• 제목/요약/키워드: Concentrated Mass

검색결과 357건 처리시간 0.026초

비균질 Pasternak 지반 위에 놓인 박판의 자유진동 해석 (Free Vibration Analysis of Thin Plate on Inhomogeneous Pasternak Foundation)

  • 이용수;오숙경;이효진;김일중
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2002년도 추계학술대회논문집
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    • pp.982-987
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    • 2002
  • Recently, as size of building structure becomes larger, mat area of building structure is supported on Inhomogeneous foundation. The equipment machineries in building are mostly on basement story. The slab of the lowest basement story with equipment machineries is considered as plate supported on foundation with concentrated masses. In this paper, vibration analysis of rectangular thin plate is done by use of rectangular finite element with 4 nodes. The solution of this paper are compared with existing solution and natural frequencies of thin plates, with concented mass, on inhomogeneous Pasternak foundation are calculated

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유한요소법에 의한 단순화된 미사일 몸체 모델의 안정성에 관한 연구 (A study onthe stability of a missile body ina simplified model by finite element method)

  • 박영필;김찬수
    • 대한기계학회논문집
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    • 제5권4호
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    • pp.293-302
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    • 1981
  • In this paper, the stability of a flexible missle, idealized as a free-free beam, is evaluated by using the finite element method. For the study, heavy machinery part is modeled as a concentrated mass and the thrust, which is controlled by a feedback sensor located at a predetermined position, is considered as a constant follower force. The aerodynamic forces, the structural damping, the cross sectional variation servo lag effect are neglected in this study. With unconstrained variational principle, the finite element method is applied to the nondimensionalized beam eqution. The matrix eigenvalue equation is obtained and the eigenvalues are calculated by a computer for the stability analysis. The stability is evaluated by the inspection of the eigenvalues are calculated by a computer for the stabilith analysis. The stabilith is evaluated by the inspection of the eigenvalues of the problem. For the study, the behaviors of the eigenvalues at various thrusts and the effects of the magnitudes and positions of the concentrated mass and directional control constant are analyzed.

집중 질량을 갖는 후판의 좌굴 및 진동해석 (Buckling and Vibration Analysis of Thick Plates with Concentrated Mass)

  • 김일중;오숙경;이용수
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2001년도 가을 학술발표회 논문집
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    • pp.467-474
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    • 2001
  • This paper is for the buckling and vibration analysis of thick plate with concentrated mass on a inhomogeneous pasternak foundation. A thick rectangular plate resting on a inhomogeneous pasternak foundation is isotropic, homogeneous and composite with linearly elastic material. In order to analyize plate which is supported on inhomogeneous pasternak foundation, the value of winkler foundation parameter(WFP) of centural and border zone of plate are chosen as Kwl and Kw2 respectively. The value of Kwl and Kw2 can be changed as 0, 10, 10 /sup 2/, 10 / sup 3/ and the value of SFP(shear foundation parameter) also be changed 0, 5, 10, 15 respectively. Finally, In this paper, buckling stress of rectangular plate on the inhomogeneous pasternak foundation, natural frequency of this plate with or without uniform in-plane axial stresses are calculated

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선박(船舶)의 적화상태(積貨狀態)가 선체진동(船體振動) 특성(特性)에 미치는 영향 (The Effect of Loading Conditions on Ship Vibration Characteristics)

  • 김극천;곽문규;김형만
    • 대한조선학회지
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    • 제20권1호
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    • pp.29-33
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    • 1983
  • The loading condition, of a ship, especially a multi-purpose cargo carrier, in service, is often changed. Then, the prediction of natural frequency changes is necessary to provide measures for prevention of ship vibrations. In this paper a simplified method for the above purpose is presented. The bases of the method are analytical solutions for the lateral vibrations of uniform Timoshenko beams carrying a concentrated mass and the Dunkerley's formula. In this method a ship in the standard ballast condition is reduced to a uniform Timoshenko beam having same system parameters as those of the midship section. To investigate the validity of the proposed method, numerical calculations are carried out for a 46,000 DWT bulk carrier and compared with detailed calculations based on the finite difference method. Even in cases those the cargoes in a hold, length of which is about 13% of the ship's length, are reduced to a concentrated mass, the proposed method gives results of several percent differences from the detailed calculations up to the six-noded mode.

