• 제목/요약/키워드: Deflection Analysis

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Deflection of battened beams with shear and discrete effects

  • Li, Ji-liang;Chen, Jian-kang
    • Structural Engineering and Mechanics
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    • 제59권5호
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    • pp.921-932
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    • 2016
  • This paper presents a theoretical analysis for determining the transverse deflection of simply supported battened beams subjected to a uniformly distributed transverse quasi-static load. The analysis considers not only the shear effect but also the discrete effect of battens on the transverse deflection of the battened beam. The analytical solution is obtained using the principle of minimum potential energy. Numerical validation of the present analytical solution is accomplished using finite element methods. The present analytical solution shows that the shear effect on the transverse deflection of battened beams increases with the cross-section area of the main member but decreases with the cross-section area of the batten. The longer the battened beam is, or the larger the moment of inertia of the main member is, the smaller the shear effect will be.

고차전단변형과 대처짐을 고려한 복합적층판의 저속충격거동 해석 (Low-Velocity Impact Response Analysis of Composite Laminates Considering Higher Order Shear Deformation and Large Deflection)

  • 최익현;홍창선
    • 대한기계학회논문집
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    • 제17권12호
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    • pp.2982-2994
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    • 1993
  • Low-velocity impact responses of composite laminates are investigated using the finite element method based on various theories. In two-dimensional nonlinear analysis, a displacement field considering higher order shear deformation and large deflection of the laminate is assumed and a finite element formulation is developed using a C$^{o}$-continuous 9-node plate element. Also, three-dimensional linear analysis based on the infinitesimal strain-displacement assumptions is performed using 8-node brick elements with incompatible modes. A modified Hertzian contact law is incorporated into the finite element program to evaluate the impact force. In the time integration, the Newmark constant acceleration algorithm is used in conjuction with successive iterations within each time step. Numerical results from static analysis as well as the impact response analysis are presented including impact force histories, deflections, strains in the laminate. Impact responses according to two typical low-velocity impact conditions are compared each other.

Aeroelastic Characteri stics of Rotor Blades with Trailing Edge Flaps

  • Lim, In-Gyu;Lee, In
    • International Journal of Aeronautical and Space Sciences
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    • 제8권1호
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    • pp.115-121
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    • 2007
  • The aeroelastic analysis of rotor blades with trailing edge flaps, focused on reducing vibration while minimizing control effort, are investigated using large deflection-type beam theory in forward flight. The rotor blade aerodynamic forces are calculated using two-dimensional quasi-steady strip theory. For the analysis of forward flight, the nonlinear periodic blade steady response is obtained by integrating the full finite element equation in time through a coupled trim procedure with a vehicle trim. The objective function, which includes vibratory hub loads and active flap control inputs, is minimized by an optimal control process. Numerical simulations are performed for the steady-state forward flight of various advance ratios. Also, numerical results of the steady blade and flap deflections, and the vibratory hub loads are presented for various advance ratios and are compared with the previously published analysis results obtained from modal analysis based on a moderate deflection-type beam theory.

ODS 해석에 의한 ATM 케이스 진동 저감 (Operation Deflection Shapes Analysis for Vibration Reduction of ATM Case)

  • 신범식;이승목;김도현;최연선
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2006년도 춘계학술대회논문집
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    • pp.232-237
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    • 2006
  • Operation deflection shapes(ODS) is defined as a motion of structure at particular frequency. The ODS is eligible to show any types of structural motions while the modes supply solutions only to linear and stationary motion. The principal vibration source of an auto teller machine(ATM) case was occurred due to resonance which was found by modal analysis. To reduce the vibration of ATM case, the motion of the case was visualized using ODS analysis, which can suggest how to modify the structure. As a result the vibration of the ATM case was greatly reduced with a stiffening bar between the opposite plates.

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Nonlinear bending analysis of functionally graded CNT-reinforced composite plates

  • Cho, Jin-Rae
    • Steel and Composite Structures
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    • 제42권1호
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    • pp.23-32
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    • 2022
  • In this paper, a nonlinear numerical method to solve the large deflection problem is introduced. And the non-dimensional load-deflection behavior of functionally graded carbon nanotube-reinforced composite (FG-CNTRC) plates is parametrically investigated. The large deflection problem is formulated according to the von Kármán nonlinear theory and the (1,1,0)* hierarchical model, and it is approximated by 2-D natural element method (NEM). The shear locking phenomenon is suppressed by the selectively reduced integration method. The nonlinear matrix equations are solved by combining the incremental loading scheme and the Newton-Raphson iteration method. The proposed method is validated from the benchmark experiments, where the propose method shows an excellent agreement with the reference methods. The nonlinear behavior of FG-CNTRC plates is evaluated in terms of the non-dimensional load-deflection curve, and it is parametrically investigated with respect to the existence/non-existence and gradient pattern of CNTs, the width-to-thickness and aspect ratios of plates and the type of boundary conditions. The non-dimensional central deflection is significantly reduced when CNTs and added, and it decreases with the volume fraction of CNTs. But, it shows a uniform increase in proportion to the width-to-thickness and aspect ratios. Both the gradient pattern of CNTs and the type of boundary conditions do also show the remarkable effects.

유한 요소법을 이용한 붐대의 동특성 해석 (Dynamic Analysis of Boom Using Finite Element Method)

  • 한수현;김병진;홍동표;태신호
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2005년도 춘계학술대회논문집
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    • pp.987-991
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    • 2005
  • The Aerial platform Truck is widely used for work in high place with the aerial platform. The most important thing is that worker's safety and worker must be able to work with trustworthiness so it needs to be verified its stiffness, deflection of boom, and dynamic condition concerned with a rollover accident. It should have an analytical exactitude because it is directly linked with the worker safety. In this point, we are trying to develop a proper CAE analysis model concerned with a rollover safety, bending stress and deflection for load. The Aerial platform Truck have a dynamic characteristics by load and moving of boom in the work field, so its static and dynamic strength analysis, structural mechanics are very important. Therefore, we evaluate the safety of each boom to calculating its stress, deflection. A computer simulation program is used widely for doing applying calculation of stiffness and structural mechanics, then finally trying to find a optimum design of the Aerial platform Truck.

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타이백 억지토류벽에서 앵커 자유장 및 앵커하중의 크기와 벽체변위와의 상관성 (A Relation between Anchor Unbonded Length, Anchor Loads, and Wall Deflection in Tieback Anchored Wall)

  • 임유진
    • 한국지반공학회논문집
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    • 제15권6호
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    • pp.187-200
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    • 1999
  • 타이백 앵커 억지 토류벽의 거동을 분석하기위해 광범위한 현장계측자료를 조사하고 이중 한 현장에 대한 유한요소해석을 실시하였다. 특히, 임의 굴착깊이에 대한 벽체변위-앵커자유장-앵커긴장하중 사이의 상관성을 조사하였다. 유한요소해석은 앵커하중과 앵커자유장을 변화시키면서 벽체변위의 증감을 조사하기 위해 실시하였다. 굴착깊이로 정규화시킨 횡방향 벽체 변위와 앵커위치의 상관도를 작성하였으며 임의 굴착깊이에 대한 벽체변위-앵커자유장-앵커긴장하중 사이에 고유한 관계가 설정됨을 확인하였다. 차후 실무차원에서 이를 활용하기 위해서는 더 많은 현장계측자료의 집적과 유한요소해석의 추가적인 실시가 필요하다.

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