• Title/Summary/Keyword: inertia

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Analysis of Beam-Column Connection (Beam-Column 연결부(連結部)의 해석(解析))

  • S.J.,Yim;H.J.,Yang
    • Bulletin of the Society of Naval Architects of Korea
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    • v.14 no.4
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    • pp.3-14
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    • 1977
  • There are many Beam-Column connections in general structures and ship structures. For simplicity and convenience of analysis, the connections are mostly considered hinged when not reinforced or rigidly fixed when reinforced. This paper has intended to analyze the Beam-Column connection which is assumed two dimensional flat plate. The analysis has been preformed by Finite Element Method following the change of moment of inertia at connection. The conclusion of this investigation is as follows: By reinforcing or increasing the moment of inertia at connection part, the stress distribution of whole structure and the stress concentration at that part are relieved. Displacements of beam(when column is fixed) are almost linearly decreasing by the change of moment of inertia at connection.

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An Analysis for Turbulent Hybrid Bearings with Fluid Inertia and Swirl Injection Effects (유체의 관성력과 스월의 영향을 고려한 난류 하이브리드 베어링의 해석)

  • 이용복;김창호;최동훈
    • Tribology and Lubricants
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    • v.12 no.3
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    • pp.85-91
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    • 1996
  • An analysis for turbulent hybrid beatings with fluid inertia and swirl injection effect was derived for studying static characteristics of swirl-controlled hybrid journal. The swirl-controlled hybrid journal beating is considered to have more freedom in stability control in high speed rotating machinery. Current analysis is compared with experimental results with 3-recess hydrostatic journal bearing. The analysis revealed that the fluid momentum exchange at orifice discharge could produce pressure rise inside the recess region which can control the shear flow induced by journal rotation. The analysis also shows that the swirl-controlled hybrid journal beating has a capability of controlling load carrying capacity and stability by manipulating supply pressure and injection angle.

Optimal Switching Parameter Control of Semi-Active Engine Mount

  • Truong, Thanh Quoc;Ahn, Young-Kong;Ahn, Kyoung-Kwan
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.1-4
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    • 2005
  • This paper describes work on isolation of vibration related engine by a hydraulic engine mount with controllable area of inertia track. Automotive engine mounts are required to constrain motion of engine shake resulting from low-frequency road input of shock excitation and also to isolate noise and vibration generated by the engine with unbalanced disturbance at the high frequency range. The property of the mount depends on vibration amplitude and excitation frequency, which means that the excitation amplitude is large in low excitation frequency range and small in high frequency range. In this paper, theoretical works with model of the mount to reduce vibrations related engine were conducted. The volumetric stiffness of the mount is greatly changed according to the switching the area of the inertia track. Therefore, when the area of the inertia track is tuned, the transmissibility of the mount is effectively reduced.

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Dynamic Stability of a Drum-Brake Pad Considering Rotary Inertia and Shear Deformation (회전광성과 전단변형을 고려한 드럼-브레이크 패드의 동적안정성)

  • 오부진;공용식;류봉조;이규섭;임경빈
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.181-185
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    • 2001
  • This paper deals with the dynamic stability of a disc brake pad taking into account of its shear deformation and rotary inertia. A brake pad can be modeled as a beam like model subjected to distributed friction forces and having two translational springs. The study of this model is intended to provide a fundamental understanding of dynamic stability of drum brake pad. Governing equations of motion are derived from extended Hamilton's principle and their corresponding numerical solutions are obtained by applying the finite element formulation. The critical distributed friction force and the instability types are investigated bt changing two translational spring constants, rotary inertia parameter and shear deformation parameter. Also, the changes of eigen-frequencies of a beam determining instability types are investigated for various combinations of two translational spring constants.

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On behavior of settling heavy particles in isotropic turbulence (등방성 난류에서 침강하는 무거운 입자의 거동)

  • Jung, Jae-Dal;Yeo, Kyoung-Min;Lee, Chang-Hoon
    • 유체기계공업학회:학술대회논문집
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    • 2006.08a
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    • pp.437-440
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    • 2006
  • Particle suspension is frequently observed in many natural flows such as in the atmosphere and the ocean as well as in various engineering flows. Recently, airborne micro or nano-scale particles in atmosphere attract much attention from environmental society since small particle cause serious environmental problems in the industrialized areas. Also, the characteristics of such heavy particles' behavior is quite different from its fluid particles because the inertia force and buoyance force acting on the heavy particles are different than those acting on fluid particles. Therefore, our studies is to investigate the characteristics of the behavior of heavy particles considering the inertia effect with or without gravity effect, but do not consider modification of turbulence by the particles, that is one-way interaction. We carried out direct numerical simulation of isotropic turbulence with particles under the Stokes drag assumption for a spherical particle. These results can be used in the development of a stochastic model for predicting particle's behavior.

