• 한국건설관리학회논문집
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• 제2권4호
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• pp.144-156
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• 2001

본 연구에서는 종래 건설 프로세스 상의 한계점을 분석한 후, 그 개선방안을 제시하였다. 본 연구에서 제시하는 개선방안은 설계도서의 철저한 사전검토를 통한 협력 업체의 공정계획 조기참여 방안이다. 이를 통해서 커뮤니케이션이 활성화되어 사전의견조정의 극대화를 확보할 수 있다. 본 연구에서는 데크플레이트 설치 프로세스와 덕트 설치 프로세스를 대상으로 사례연구를 수행하였다. 사례연구 결과, 협력업체의 조기투입과 설계도서 사전 검토를 통하여 체계적으로 건설 프로세스를 개선할 수 있었고, 구성원들의 사전의견조정을 통하여 건설생산 효율성을 제고할 수 있었다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2009년도 춘계학술대회 논문집
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• pp.326-331
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• 2009

An algorithm is proposed for computing dynamic displacements of a bridge using FBG sensors. An existing algorithm for estimating dynamic displacements of a simply supported beam through mode superposition is extended and applied to various types of bridges with bending and torsional modes. The proposed algorithm is examined through field tests on a suspension span steel deck plate box girder bridge. Guidelines are provided for determining the number of modes and the number of strain gages to be used.

• Wind and Structures
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• 제18권3호
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• pp.215-233
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• 2014

This paper presents a method to extract flutter derivatives of bridge decks based on a combination of the computational fluid dynamics (CFD), system simulations and system identifications. The incompressible solver adopts an Arbitrary Lagrangian-Eulerian (ALE) formulation with the finite volume discretization in space. The imposed sectional motion in heaving or pitching relies on exponential time series as input, with aerodynamic forces time histories acting on the section evaluated as output. System identifications are carried out to fit coefficients of the inputs and outputs of ARMA models, as to establish discrete-time aerodynamic models. System simulations of the established models are then performed as to obtain the lift and moment exerting on the sections to a sinusoidal displacement. It follows that flutter derivatives are identified. The present approaches are applied to a hexagon thin plate and a real bridge deck. The results are compared to the Theodorsen closed-form solution and those from wind tunnel tests. Satisfactory agreements are observed.

• 산업기술연구
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• 제16권
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• pp.123-129
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• 1996

A method of calculating the natural frequency corresponding to the first mode of vibration of beams and tower structures with irregular cross-sections and with arbitrary boundary conditions was developed and reported by D. H. Kim in 1974. In order to obtain the natural frequency by the presented method, the first step to take is to obtain the deflection influence surfaces. In design and analysis of any structure, the first step to be taken is to obtain this deflection influence surfaces. Any method can be used for this purpose. Then using this surfaces, deflections, slopes, moments, shears, and natural frequencies can be obtained by differentiating either the continuous function or discrete function defined at certain points. The merit of the presented method is that the natural frequency can be obtained by the deflection influence surfaces obtaining which is the first step in structural analysis.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.300-303
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• 2004

In this paper, floor impact noise reduction in a cruise ship cabin by using floating floor is studied. A mock-up is built by using 61 steel plate, and two identical cabins are made where 25t panel is used to construct wall and ceiling inside the steel structure. Various floating floor systems are tested for which normalized impact noise is measured according to ISO 140-7 It is shown that effect of VL(Visco-elastic Layer) is negligible when it is used between deck and mineral wool, since most vibration absorption occurs in the wool. In addition, direction of the mineral wool fiber affects impact noise significantly.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1995년도 추계학술대회논문집; 한국종합전시장, 24 Nov. 1995
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• pp.172-178
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• 1995

보강평판은 평판에 각종 보강재를 용접등의 방법에 의해서 종방향, 횡방향, 경사 또는 임의의 방향으로 부착시켜 굽힘 및 비틀림 강성을 향상시킨 구조요소이다. 이러한 구조요소는 구조적 필요성이나 경량화 설계에 따라 선박의 deck, 철도 차량, 항공기 및 자동차 등의 각종 구조물에서 부하능력 및 경제성을 증대시키기 위하여 널리 사용되고 있고, 또한 자동차용 오일팬, 가전기기의 케이싱과 모터의 케이싱등에도 사용되고 있다. 최근 현장에서는 이러한 구조물의 진동 감소 및 방진 문제가 큰 관심사가 되고 있다. 본 논문은 정사각형 알루미늄 평판에 +자 형태의 Box Beam 보강재를 편면 보강하고 4변 자유단의 경계 조건을 설정하였다. 보강재는 유한요소 정식화 과정을 통하여 평판 요소에 등가시키고, 2차원의 평판 구조로 보강 평판을 모델링하고 구조해석 프로그램인 ANSYS를 이용하여 해석하였다. 실험은 Impact Test에 의해서 주파수 응답 함수(FRF)를 각 시편에 대해서 구하고 이를 해석의 고유진동수와 비교하였다. 그리고 보강재가 임의의 각도로 평판에 부착되었을 때 고유진동수의 변화와 진동 모드(mode shape)를 분석하였다.

• 한국소음진동공학회논문집
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• 제24권12호
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• pp.948-953
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• 2014

Many studies using the assumed mode method have been found for the free vibration analysis of stiffened plate with known elastic boundary conditions. However many local structures such as tank edges and equipment foundations consist of connected structures and it is very difficult to find suitable elastic boundary conditions. In this study combined polynomials which satisfy simply and fixedly supported boundary conditions are proposed. The proposed method has been applied to tanks which bounded by bulkhead and a deck. The results of this study shows good agreements with these obtain by the FEA S/W(Patran/Nastran).

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1999년도 가을 학술발표회 논문집
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• pp.135-142
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• 1999

Plate girder bridges for tile Korean high-speed railway are optimally designed. Static and dynamic constraints are all considered. The design variables are the thicknesses and the lengths of the plates that are used to form I-shaped main girders with variable cross-sections. And the objective function is tile steel weight of a main girder. A C++ based design program is developed; this program interfaces with a FORTRAN based optimization program ADS. From the results of optimal design for various span lengths, it is observed that the deck vertical acceleration is one of the most important constraints in a special range of tile span length. Front a parametric study, sensitivity of the optimal design to static as well as dynamic constraints are presented.

• 대한조선학회지
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• 제8권2호
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• pp.1-12
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• 1971

This paper describes, firstly, on analytical method of computing the eigenvalues of vertical vibration of ships, taking into account for the distribution of hull weight including added mass and the effect of shear deflection and rotary inertia. The frequency equation is solved by Galerkins method into form of numerical integration. Applying the above described equation, model experiment of vertical vibration was carried out in order to varify the validity of the analytical method of vertical vibration. The model, which was made of acrylite plate, was ship-shaped wall-sided vessel with bulkheads, deck openings, and fore and after peak tank at both ends. The results of experiments carried out both in air and on water showed that the observed natural frequencies and the observed patterns of natural modes of vibration were in good agreement with analytically calculated values for 2,3, and 4-node vibration.

• 산업기술연구
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• 제18권
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• pp.107-115
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• 1998

Many of the bridge and building floor systems, including the girders and cross-beams, also behave a similar special orthotropic plates. Such plates are subject to the concentrate masses in the form of traffic loads, or the test equipments such as the accelerator in addition to their own masses. Analysis of such problems is usually very difficult. Most of the bridge slabs on girders have large aspect ratios. Finite difference method is used for this purpose, in this paper. The result is compared with that of the beam theory.