• Title, Summary, Keyword: Beam structure

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A study on the Framed Structure with Triple Beam In the Korean Wooden Architecture (한국 목조건축의 삼중량(三重樑) 가구(架構)에 관한 연구)

  • Yang, Jae-Young
    • Journal of architectural history
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    • v.17 no.3
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    • pp.61-80
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    • 2008
  • The purpose of this study is to discover the characteristics and the change of the framed structure with triple beam. 61 existing buildings with the triple beam structure were selected and analyzed extensively. The result of this study could be described in detail like below. The triple beam structure is used in the highly graded and symbolized building like the Buddhist sanctum and the Confucian sanctum. And the triple beam structure was chiefly used in $1600{\sim}1800's$. Generally, 1 Koju-type with Toikan(退間) is applied to the triple beam structure. Despite of the sameness of framed structure, there is a tendency that the rear Toikan(後退間) is used in the Buddhist sanctum and the front Toikan(前退間) is used in the Confucian sanctum. This different application of the Toikan(退間) resulted from the different spatial characteristics which reflect function and grade of the building. The application of Sangjungdori(上中道里, upper purlin) and two Danyeon(短椽, short rafter) is a necessary consequence, because Jungbo(중보, middle beam) is located between Daebo(대보, beam) and Jongbo(종보, small and high located beam) as an additional member of frame. And these are essential characteristics of the framed structure with triple beam. The triple beam structure is formed in a transitional period, as the result from eliminating the inner high-column from the 2 Koju and double beam structure. Though the Daebo is longer, the structure is more stable. But the rate of application of the triple beam structure is low, because it does not exceed the double beam structure in merits. Some of buildings with the triple beam structure has the asymmetrical characteristic in design, which is appeared in the latter period of Joseon Dynasty.

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The modal characteristics of non-uniform multi-span continuous beam bridges

  • Shi, Lu-Ning;Yan, Wei-Ming;He, Hao-Xiang
    • Structural Engineering and Mechanics
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    • v.52 no.5
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    • pp.997-1017
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    • 2014
  • According to the structure characteristics of the non-uniform beam bridge, a practical model for calculating the vibration equation of the non-uniform beam bridge is given and the application scope of the model includes not only the beam bridge structure but also the non-uniform beam with added masses and elastic supports. Based on the Bernoulli-Euler beam theory, extending the application of the modal perturbation method and establishment of a semi-analytical method for solving the vibration equation of the non-uniform beam with added masses and elastic supports based is able to be made. In the modal subspace of the uniform beam with the elastic supports, the variable coefficient differential equation that describes the dynamic behavior of the non-uniform beam is converted to nonlinear algebraic equations. Extending the application of the modal perturbation method is suitable for solving the vibration equation of the simply supported and continuous non-uniform beam with its arbitrary added masses and elastic supports. The examples, that are analyzed, demonstrate the high precision and fast convergence speed of the method. Further study of the timesaving method for the dynamic characteristics of symmetrical beam and the symmetry of mode shape should be developed. Eventually, the effects of elastic supports and added masses on dynamic characteristics of the three-span non-uniform beam bridge are reported.

Evaluation of Effective Stiffness for 3D Beam with Repeated Structure

  • Chung, Il-Sup
    • International Journal of Precision Engineering and Manufacturing
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    • v.7 no.2
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    • pp.25-29
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    • 2006
  • Analysis of structures which are composed of numerous repeated unit structures can be simplified by using homogenized properties. If the unit structure is repeated in one direction, the whole structure may be regarded as a beam. Once the effective stiffness is obtained from the analysis of the unit structure in a proper way, the effort for the detail modeling of the global structure is not required, and the real structure can be replaced simply with a beam. This study proposes a kinematical periodicity constraint to be imposed on the FE model of the unit structure, which improves the accuracy of the effective stiffness. The method is employed to a one dimensionally arrayed 3D structure containing periodically repeated unsymmetrical holes. It is demonstrated that the deformation behavior of the homogenized beam agrees well with that of the real structure.

