• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.12
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• pp.5177-5183
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• 2010

The effects of the ovalization of the tangential pipes to the elbows are analyzed. The geometric nonlinear behaviors of the elbows are shown with the element capable of ovalization. The relationships between the length of the tangential pipes in the models and the bend angles of the elbows are analyzed to supplement the ASME code. And the proper length of the tangential pipes for the elbow models are suggested.

• International Journal of Concrete Structures and Materials
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• v.10 no.2
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• pp.125-142
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• 2016

An overall review of the structural behaviors of ultra-high-performance fiber-reinforced concrete (UHPFRC) elements subjected to various loading conditions needs to be conducted to prevent duplicate research and to promote its practical applications. Thus, in this study, the behavior of various UHPFRC structures under different loading conditions, such as flexure, shear, torsion, and high-rate loads (impacts and blasts), were synthetically reviewed. In addition, the bond performance between UHPFRC and reinforcements, which is fundamental information for the structural performance of reinforced concrete structures, was investigated. The most widely used international recommendations for structural design with UHPFRC throughout the world (AFGC-SETRA and JSCE) were specifically introduced in terms of material models and flexural and shear design. Lastly, examples of practical applications of UHPFRC for both architectural and civil structures were examined.

• Structural Engineering and Mechanics
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• v.56 no.4
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• pp.605-623
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• 2015

A formulation of the boundary element method (BEM) based on Kirchhoff's hypothesis to analyse stiffened plates composed by beams and slabs with different materials is proposed. The stiffened plate is modelled by a zoned plate, where different values of thickness, Poisson ration and Young's modulus can be defined for each sub-region. The proposed integral representations can be used to analyze the coupled stretching-bending problem, where the membrane effects are taken into account, or to analyze the bending and stretching problems separately. To solve the domain integrals of the integral representation of in-plane displacements, the beams and slabs domains are discretized into cells where the displacements have to be approximated. As the beams cells nodes are adopted coincident to the elements nodes, new independent values arise only in the slabs domain. Some numerical examples are presented and compared to a wellknown finite element code to show the accuracy of the proposed model.

• Structural Engineering and Mechanics
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• v.40 no.4
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• pp.489-500
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• 2011

The elastic seismic response of plan-asymmetric multi storey steel-frame buildings is investigated under earthquake loading with particular emphasis on forward-rupture directivity and fling records. Three asymmetric building systems are generated with different torsional stiffness and varying static eccentricity. The structural characteristic of these systems are designed according to UBC 97 code and their seismic responses subjected to a set of earthquake records are obtained from the response history analysis (RHA) as well as the linear static analysis (LSA). It is shown that, the elastic torsional response is influenced by the intensity of near-fault ground motions with different energy contents. In the extreme case of very strong earthquakes, the behaviour of torsionally stiff buildings and torsionally flexible buildings may differ substantially due to the fact that the displacement envelope of the deck depends on ground motion characteristics.

• Structural Engineering and Mechanics
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• v.28 no.2
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• pp.189-206
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• 2008

In several design codes and specifications, simplified formulae and charts are given for determining the effective lengths of frame columns. It is shown that these formulae may yield rather erroneous results in certain cases. This is due to the fact that, the code formulae utilise only local stiffness distributions. In this paper, a simplified procedure for determining approximate values for the buckling loads of braced frames is developed. The procedure utilises a fictitious load analysis of frames and yields errors less than 10%, which may be considered suitable for design purposes. The proposed procedure is applied to several numerical examples and it is shown that all the errors are in the acceptable range.

• Wind and Structures
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• v.4 no.1
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• pp.45-62
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• 2001

This paper is focused on the torsional effects that are induced on bridge piers by unbalanced wind buffeting on the deck during double cantilever erection stages. The case of decks with variable cross section is considered in particular as this characteristic is typical of most frame bridges that are built by the cantilever method. The procedure outlined in the paper is basically an application of the method that Dyrbye and Hansen (1996) have illustrated for decks with constant cross section. This format was chosen because it is suitable for design purposes and may easily be implemented in structural codes. As a complement, the correspondence with the format that is adopted in the Canadian code (NBCC 1990) for the gust factor is established, which might be useful to bridge designers used to the North-American approach to the gust effects on structures. Only alongwind turbulence and horizontal movements of the deck are considered. The combination of torsional and bending effects is also discussed and it is illustrated with an example of application.

• Structural Engineering and Mechanics
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• v.19 no.1
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• pp.55-71
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• 2005

In several design codes and specifications, simplified formulae and diagrams are given for determining the buckling lengths of frame columns. It is shown that these formulae may yield rather erroneous results in certain cases. This is due to the fact that, the code formulae utilise only local stiffness distributions. In this paper, a simplified procedure for determining approximate values for the buckling loads of multi-storey frames is developed. The procedure utilises lateral load analysis of frames and yields errors in the order of 10%, which may be considered suitable for design purposes. The proposed procedure is applied to several numerical examples and it is shown that all the errors are in the acceptable range and on the safe side.

• Structural Engineering and Mechanics
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• v.19 no.1
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• pp.21-42
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• 2005

A method is presented to detect and assess the structural damage from changes in natural frequencies using Genetic Algorithm (GA). Using the natural frequencies of the structure, it is possible to formulate the inverse problem in optimization terms and then to utilize a solution procedure employing GA to assess the damages. The technique has been applied to a cantilever beam and a plane frame, each one with different damage scenario to study the efficiency of the developed algorithm. A laboratory tested data has been used to verify the proposed algorithm. The study indicates the potentiality of the developed code to solve a wide range of inverse identification problems in a systematic way. The outcomes show that this method can detect and estimate the amount of damages with satisfactory precision.

• Structural Engineering and Mechanics
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• v.52 no.1
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• pp.137-147
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• 2014

The present paper deals with the first ply failure analysis of the laminated composite plates under various static and dynamic loading conditions. Static analysis has been carried out under patch load and triangular load. The dynamic failure analysis has been carried out under triangular pulse load. The formulation has been carried out using the finite element method and a computer code has been developed. The first order shear deformation theory has been applied in the present formulation. The displacement time history analysis of laminated composite plate has been carried out and the results are compared with those published in literature to validate the formulation. The first ply failure load for laminated composite plates with various lamination schemes under static and dynamic loading conditions has been calculated using various failure criteria. The failure index-time history analysis has also been carried out and presented in this paper.

• Journal of the Korean Institute of Navigation
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• v.17 no.2
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• pp.107-119
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• 1993

When the breach of contract is at issue between the contracting parties, the decision of the contents of obligation has an important meaning. The contents of obligation is decided by the construction of cont-ract. Therefore, the construction of contract has very important meaning for the decision of the contents of obligation. And the Civil Law of Korea includes provisions to settle disputes related to contract, and most of these provisions have the nature of voluntary law. And when there is no intention of the contracting parties, or it is not clear, the voluntary law comes into application(Civil code art. 105). Ultimately, voluntary law not only becomes the standard of the construction of the contract, but also it is applied as the law to settle dispute. Thus, it needs to clear what is the relation between the construc-tion of contract and the application of law. Therefore, this paper aims to clarify the relationship between the construction of contract and the appli-cation of law.