• 제목/요약/키워드: Coupled Beam

검색결과 656건 처리시간 0.023초

수동적층보의 스펙트럴요소 해석 (Spectral Element Analysis of a PCLD beam)

  • 유성준;이우식
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2007년도 정기 학술대회 논문집
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    • pp.619-624
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    • 2007
  • Spectral element method (SEM) is introduced for the fully coupled structural dynamic problems, In this paper, the beam with passive constrained layered damping (PCLD) treatments is considered as a representative problems. The beam consists of a viscoelastic layer that is sandwiched between the base beam structure and an elastic layer, The fully coupled equations of motion for a PCLD beam are derived, The equations of motion are derived first by using Hamilton's principle, From this equations of motion, the spectral element is formulated for the vibration analysis by use of the SEM, As an illustrative example, a cantilevered beam is considered. It is shown that, as the thickness of VEM layer vanishes, the results become a simple layer beam's that.

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Effect of the height of SCSW on the optimal position of the stiffening beam considering axial force effect

  • Azar, B. Farahmand;Hadidi, A.;Khosravi, H.
    • Structural Engineering and Mechanics
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    • 제41권2호
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    • pp.299-312
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    • 2012
  • Stiffened coupled shear walls (SCSW) are under axial load resulting from their weight and this axial load affects the behavior of walls because of their excessive height. In this paper, based on the continuum approach, the optimal position of the stiffening beam on the stiffened coupled shear walls is investigated considering the effect of uniformly distributed axial loads. Moreover, the effect of the height of stiffened coupled shear walls on the optimal position of the stiffening beam has been studied with and without considering the axial force effect. A computer program has been developed in MATLAB and numerical examples have been solved to demonstrate the reliability of this method. The effects of the various flexural rigidities of the stiffening beam on the internal forces and the lateral deflection of the structure considering axial force effect have also been investigated.

중주파수 대역 해석을 위한 Beam-plate-beam 연성 구조물의 웨이브 모형 연구와 시험적 규명 (Wave Models and Experimental Studies of Beam-plate-beam Coupled Systems for a Mid-frequency Analysis)

  • 유지우
    • 한국소음진동공학회논문집
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    • 제17권2호
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    • pp.121-129
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    • 2007
  • There has been much effort to find suitable methods for structural analysis in the mid-frequency region where traditional low frequency methods have increasing uncertainties whilst statistical energy analysis is not strictly applicable. Systems consisting of relatively stiff beams coupled to flexible plates have a particularly broad mid-frequency region where the beams support only a few modes whilst the plate has a high modal density and modal overlap. A system of two parallel beams coupled to a plate is investigated based on the wave method, which is an approximate method. Muller's method is utilised for obtaining complex roots of a dispersion wave equation, which does not converge in the conventional wave method based on a simple iteration. The wave model is extended from a single-beam-plate system, to a plate with two identical beams which is modelled using a symmetric-antisymmetric technique. The important hypothesis that the coupled beam wavenumber is sufficiently smaller than the plate free wavenumber is experimentally verified. Finally, experimental results such as powers and energy ratios show the validity of the analytical wave models.

크랙을 가진 L형 단면 보의 횡-비틀림 연성진동 해석 (Coupled Bending and Torsional Vibrations Analysis of Cracked L-shaped Beam)

  • 손인수;김창호;조정래
    • 한국기계가공학회지
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    • 제10권4호
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    • pp.8-15
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    • 2011
  • In this paper, the influence of a crack on the natural frequency of cracked cantilever L-shaped beam with coupled bending and torsional vibrations by analytically and experimentally is analyzed. The L-shaped beam with a crack is modeled by Hamilton's principle with consideration of bending and torsional energy. The two coupled governing differential equations are reduced to one sixth-order ordinary differential equation in terms of the flexural displacement. The crack is assumed to be in the first, second and third mode of fracture and to be always opened during the vibrations. The theoretical results are validated by a comparison with experimental measurements. The maximal difference between the theoretical results and experimental measurements of the natural frequency is less than 7.5% in the second vibration mode.

복합재 티모센코 보의 굽힘 비틀림 연성 진동에 대한 엄밀해 (Exact Solutions for Bending-Torsion Coupled Vibration of Composite Timoshenko Beam)

  • 홍성욱;강병식;박중윤
    • 대한기계학회논문집A
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    • 제25권10호
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    • pp.1559-1566
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    • 2001
  • This paper proposes a dynamic analysis method for obtaining exact solutions of composite Timoshenko beams, which are inherently subjected to both the bending , and torsional vibrations. In this paper, the bending-torsion coupled vibration of composite Timoshenko beam is rigorously modelled and analyzed. Two numerical examples are provided to validate and illustrate the bending-torsion coupled vibration of composite Timoshenko beam structure. The numerical examples prove that the proposed method is of great use for the dynamic analysis of dynamic structures composed of multiply connected composite Timoshenko beams.

