• Title/Summary/Keyword: Beam structure

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Ground Beam Structure Based Joint Stiffness Controlling Method for Compliant Mechanisms (컴플라이언트 메커니즘 설계를 위한 바닥 보 구조 기반 조인트 강성 조절법)

  • Jang Gang-Won;Kim Yoon-Young;Kim Myung-Jin
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.30 no.10
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    • pp.1187-1193
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    • 2006
  • Traditionally, the continuum-based topology optimization methods employing the SIMP technique have been used to design compliant mechanisms. Although they have been successful, the optimized mechanisms by the methods are usually difficult to manufacture because of their geometrical complexities. The objective of this study is to develop a topology optimization method that can produce easy-to-fabricate mechanism structure. The proposed method is a ground beam method where beam connectivity is controlled by the beam joint stiffness. In this approach, beam joint stiffness determines the mechanism configuration. Because b the ground structure beams have uniform thicknesses varying only discretely, the resulting mechanism topologies become easily manufacturable.

Vibration Reduction of Beam Structure Using Squeeze Mode ER Mount (압착모드형 ER마운트를 이용한 보 구조물의 진동저감 해석)

  • 정우진;김두기;정의봉;홍성룡;최승복
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.12 no.7
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    • pp.557-564
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    • 2002
  • To reduce unwanted vibrations in war ship which may be transmitted through underwater path, it is required to use high damping mounts to isolate the vibration. In this work, the beam structure with squeeze mode ER mount is proposed and response characteristics such as acceleration and force transmissibility of beam with constant voltage and optimal controller are experimentally analyzed. The controller is empirically realized and control responses are evaluates in frequency domains. Experiments show vibration reduction capability of squeeze mode ER mount.

Dynamic Analysis of a Moving Vehicle on Flexible beam Structure (II) : Application

  • Park, Tae-Won;Park, Chan-Jong
    • International Journal of Precision Engineering and Manufacturing
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    • v.3 no.4
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    • pp.64-71
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    • 2002
  • Recently, mechanical systems such as a high-speed vehicles and railway trains moving on flexible beam structures have become a very important issue to consider. Using the general approach proposed in the first part of this paper, it is possible to predict motion of the constrained mechanical system and the elastic structure, with various kinds of foundation supporting conditions. Combined differential-algebraic equation of motion derived from both multibody dynamics theory and finite element method can be analyzed numerically using a generalized coordinate partitioning algorithm. To verify the validity of this approach, results from the simply supported elastic beam subjected to a moving load are compared with the exact solution from a reference. Finally, parametric study is conducted for a moving vehicle model on a simply supported 3-span bridge.

An Experimental Study on the Vibration Absorber for Vibration Attenuation of Cantilever Beam Structure (외팔보 구조물의 진동감쇠를 위한 동흡진기의 실험적 연구)

  • Kwag, Dong-Gi;Bae, Jae-Sung;Hwang, Jai-Hyuk;Kim, Hun-Soo
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.21 no.11
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    • pp.991-996
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    • 2011
  • This study was carried out vibration attenuation of vibration absorber attached to the cantilever beam structure. Modern tank guns are stabilized to allow fire on the move while traversing uneven terrain. However, as the length of the barrel is extended, to meet required muzzle exit velocities, the terrain induced vibrations lead to increased muzzle pointing errors. Thus, reducing these vibrations should lead to increased accuracy. The vibration absorber includes a compliant energy storage device, such as a spring, and a mass secured to the energy storage device. In this study, it accomplished a research in about gun barrel vibration attenuation using tuned mass damper. The barrel was hung from a bungee cord for free-free condition. It accomplished a vibration experiment for verified attenuation efficiency.

