• Steel and Composite Structures
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• v.21 no.2
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• pp.373-394
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• 2016

The postbuckling behavior of laminated composite plates and shells, subjected to various shear loadings, is presented, using a modified 8-ANS method. The finite element, based on a modified first-order shear deformation theory, is further improved by the combined use of assumed natural strain method. We analyze the influence of the shell element with the various location and number of enhanced membrane and shear interpolation. Using the assumed natural strain method with proper interpolation functions, the present shell element generates neither membrane nor shear locking behavior even when full integration is used in the formulation. The effects of various types of lay-ups, materials and number of layers on initial buckling and postbuckling response of the laminated composite plates and shells for various shear loading have been discussed. In addition, the effect of direction of shear load on the postbuckling behavior is studied. Numerical results and comparisons of the present results with those found in the literature for typical benchmark problems involving symmetric cross-ply laminated composites are found to be excellent and show the validity of the developed finite element model. The study is relevant to the simulation of barrels, pipes, wing surfaces, aircrafts, rockets and missile structures subjected to intense complex loading.

• Journal of Korean Society of Steel Construction
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• v.24 no.1
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• pp.73-80
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• 2012

The adoption of a composite beam system is regarded as a simple but effective solution because it improves the overall stiffness, strength and stability of the structure by welding shear studs. However, welding shear studs poses problems including electric shock and weld defects. Mechanical methods have emerged as an alternative to metallurgical methods for connecting the H-beam and shear connector. Four specimens were tested in order to compare the structural behavior of the proposed composite beams with that of the classical composite beam given the condition of horizontal loading. With the original composite beam (FCB-SB specimen) using stud bolts, hysteresis loops are stable, but its strength decreased with the crashing of the concrete slab around the column. The suggested composite beams using shear connectors also yielded stable hysteresis loops. Consequently, use of the suggested composite beams instead of the original composite beam are recommended.

• Magazine of the Korea Concrete Institute
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• v.23 no.4
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• pp.55-57
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• 2011

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.141-142
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• 2013

The modular construction method have improved quality, reduction of defects, such as the reduction of air, a number of advantages. It is utilized composite, larger, in skyscraper building already abroad. The domestic, various studies have been conducted on technical matters taller, automation of production, such as process control, but is still inadequate circumstances. Therefore, in this study, is the purpose that you have presented activation measures to investigate and analyze the case of co-housing with a modular construction system of outside, and to make the co-housing of modular construction system of domestic.

• Journal of the Korean Statistical Society
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• v.31 no.2
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• pp.153-161
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• 2002

A new method of construction of second order slope rotatable designs (SOSRD) using symmetrical unequal block arrangements (SUBA) with two unequal block sizes is suggested. The proposed method may sometimes lead to designs with less number of design points than those available in the literature. Further, bounds for the parameters of SOSRD are also obtained.

• Journal of the Korea Concrete Institute
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• v.22 no.5
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• pp.609-616
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• 2010

FRP-concrete composite deck, an innovative system, is composed of concrete in the top and FRP panel in the bottom. Bottom FRP panel can reduce self weight and improve workability. This system requires strong connection between FRP and concrete. Therefore coarse sand coating was previously applied on FRP to improve the bonding. In this study, concrete wedge method is newly introduced to enhance both vertical bond and fatigue performance. Three FRP-concrete composite deck specimens with the concrete wedges were manufactured, and static and fatigue tests were carried out. The results showed that the new FRP-concrete composite deck satisfied deflection and crack width limits set by the design codes. And the fatigue test showed that the composite deck was capable of two million load cycles under 50% of its static strength. Based on the results, it can be concluded that that this new system has outstanding mechanical and durability performance, and therefore, satisfactorily be used in designing FRP-concrete composite deck.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.707-716
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• 2011

It has been applied using cranes or insertion methods to install heavy structures to strengthen existing railway bridges. These methods are uneconomical because of two reasons. The first one is it is required to construct approach roads for heavy equipment and/or working yard. The second one is the electric lines shall be cutoff during construction. Both require additional construction cost and duration. In this study, new transport equipment was developed which can be applied to heavy structures up to 100 ton. Using this method, the heavy structure can be loaded into the new transport equipment at working yard and transported to the working site. This method can be applied, but not limited to railway bridge or roadbed rehabilitation. It was found that the precious construction can be achieved to install heavy structure using this method. The experimental construction to make non-ballast girder bridge composite with new pc deck slab using this method was carried out for Jewon bridge. The example bridge is in extreme condition because it locates above national road #38 within extreme transition curve and has 10 ‰ slope and skew. The experimental construction results were satisfactory both for safety and construction precision.

• Structural Engineering and Mechanics
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• v.64 no.3
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• pp.311-321
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• 2017

This paper presents the details of analytical studies carried out towards the prediction of flexural capacity and load-deflection behaviour of Laced Steel-Concrete Composite (LSCC) beams. Analytical expressions for flexural capacity of the beams are derived in accordance with the basic principles of conventional Reinforced Concrete (RC) beams, but incorporated with relevant modifications to account for the composite nature of the cross-section. The ultimate flexural capacity of the two LSCC beams predicted using the derived expressions is found to be approximately 20% lower than those obtained due to measurement from experiments. Further to these, two simple methods are also proposed on the basis of unit load method and equivalent steel beam method to determine the non-linear load-deflection response of the LSCC beams for monotonic loading. Upon validation of the proposed methods by comparing the predicted responses with those of experiments and finite element analysis, it is found that the methods are useful to find nonlinear response of such composite beams.

• Journal of Korean Society of Steel Construction
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• v.26 no.5
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• pp.473-483
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• 2014

According to the Korean Building Code (KBC), the validity of the application of 800MPa grade steel(HSA800) to composite column should be verified by experimental or analytical method. Thus, stub column tests for encased and filled composite members with HSA800 steel were conducted, and axial strength and the validity of design compressive strength equations in KBC were evaluated. The test results show that the equation of the compressive strength of encased composite column member in KBC should be modified in order to use HSA800 steel without any reduction of specified minimum yield strength. For this purpose, it is suggested that the interval of hoop should be narrowed and the effective concrete area should be used. The equation of the compressive strength of filled composite column member in KBC is applicable to filled composite column with HSA800 steel without any modification.

• Journal of Korean Society of Steel Construction
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• v.9 no.3 s.32
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• pp.333-340
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• 1997

This paper will expand the third-order shear deformation theory by the double-Fourier series and reduce to the solution of a system of ordinary differential equations in time, which are integrated numerically using Newmark's direct integration method and clarify the undamped dynamic responses for the cross-ply and antisymmetric angle-ply laminated composite plates and shells with simply supported boundary condition. Numerical results for deflections are presented showing the effect of side-to-thickness ratio, aspect ratio, material anisotropy, and lamination scheme.