3D thermo-hydro-mechanical coupled discrete beam lattice model of saturated poro-plastic medium

  • Hadzalic, Emina;Ibrahimbegovic, Adnan;Dolarevic, Samir
    • Coupled systems mechanics
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    • 제9권2호
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    • pp.125-145
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    • 2020
  • In this paper, we present a 3D thermo-hydro-mechanical coupled discrete beam lattice model of structure built of the nonisothermal saturated poro-plastic medium subjected to mechanical loads and nonstationary heat transfer conditions. The proposed model is based on Voronoi cell representation of the domain with cohesive links represented as inelastic Timoshenko beam finite elements enhanced with additional kinematics in terms of embedded strong discontinuities in axial and both transverse directions. The enhanced Timoshenko beam finite element is capable of modeling crack formation in mode I, mode II and mode III. Mode I relates to crack opening, mode II relates to in-plane crack sliding, and mode III relates to the out-of-plane shear sliding. The pore fluid flow and heat flow in the proposed model are governed by Darcy's law and Fourier's law for heat conduction, respectively. The pore pressure field and temperature field are approximated with linear tetrahedral finite elements. By exploiting nodal point quadrature rule for numerical integration on tetrahedral finite elements and duality property between Voronoi diagram and Delaunay tetrahedralization, the numerical implementation of the coupling results with additional pore pressure and temperature degrees of freedom placed at each node of a Timoshenko beam finite element. The results of several numerical simulations are presented and discussed.

Mode localization and frequency loci veering in a disordered coupled beam system

  • Lu, Z.R.;Liu, J.K.;Huang, M.
    • Structural Engineering and Mechanics
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    • 제24권4호
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    • pp.493-508
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    • 2006
  • Vibration mode localization and frequency loci veering in disordered coupled beam system are studied in this paper using finite element analysis. Two beams coupled with transverse and rotational springs are examined. Small disorders in the physical parameters such as Young's modulus, mass density or span length of the substructure are introduced in the investigation of the mode localization and frequency loci veering phenomena. The effect of disorder in the elastic support on the mode localization phenomenon is also discussed. It is found that an asymmetric disorder in the weakly coupled system will lead to the occurrence of mode localization and frequency loci phenomena.

주행 중 차륜의 연성 진동 해석 (Analysis of the Coupled Vibration for Traveling Wheel)

  • 류윤선
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 1997년도 추계학술대회논문집; 한국과학기술회관; 6 Nov. 1997
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    • pp.352-357
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    • 1997
  • The coupled vibration of a wheel-railway track system has been considered as that of a moving mass on a beam. In this paper, an analytical model is proposed to analyze the coupled vibration when a wheel travels on a railway track. The railway track supported by sleepers is considered as a beam on Winkler's foundations, and the wheel traveling on railway track at constant speed is considered as a moving mass. Hertz's contact stiffness is assumed between the wheel and railway track. Numerical results are compared with experimental ones to verify the validity of the numerical method. The numerical method in found to be efficient to analyze this system. Based on the numerical simulation, the appropriate analysis range of the beam model and the characteristics of coupled vibration are discussed.

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유도결합 플라즈마를 이용한 집속이온빔용 고휘도 이온원의 개발 및 특성연구 (Development and characteristic study of high brightness ion source using inductively coupled plasma for focused ion beam)

  • Kim, Yoon-Jae;Park, Dong-Hee;Hwang, Yong-Seok
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2004년도 춘계학술대회 논문집
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    • pp.494-499
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    • 2004
  • A ion source using inductively coupled plasma has been tested in order to test its feasibility as a high brightness ion source for focused ion beam. When operating the ion source with filter magentas in front of plasma electrode for a negative ion source, lower remittances are expected. Extracted beam remittances are measured with an Allison-type scanning device for various plasma parameters and extraction conditions. The normalized omittance has been measured to be around 0.2$\pi$mmmrad with beam currents of up to 0.55 ㎃. In particular, noting that multicusp magnets have a role in decreasing the remittance as well as increasing plasma discharge efficiency, transverse magnetic field has been confirmed to be a useful tool fur decreasing remittance via electron energy control.

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CTBA Tubular Beam의 열간 성형해석 및 실험 (Hot Stamping Simulations and Experiments for CTBA Tubular Beams)

  • 서창희;김우성;성지현;박종규;김용식;김영석
    • 소성∙가공
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    • 제24권1호
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    • pp.13-19
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    • 2015
  • For an accurate analysis of hot stamping, a coupled simulation with different aspects of the process(i.e. mechanical, thermal, and phase transformation) is needed. However, coupled simulations are time consuming and costly. Therefore, the current study proposes a simplified method focused on the forming for the hot stamping simulation of a coupled torsion beam axle (CTBA) tubular beam. In this simplified method, non-isothermal conditions were assumed and only conduction was considered, since it represents the majority of the heat transfer during hot stamping. In addition, temperature and strain rate effects were also included. Moreover, an isothermal simulation was conducted and compared with a non-isothermal simulation. Finally, the simulations were verified by experiments. In conclusion, the proposed method is shown to be effective for the development of tube-type parts, and it effectively predicts the deformation of the tubular beam during hot stamping.