• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2008년도 정기 학술대회
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• pp.65-70
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• 2008

The capacity spectrum method (CSM) is a deterministic seismic analysis approach wherein the expected seismic response of a structure is established as the intersection of the demand and capacity curves. Recently, there are a few studies about a probabilistic CSM where uncertainties in design factors such as material properties, loads, and ground motion are being considered. However, researches show that soil-structure interaction also affects the seismic responses of structures. Thus, their uncertainties should also be taken into account. Therefore, this paper presents a probabilistic approach of using the CSM for seismic analysis considering uncertainties in soil properties. For application, a reinforced concrete bridge column structure is employed as a test model. Considering the randomness of the various design parameters, the structure's probability of failure is obtained. Monte Carlo importance sampling is used as the tool to assess the structure's reliability when subjected to earthquakes. In this study, probabilistic CSM with and without consideration of soil uncertainties are compared and analyzed. Results show that the analysis considering soil structure interaction yields to a greater probability of failure, and thus can lead to a more conservative structural design.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2007년도 정기총회 및 학술발표대회
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• pp.307-311
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• 2007

In the case of the railway bridges, uplift forces were occurred at the edge of the segments when vehicular loads were applied. These forces made the compressive and tensile forces occur in the fastening system. Therefore, the structural analysis was performed to investigate the safety of fastening system which was modeled as one directional spring element. In this case, the stiffness of the spring element was obtained from experimental study which was conducted by compressive load. For that reason, to perform rational and exact structural analysis, the translational stiffness of the fastening system obtained from the experimental study applied the tensile load and the rotational stiffness should be considered because it was occurred the tensile force as well as the compressive force in fastening system. In this study, an elastic and inelastic experimental study was performed for six specimens. The translational stiffness along the vertical axis of rail and the rotational stiffness along the strong axis of rail were investigated. Also structural behavior of the fastening system was analyzed.

• 콘크리트학회논문집
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• 제14권5호
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• pp.653-659
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• 2002

최근들어, 국내에서 공용중인 교량바닥판의 파손사례가 증가되고 있으며, 파손된 바닥판의 주요 파괴모드는 반복되는 중트럭 하중에 의한 국부적인 펀칭전단이 주원인이 되고 있다. 본 연구에서는 교축방향으로 프리스트레스가 도입된 프리캐스트 콘크리트 교량바닥판에 대해서 펀칭전단 파괴실험을 수행하여 펀칭전단 실험중에 얻어진 균열양상, 파괴모드, 처짐 및 응력 특성, 펀칭전단강도 등을 검토하였다. 정적 펀칭전단 실험결과 교량바닥판의 펀칭전단 파괴는 현행 시방서의 예측식에값 보다 더 큰 하중 수줄에서 발생되어 현행 시방서에서 규정하는 펀칭전단 강도는 안전측의 결과를 보이는 것으로 판단된다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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• pp.125-130
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• 2001

A existing design method of PSC girder bridges, according to total service loads, stress required tendon force at a time. Because this design method increases beam depth, design of long span is difficult. However, As UC girder stressing at difficult loading stages reduces sectional depth of PSC girder, both design and operation of long span bridges is possible. so, this study analyzes the effect of design parameter (Girder Strength, Girder Spacing, Span Length, Joint Strength) on the beam depth of IPC girder continuous bridges, and shows sectional depth of UC girder for design of long span bridges. According to analysis, when a continuous bridges of same length span is at strength of joint over strength of girder of 600kg/$cm^{2}$, a change of beam depth is observed and when a continuous bridges of different span length is at strength of joint below strength of girder of 600kg/$cm^{2}$, a change of beam depth is observed. In two case, a change of beam depth is mostly observed over strength of girder of 350kg/$cm^{2}$ according to analysis of deflection data, a continuous bridges of IPC girder is nearly satisfied.

• 복합신소재구조학회 논문집
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• 제1권1호
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• pp.9-15
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• 2010

In this paper, A reinforced concrete slab bridges is analyzed by the composite laminates theory. Both the geometry and the material of the cross section of the reinforced concrete slab bridge are considered symmetrical with respect to the mid-surface so that the bending extension coupling stiffness, Bij = 0, and D16 = D26 = 0. Each longitudinal and transverse steel layer is regarded as a lamina, and material constants of each lamina is calculated by the use of rule of mixture. This slab with simple support is under uniformly distributed vertical and axial loads. In this paper, the finite difference method and specially orthotropic laminates theory are used for analysis. The result of specially orthotropic laminates theory analysis is modified to obtain the solution of the beam analysis. The result of this paper can be used for reinforced concrete slab analysis by the engineers with undergraduate study in near future.