Shape Optimization Technique for Thin Walled Beam of Automotive Structures Considering Vibration

  • Lee, Sang-Beom;Yim, Hong-Jae;Pyun, Sung-Don
    • The Journal of the Acoustical Society of Korea
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    • v.21 no.2E
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    • pp.63-70
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    • 2002
  • In this paper, an optimization technique for thin walled beams of vehicle body structure is proposed. Stiffness of thin walled beam structure is characterized by the thickness and typical section shape of the beam structure. Approximate functions for the section properties such as area, area moment of inertia, and torsional constant are derived by using the response surface method. The approximate functions can be used for the optimal design of the vehicle body that consists of complicated thin walled beams. A passenger car body structure is optimized to demonstrate the proposed technique.

Elastic Finite Element Analysis for a Flexible Beam Structure. (유연한 보구조물의 탄성유한요소해석)

  • Jung, Dong-Won;Lim, Sae-Young
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.11
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    • pp.3441-3453
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    • 1996
  • A finite element anlaysis is performed for large deformations of a felxible beam. The total Lagrangian formulation for a general large deformation, which involves finite rotations, is chosen and the exponential map is used to treat finite rotations from the Eulerian point of view. The finite elements results are confirmed for several cases of deformations through comparison to a first order elasticity solution obtained by numerical integration, and the agreement between the two is found to be excellent. For lateral buckling, the point of vanishing determinant of the resulting unsymmetric tangent stiffness is traced to examine its relationship to bifurcation points. It is found that the points of vanishing determinant is not corresponding to bifurcation points for large deformation in general, which suggests that the present unsymmetric tangent stiffness is not an exact first derivative of internal forces with respect to displacement.

Vibration Reduction of Beam Structure using Squeeze Mode ER Mount (압착모드형 ER 마운트를 이용한 보 구조물의 진동저감 해석)

  • 정우진;김두기;정의봉;홍성룡;최승복
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.499-504
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    • 2002
  • To reduce unwanted vibrations in war ship which may be transmitted through underwater path, it is required to use high damping mounts to isolate the vibration. In this work, the beam structure with squeeze mode ER mount is proposed and response characteristics such as acceleration and force transmissibility of beam with constant voltage and optimal controller are experimentally analyzed. The controller is empirically realized and control responses are evaluated in frequency domains. Experiments show vibration reduction capability of squeeze mode ER mount.

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An Experimental study on the Vibration absorber for vibration attenuation of cantilever beam structure (외팔보 구조물의 진동감쇠를 위한 동흡진기의 실험적 연구)

  • Kwag, Dong-Gi;Bae, Jae-Sung;Hwang, Jai-Hyuk;Kim, Hun-Soo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.627-632
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    • 2011
  • This study was carried out vibration attenuation of vibration absorber attached to the cantilever beam structure. Modern tank guns are stabilized to allow fire on the move while traversing uneven terrain. However, as the length of the barrel is extended, to meet required muzzle exit velocities, the terrain induced vibrations lead to increased muzzle pointing errors. Thus, reducing these vibrations should lead to increased accuracy. The vibration absorber includes a compliant energy storage device, such as a spring, and a mass secured to the energy storage device. In this study, it accomplished a research in about gun barrel vibration attenuation using tuned mass damper. The barrel was hung from a bungee cord for free - free condition. It accomplished a vibration experiment for verified attenuation efficiency.

  • PDF

The Application of welding numerical simulation on two typical welded structures in railway vehicles

  • Ya-na, Li;Cheng-tao, Li;Bin, Yuan;Su-ming, Xie
    • Interaction and multiscale mechanics
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    • v.5 no.2
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    • pp.145-155
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    • 2012
  • The thin-plate structure and the box-beam structure are two typical welded structures in railway vehicles. Because of their structure complexity, bigger size and multi-seams, welding residual distortion which occur in welding process bring unfavorable effect on the quality of welding products manufacturing and service. As a result, welding distortion forecasting and control become an important and urgent research topic in railway vehicles. In this paper, three different numerical methods are presented corresponding to three typical types of welded structures of railway vehicles and welding deformation are simulated. Consistence of numerical results and experimental data proves the correctness of models and feasibility of simulation methods.