Evaluation of Effective Stiffness for 3D Beam with Repeated Structure (반복 구조로 구성된 3차원 보의 유효 강성 계산)

  • Chung Ilsup
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.7
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    • pp.170-176
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    • 2005
  • Analysis of structures which are composed of numerous repeated unit structures can be simplified by using homogenized properties. If the unit structure is repeated in one direction, the whole structure may be regarded as a beam. Once the effective stiffness is obtained from the analysis of the unit structure in a proper way, the effort for the detail modeling of the global structure is not required, and the real structure can be replaced simply with a beam. This study proposes a kinematical periodicity constraint to be imposed on the FE model of the unit structure, which improves the accuracy of the effective stiffness. The method is employed to a one dimensionally arrayed 3D structure containing periodically repeated un-symmetric holes. It is demonstrated that the deformation behavior of the homogenized beam agrees well with that of the real structure.

Dynamic Analysis of a Moving Vehicle on Flexible Beam structures ( I ) : General Approach

  • 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.54-63
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    • 2002
  • In recent years, mechanical systems such as high speed vehicles and railway trains moving on elastic beam structures have become a very important issue to consider. In this paper, a general approach, which can predict the dynamic behavior of a constrained mechanical system moving on a flexible beam structure, is proposed. Various supporting conditions for the foundation support are considered for the elastic beam structure. The elastic structure is assumed to be a non-uniform and linear Bernoulli-Euler beam with a proportional damping effect. Combined differential-algebraic equation of motion is derived using the multi-body dynamics theory and the finite element method. The proposed equations of motion can be solved numerically using the generalized coordinate partitioning method and predictor-corrector algorithm, which is an implicit multi-step integration method.

Fabrication of Laser Diodes using Beam-Lead and its thermal characteristics (Beam-Lead를 이용한 Laser Diode의 제작과 열저항 특성)

  • 조성대
    • Proceedings of the Optical Society of Korea Conference
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    • pp.69-72
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    • 1990
  • For the effective heat transfering in Lser Diodes, Beam-Lead structure were introduced which is applicable to hybrid Optoelectronic Integrated Circuits. A 5-layer planar structure Laser Diode is fabricated and Beam-Lead is made by Au plating. And carrier was made by etching Si substrate and LD was mounted on a carrier. The thermal resistance was measured and we could certain that Beam-Lead structure behaves well as a heat sink.

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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.

Residual Stress Measurement of Micro Gold Electroplated Structure

  • Baek, Chang-Wook;Kim, Yong-Kweon;Cho, Chul-Ho;Yoomin Ahn
    • International Journal of Precision Engineering and Manufacturing
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    • v.3 no.2
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    • pp.72-77
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    • 2002
  • In this paper, a simple method to measure the residual stress in microstructure is presented. In order to find the residual stress in micro-machined beam, the first natural frequency of the beam that has the residual stress inside is analyzed using Rayleigh's energy method. Micro gold electroplated structure is fabricated by surface micro-machining process including electroplating. The made structure is an approximate shape of clamped-clamped beam and its 1 st natural frequency is measured by resonance method. For the better estimation of the residual stress, an equivalent length of micro-fabricated beam to ideal beam is calculated by FEM. The residual stress was estimated from the equivalent length and the measured natural frequency. It was found that a tensile stress was residue in the micro beam structure.

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.

The plan of rational span decision to track beam of monorail (모노레일 시스템 궤도빔의 합리적인 경간장 결정방안)

  • Ahn, Yong-Mo;Baek, Cha-Seung
    • Proceedings of the KSR Conference
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    • pp.199-205
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    • 2008
  • The monorail system as new transportation system mostly has being constructed as an elevated construction and the track beam as mostly main work type occupy the important parts. The structure of monorail system, the track beam support directly vehicle's load and comprised of the track beam structure to be traveling side and understructure to be transmitted from their load to the ground. In particular, in case of construction to elevated structure in the center of a city, it is important to decision plan for span to be considered the economic, execution and maintenance according to transport, installation, and the structure problem, scene and civil appeals to be decided the beam elevation and span. Therefore the standard span of monorail track beam shall be considered the efficient execution, economic and transportation. And propose to reasonable decision plan incorporated the minimizing the road occupied width due to openness to center of a city and bridge pole, minimize to basis size.

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