• Smart Structures and Systems
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• 제6권2호
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• pp.167-182
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• 2010

An adaptronic strut for machine tools with parallel kinematics for compensation of the influence of geometric errors is introduced. Implemented within the strut is a piezoelectric sensor-actuator unit separated in function. In the first part of this contribution, the functional principle of the strut is presented. For use of one piezoelectric transducer as both, sensor and actuator as so-called self-sensing actuator, the acquisition of the sensing signal while actuating simultaneously using electrical bridge circuits as well as filter properties are examined. In the second part the control concept developed for the adaptronic strut is presented. A co-simulation model of the strut for simulating the controlled multi-body behavior of the strut is set-up. The control design for the strut as a stand-alone system is tested under various external loads. Finally, the strut is implemented into a model of the complete machine tool and the influence of the controlled strut onto the behavior of the machine tool is examined.

• Steel and Composite Structures
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• 제11권5호
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• pp.375-390
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• 2011

Composite beam, which combined the material characteristic of the steel and concrete, has been widely used in the construction of various building and bridge system. For the effective application of the composite beam, the composite action on the composite interface between the concrete element and the steel element should be achieved by shear connectors. The behavioral characteristics of composite beam are related with the degree of interaction and the degree of shear connection according to the shear strength and shear stiffness of the stud shear connectors. These two concepts are also affected by the number of installed shear connector and the strength of composite materials. In this study, experimental and analytical evaluations of the degree of shear connection affected by stud diameter were conducted, and the relationship between structural behavior and the degree of shear connection was verified. The very small difference among the ultimate loads of the specimens depending on the change of the degree of connection was possibly because of the dependence of the ultimate load on the characteristic of plastic moment of the composite beam.

• Computers and Concrete
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• 제10권5호
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• pp.435-455
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• 2012

In the recent years, rehabilitation of structures, strengthening and increasing the ductility of them under seismic loads have become so vital that many studies has been carried out on the retrofit of steel and concrete members so far. Bridge piers are very important members concerning rehabilitation, in which the plastic hinging zone is very vulnerable. Pier is usually confined by special stirrups predicted in the design procedure; moreover, fiber-reinforced polymers (FRP) jackets are used after construction to confine the pier. FRP wrapping of the piers is one of the most effective ways of increasing moment and ductility capacity of them, which has a growing application due to its relative advantages. In many earthquake-resistant bridges, reinforced concrete columns have a major defect which could be retrofitted in different ways like using FRP. After rehabilitation, it is important to check the strengthening adequacy by dynamic nonlinear analysis and precise modeling of material properties. If the plastic hinge properties are simplified for the strengthened members, as the simplified properties which FEMA 356 proposes for non-strengthened members, static nonlinear analysis could be performed more easily. Current paper involves this matter and it is intended to determine the plastic hinge properties for static nonlinear analysis of the FRP-strengthened circular columns.

• Structural Engineering and Mechanics
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• 제19권1호
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• pp.1-20
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• 2005

The expertise required in the judicious use of nonlinear finite element (FE) packages for design-assistance purposes is not widely available to the average engineer, whose sole aim may be to obtain an estimate for a single design parameter, such as the limit load capacity of a structure. Such a parameter may be required for the design of a proposed reinforced concrete (RC) floor slab or bridge deck with a given set of geometrical and material details. This paper outlines a procedure for developing design-assistance equations for carrying out such predictions for partially restrained RC slabs under uniformly distributed loading condition, based on a database of FE results previously generated from a large number of 'numerical model' slabs. The developed equations have been used for predicting the peak loads of a number of experimental RC slabs having varying degrees of edge restraints; with results showing a reasonable degree of accuracy and low level of scatter. The simplicity of the equations makes them attractive and their successful use in the field of application reported in this paper suggest that the outlined procedure may also be extended to other classes of concrete structures.

• 한국태양에너지학회 논문집
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• 제24권2호
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• pp.33-38
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• 2004

Outside wall systems we lost much energy from the dew of thermal bridge and unsuitable adiabatic construction. The air vent wall system can make reduce cooling loads from the outside wall in summer. The basic concept is connected with buoyant force by the difference of density. An external surface of a wall absorbs solar radiation, and transfers it to the air in the cavity. The warmed air gets buoyant force. So the warmed air is released through the top opening and cooler outside air replaces the space in the cavity. So because of the cavity and the openings, the cooling load reduction by natural ventilation is believed to be considerable. The purpose of this study is finding optimal length of air cavity by numerical analyses.