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종동력을 받는 외팔 Timoshenko보의 동적안정성에 미치는 부분탄성기초의 영향 (Effect of a Partial Elastic Foundation on Dynamic Stability of a Cantilevered Timoshenko Beam under a Follower Force)

  • 류봉조;류시웅;한현희;김효준
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.911-916
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    • 2004
  • The paper deals with the dynamic stability of a cantilevered Timoshenko beam on partial elastic foundations subjected to a follower force. The beam is assumed to be a Timoshenko beam with a concentrated mass taking into account its rotary inertia and shear deformation. Governing equations are derived by extended Hamilton's principle, and FEM is applied to solve the discretized equation. Critical follower force depending on the attachment ratios of partial elastic foundations, concentrated mass and rotary inertia of the beam is fully investigated.

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비균질 Pasternak지반 위에 놓인 집중질량을 갖는 후판의 자유진동 (Free Vibrations of Thick Plates with Concentrated Masses on In-homogeneous Pasternak Foundation)

  • 이용수;이병구;김일중;이태은
    • 한국소음진동공학회논문집
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    • 제13권4호
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    • pp.281-289
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    • 2003
  • Recently, as high-rise buildings increase steeply, sub-structures of them are often supported on in-homogeneous foundation. And there are many machines in sub-structures of buildings, and slabs of sub-structures are affected by vibration which they make. This paper deals with vibration of plates with concentrated masses on in-homogeneous foundation. Machines on plates are considered as concentrated masses. In-homogeneous foundation is considered as assigning $k_{w1}$ and $k_{w2}$ to Winkler foundation parameters of central region and side region of plate respectively, and foundation is idealized to use Pasternak foundation model which considered both of Winkler foundation parameter and shear foundation parameter. In this paper, applying Winkler foundation parameters which $k_{w1}$and $k_{w2}$ are 10, $10^2$, $10^3$ and shear foundation parameter which are 10, 20 respectively, first natural frequencies of thick plates with concentrated masses on in-homogeneous foundations are calculated.

환경시료로부터 미량 페놀류의 분석을 위한 isoButoxycarbonyl 유도체화 분석방법 적용 및 최적화 (Application and Optimization of the IsoButoxycarbonyl Derivatization method to the Analysis of Trace Level Phenols in Environmental Samples)

  • 김협;홍종기;김용화;김경례
    • Environmental Analysis Health and Toxicology
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    • 제17권1호
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    • pp.37-51
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    • 2002
  • Eleven phenols including two chlorophenols, eight alkylphenols and bisphenol A were derivatized with isobutylchloroformate to form their isobutoxycarbonyl derivatives. Standard phenol mixture was concentrated for the isobutoxycarbonyl (isoBOC) derivatization and analysed by gas chromatography/mass spectrometry (GC/MS). The recoveries of the derivatization method of alkylphenols, chlorophenols, and bisphenol A were calculated by gas chromatography/mass spectrometry-selected ion monitoring mode using two work-up methods for comparison; shaking and heating method. The linear detector responses were obtained in the concentration range of 5∼400 ng, with correlation coefficients varying from 0.9755∼0.9981. Recoveries of the alkylphenols, chlorophenols, and bisphenol A were determined by gas chromatography/mass spectrometry-selected ion monitoring mode using two work-up methods for comparison ; the US-EPA method and the isoBOC derivatization method, Eleven phenols in water samples were extracted with dichloromethane and then concentrated. Also, solid-phase extraction (SPE) with XAD-4 and subsequent conversion to isobutoxycarbonyl derivatives for sensitive analysis with the selected ion-monitoring (SIM) mode. The recoveries were 85.1∼109.9% and 90.3∼126.6% for the US-EPA method and the isoBOC.

한국형 고속전철 차량시스템의 개념설계 (The Conceptual Design of Korea High Speed Train System)

  • 김경택;정경렬
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 1999년도 추계학술대회 논문집
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    • pp.172-180
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    • 1999
  • The major subject of this paper is to develop the concept fur a Korea high speed train system and recommend to train configuration. High speed train configurations are basically concerned traction power(train configurations with concentrated; CPT or distributed Power system: DPT) and train design(single car as compared with articulated bogies). The result of configuration, a advantages and disadvantaged were necessitated by different train configurations; -distributed underfloor power have an increased length for the seats by 15% as compared with the concentrated power trait - articulated trainsets are characterised by less of number of bogies and reduced values of mass, train resistance, noise and vibration. from the result, the optimized train concept combining high seat capacity per train length with low weight and train resistance is 400m long, single -floor train composed of two symmetrically arranged half trainsets. Therefore, at this work recommended distributed train system However, the final decision of Korea high speed train configuration was concentrated power train and articulated bogie system. The configuration of trainset was 20cars included 2 power cars, 4 motorized cars and 14 trailer cars.

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