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Simulation using bond graphs for a hydraulic system driving large rotational inertia

  • Lee, Kyo-Il;Choi, Hoon
    • 제어로봇시스템학회:학술대회논문집
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    • 1988.10b
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    • pp.921-927
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    • 1988
  • The process and results of computer simulation using bond graphs for a hydraulic system driving large rotational inertia are presented in this paper. As the large rotational inertia and its application characteristics, control criteria of this system is not position-control nor velocity-control but appropriate acceleration, deceleration and inching ability. All the components' nonlinear characteristics are modelled using bond graphs. The equationing and solution process is carried out by a package. Finally it is concluded that modelling of this kind of system by bond graphs and using a software as its solver shows good approximated results to actual experimental data, and that the proposed modelling may be useful to actual design process for this kind of hydraulic system.

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Effects of the Longitudinal Inertia Force on Timoshenko Beam Vibration (Timoshenko 보의 진동에 미치는 축방향관성력의 영향에 관하여)

  • ;Lee, Nack Joo
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.2 no.3
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    • pp.62-68
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    • 1978
  • The influences of the large amplitude free vibrations of simply supported Timoshenko beams with ends restrained to remain a fixed distance apart and with no axial restraints, which cause a longitudinal elastic force and a longitudinal inertia force, respectively, are investigated. The equations of motion derived by an appropriate linearizarion of the nonlinear strain- displacement relation have nonlinear terms arising from large curvature, longitudinal elastic force and longitudinal inertia force. The fourth order nonlinear partial differential equations for the deflection, can be reduced to the nonlinear ordinary differential equations by means of Galerkin procedure and a modal expansion. The general response and frequensy-amplitude relations are derived by the perturbation method of strained parameters. Comparison with previously published results is made.

Analysis of influence factors on the seismic earth pressure acting on gravity walls (중력식 옹벽에 작용하는 배면 동적 토력의 영향 인자 분석)

  • 윤석재;김성렬;김명모
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2002.09a
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    • pp.75-82
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    • 2002
  • The Mononobe-Okabe method is generally used to evaluate the dynamic earth force for the seismic design of retaining walls. However, the Mononobe-Okabe method does not consider the effects of the dynamic interactions between the backfill soil and the wall. In fact, a phase difference exists between the inertia force and the seismic earth pressure. In this study, shaking table tests were peformed on gravity walls retaining dry backfill sand to analyze the influence of several parameters (the unit weight of the wall, the input acceleration and base friction) on the development of the seismic earth pressure. The experiments revealed that the magnitude of the inertia force mobilized during seismic loading affected the seismic earth pressure. The difference in the phase angles between the inertia force and the seismic earth pressure was retained at 180 degrees before the wall failed but its magnitude changed significantly as the wall began to fail.

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Free Vibration Analysis of Stepped Parabolic Arches with Timoshenko's Theory (Timoshenko 이론에 의한 불연속 변단면 포물선 아치의 자유진동 해석)

  • 오상진;진태기;모정만
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.05a
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    • pp.942-947
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    • 2004
  • The differential equations governing free, in-plane vibrations of stepped non-circuiar arches are derived as nondimensional forms including the effects of rotatory inertia, shear deformation and axial deformation. The governing equations are solved numerically to obtain frequencies and mode shapes. The lowest four natural frequencies and mode shapes are calculated for the stepped parabolic arches with hinged-hinged, hinged-clamped, and clamped-clamped end constraints. A wide range of arch rise to span length ratios, slenderness ratios, section ratios, and discontinuous sector ratios are considered. The effect of rotatory inertia and shear deformation on natural frequencies is reported. Typical mode shapes of vibrating arches are also presented.

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Modeling and Vibration Analysis of Rotating Cantilever Deams Considering Shear and Rotary Inertia Effects (전단 및 단면 관성효과를 고려한 회전 외팔보의 모델링 및 진동해석)

  • 신상하;유홍희
    • Journal of KSNVE
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    • v.6 no.2
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    • pp.179-185
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    • 1996
  • This paper presents a modeling method for the vibration analysis of a rotating beam the slenderness ratio of which is relatively small. The smaller the slenderness ratio becomes, the larger the shear and rotary inertia effects become. Such effects become critical for the accurate estimation of the natural frequencies and modeshapes, especially higher frequencies and modes, as the angular speed increases. It is also shown that the effects are important for the accurate estimation of the critical angular speed of the beam.

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