch motion was dominant when compared to that of roll and yaw motion, which is reasoned by asymmetry direction of human body sitting on a seat.

상지동작에 따른 길의 변화에 관한 연구(제2보) - 사선방향의 변화를 중심으로 - (A Study on the Change of Waist Pattern by Upper Limb Motion (Part 2) - By the Change of Oblique Line -)

  • 이은정
    • 한국의류산업학회지
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    • 제4권2호
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    • pp.145-155
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    • 2002
  • In order to investigate how upper limb motion gives influence on clothing, this study measured tests by following standards: Front Vertical motion, Side-Vertical motion, and Horizontal motion. For this study, the procedures in the order of alphabet are applied. A. Eeach of testee's pattern was copied by the motion with a method of tight fitting technique. B. Analyzing each of the size-change on measuring item. C. Studying the moving aspects at each datum points. The results shows that the biggest change can be found in the following items. 1) In vertical motion of F4 (the length to shoulder point from A-point) 2) In horizontal motion of F5 (the length to front-width point from A-point), the check-result gained by checking the notice between motions shows that the most noticeable items are F4 (the length to shoulder point from A-point), F5 (the length to front-width point from A-point), F6 (the length to armpit point from A-point), B7 (the length to side-waist point from B-point). In result of the study of datum point's movement by motion, the items which were measured with the longest on straight-distance in vertical motion are the front and rear-shoulder, and the rear-shoulder, front-armpit in horizontal motion each. In the movement of each datum points by length, the check-result gained by checking the notice between motions shows that the most remarkable item is the front-shoulder.

The Horizontal Wind and Vertical Motion Field Derived from the NOAA Polar Orbiting Satellites

  • Lee, Dong-Kyou
    • 대한원격탐사학회지
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    • 제4권1호
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    • pp.41-47
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    • 1988
  • The operational NOAA satellite temperature soundings are utilized to determine the horizontal wind and vertical motion fields for a polar low case over the East Asian region by solving the nonlinear balance equation and the omega equation. Preliminary results demonstrate that the balanced wind and vertical motion fields derived from the satellite data give reasonable synoptic patterns associated with the polar low. This encourages the use of satellite information as inputs in the numerical weather prediction models.

구속받는 3차원 유연 매니퓰레이터의 컴플라이언스 해석 (Compliance Analysis of Constrained Spatial Flexible Manipulators)

  • 김진수
    • 한국공작기계학회논문집
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    • 제15권3호
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    • pp.91-96
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    • 2006
  • The aim of this paper is to clarify the structural compliance of the constrained spatial flexible manipulator and to develop the force control by using the compliance of the links. Using the dependency of elastic deflections of links on contact force, vibrations for constrained vertical motion have been suppressed successfully by controlling the position of end-effector. However, for constrained horizontal motion, the vibrations cannot be suppressed by only controlling position of end-effector. We present the experimental results for constrained vertical motion, and constrained horizontal motion. Finally, a comparison between these results is presented to show the validity of link compliance.

수직 Rayleigh 유동내의 입자 거동 해석 (Analysis for Particle Motion of Vertical Rayleigh flow)

  • 고석보;전용두;이금배
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2006년도 하계학술발표대회 논문집
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    • pp.755-760
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    • 2006
  • The exhaust gas with solid particle goes through the riser in both particle circulating type and circulating fluidized bed type heat exchanger to recover the heat. During heat transfer, gas velocity in vertical riser decreases as viscosity of exhaust gas decreases. In this case, when the particle size is fixed, sometimes the exhaust gas happens to have lower velocity which prohibit them to go out of the riser. In this paper the particle motion in vertical Rayleigh flow was studied. The behavior of heat transfer was investigated by means of velocity and temperature distribution. The result from numerical analysis was validated by the experimental results. Fortran code was used to analyze the particle motion in vertical Rayleigh flow.

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