• Structural Engineering and Mechanics
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• 제68권5호
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• pp.591-601
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• 2018

Non-moment beam-to-column connections, which are usually referred to as simple or shear connections, are typically designed to carry only gravity loads in the form of vertical shears. Although in the analysis of structures these connections are usually assumed to be pinned, they may provide a small amount of rotational stiffness due to the typical connection details. This paper investigates the effects of this small rotational restraint of simple beam-to-column connections on the behavior and seismic response of steel braced non-moment resisting frames. Two types of commonly used simple connections with bolted angles, i.e., the Double Web angle Connection (DWC) and Unstiffened Seat angle Connection (USC) are considered for this purpose. In addition to the pinned condition - as a simplified representation of these connections - more accurate semi-rigid models are established and then applied to some frame models subjected to nonlinear pushover and nonlinear time history analyses. Although the use of bracing elements generally reduces the sensitivity of the global structural response to the behavior of connections, the obtained results indicate considerable effects on the local responses. Namely, our results show that consideration of the real behavior of connections is essential in designing the column elements where the pin-connection assumption significantly underestimates design of outer columns of upper stories.

• Steel and Composite Structures
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• 제4권5호
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• pp.403-418
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• 2004

Lateral sway is most likely to control the design of semi-rigid steel frames where the frame arrangements do not include any form of bracing. This paper investigates the sway behaviour of semi-rigid regular steel frames i.e., frames having the same arrangement of beam and column sections at all levels, and hence proposes some design charts for the prediction of sway that eliminate the need for doing any numerical modelling. Schueller's equation has also been modified to incorporate connection flexibility in addition to its original rigid frame considerations. All the proposed methods have been validated using results obtained from numerical analysis.

• 대한수학회보
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• 제50권3호
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• pp.705-717
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• 2013

In this paper, we study the geometry of half lightlike submanifolds M of a semi-Riemannian manifold $\tilde{M}$ with a semi-symmetric non-metric connection subject to the conditions; (1) the characteristic vector field of $\tilde{M}$ is tangent to M, the screen distribution on M is totally umbilical in M and the co-screen distribution on M is conformal Killing, or (2) the screen distribution is integrable and the local lightlike second fundamental form of M is parallel.

• Journal of Korean Society for Atmospheric Environment
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• 제23권E1호
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• pp.29-38
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• 2007

A cylindrical tube connection that has a voltage difference and is separated electrically by an insulator was modelled. The penetration efficiencies of charged particles passing through the connector tube were investigated. Typically, as the particle size decreases and the applied voltage difference increases, the penetration efficiency decreases. To assess the effect of the electrode geometry, various lengths of electric insulator and aerosol flow rate with a fixed tube length and tube diameter were used when calculating penetration efficiencies. The comparison of penetration efficiencies for various electrode geometry setups suggests that the penetration efficiency can be described as a function of the product of applied voltage and electrical mobility of charged particles. The diffusion loss from this and previous studies are compared. Further, an explicit form for penetration efficiency is provided as a function of a new non-dimensional parameter, $Es(=Z_pV/U_{avg}W);\;P_{es}=0.2{\cdot}{\exp}(-Es/0.6342)+0.8{\cdot}{\exp}(-Es/4.7914)$.

• 대한수학회지
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• 제36권5호
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• pp.959-1008
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• 1999

This paper considers foundational issues related to connections in the tangent bundle of a manifold. The approach makes use of second order tangent vectors, i.e., vectors tangent to the tangent bundle. The resulting second order tangent bundle has certain properties, above and beyond those of a typical tangent bundle. In particular, it has a natural secondary vector bundle structure and a canonical involution that interchanges the two structures. The involution provides a nice way to understand the torsion of a connection. The latter parts of the paper deal with the Levi-Civita connection of a Riemannian manifold. The idea is to get at the connection by first finding its.spary. This is a second order vector field that encodes the second order differential equation for geodesics. The paper also develops some machinery involving lifts of vector fields form a manifold to its tangent bundle and uses a variational approach to produce the Riemannian spray.

• 한국산업융합학회 논문집
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• 제9권3호
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• pp.215-220
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• 2006

Recently, steel-concrete composite slab decks have been widely used as highway bridge decks. In the construction of the composite slab decks, it is necessary to join two adjacent blocked bottom plates to form one unite in the longitudinal direction. In this paper, several types of longitudinal direction joints for Robinson type composite slab decks ared proposed herein and static bending test are carried out by using slab specimens. And the stress and deformation of the tensile grip connection with high strength bolts are discussed by using three-dimensional elastic-plastic FEM.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.988-993
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• 2004

This paper considers corrosion problems in the bolt connection of weathering steel box girder bridge using the external electric type corrosion resistance method which resisted to local corrosion in coated steel surface with contacted air. The weathering steel was created a rust itself in the passive state. but a coated box girder type was easily dew form could be made galvanic cell that accelerated corrosion. so that it was ruled by protection coat with some paint. Therefore, it needed that can be applied the external electric type corrosion resistance method in coated surface. As a result of the test of polarization amount had measured that the weathering steel was higher currents than the general steel by about $5\~10\%$. Therefore. an external electric type corrosion resistance method can be used to protect local corrosion in the coated bolt connection of weathering steel box girders effectively.

• Structural Engineering and Mechanics
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• 제35권5호
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• pp.617-630
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• 2010

Different types of moment resisting connections are commonly used to transfer the induced seismic moments between frame elements in an earthquake resisting structure. The local connection behavior may drastically affect the global seismic response of the structure. In this study, the finite element and experimental seismic investigations are implemented on two frequently used connection type to evaluate the local behavior and to reveal the failure modes. An alternative connection type is then proposed to eliminate the unfavorable brittle fracture modes resulted from probable poor welding quality. This will develop a reliable predefined ductile plastic mechanism forming away from the critical locations. Employing this technique, the structural reliability of the moment resisting connections shall be improved by achieving a controllable energy dissipation source in form of yielding of the cover plates.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1990년도 가을 학술발표회 논문집
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• pp.73-78
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• 1990

Large panel building systems are composed of vertical wall panels which support horizontal roof and floor panels to form a box like structure. The simplecity of the connections, which makes precast concrete economically viable, causes a lack of continuity in stiffness, strength and ductility. This precast concrete large panel systems typically have weak connection regions. Three types of 2-story full-scale precast concrete subassemblages were tested under reversed cyclic loading. The seismic resistance capacity and failure mode of each system are compared in connection with the characteristics of joint connection details.

• 한국공간구조학회논문집
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• 제23권2호
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• pp.45-52
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• 2023

Modular construction is an economical and efficient construction that reduces time and costs by manufacturing units in factories and constructing them on site. Currently, the demand for modular construction is increasing not only abroad but also domestically. As the demand for modular construction increases, a lot of development and research on connections between modular units are being conducted. Connections between modular units should be quick and simple to assemble when assembling units on site, and should be in a form that allows each unit to be connected regardless of direction. In addition, it must be able to exert sufficient strength against external loads. In this study, a connection between modular units using connecting steel plates and bolts was proposed, and the nonlinear behavior of the connection to external lateral force was analyzed through finite element analysis, and resistance performance was evaluated.