• Journal of Advanced Marine Engineering and Technology
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• 제32권6호
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• pp.915-922
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• 2008

The gas separation technology using membrane is widely used to refine various gases in many industry fields and recently is being applying in $CO_2$ recovery technology. In the gas and chemical tanker. nitrogen generators for inerting, purging and padding are on board and most of them have membrane modules of hollow fiber type with long life and vibration resisting properties. Because a membrane module is a key component accounting for 50% of total manufacturing cost of nitrogen generator, adequate selection for it is an important problem. In this paper, the flow performance coefficient based on dimension and specification data of membrane module was relatively selected to compare nitrogen generating capacity of module and various performance tests about the selected PARKER ST6010 membrane module were conducted. As a result, the useful coefficient and basic data in selecting a membrane module were achieved.

• Wind and Structures
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• 제12권2호
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• pp.89-101
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• 2009

The Monte Carlo procedure was used to simulate wind load effects on a light-frame low-rise structure of irregular shape and a main wind force resisting system. Two analytical models were studied: rigid-beam and rigid-plate models. The models assumed that roof diaphragms were rigid beam or rigid plate and shear walls controlled system behavior and failure. The parameters defining wall stiffness, including imperfections, were random and included wall stiffness, wall capacity and yield displacements. The effect of openings was included in the simulation via a set of discrete multipliers with uniform distribution. One and two-story buildings were analyzed and the models can be expanded into multiple-floor structures provided that the assumptions made in this paper are not violated.

• Computers and Concrete
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• 제22권1호
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• pp.11-25
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• 2018

A numerical approach for the evaluation of the flexural response of Steel Fibrous Concrete (SFC) cross-sections with arbitrary geometry, with or without conventional steel longitudinal reinforcing bars is proposed. Resisting bending moment versus curvature curves are calculated using verified non-linear constitutive stress-strain relationships for the SFC under compression and tension which include post-peak and post-cracking softening parts. A new compressive stress-strain model for SFC is employed that has been derived from test data of 125 stress-strain curves and 257 strength values providing the overall compressive behaviour of various SFC mixtures. The proposed sectional analysis is verified using existing experimental data of 42 SFC beams, and it predicts the flexural capacity and the curvature ductility of SFC members reasonably well. The developed approach also provides rational and more accurate compressive and tensile stress-strain curves along with bending moment versus curvature curves with regards to the predictions of relevant existing models.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.1248-1253
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• 2007

Urban transit or subway stations generally service for a long period of several decades. And, the urban transit or subway is public transportation which lots of people takes every day. During the service time, they are inevitably damaged from environmental corrosion, material aging, fatigue, and the coupling effects with long-term loads and extreme loads. The included damage accumulates and performance degenerates due to the above factors. They would inevitably reduce the resisting capacity of station against the disaster; even they result in collapse with the structural failure under extreme loads. And, if disaster such as earthquake, fire, etc. happens, it causes huge property damage and threatens the human lives. Because of these above reasons, the intelligent health surveillance system should be researched and developed for ensuring the safety of station. In this paper, the research plans of the intelligent health surveillance system of urban transit station are presented. And also, the development or establishment directions of this system are suggested.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.625-628
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• 2000

Recently, composite structural systems have been developed actively due to its structural advantages of combining different materials. The objective of this paper is to investigate the structural behavior of composite connection which consist of steel beams and reinforced concrete columns (RCS). Five 2/3 scale joint specimens with variables mainly consist of shear resisting details, were tested under reversal loads. The results showed that RCS beam-column joints maintain ductility, strength compared to other RCS joints and exhibited excellent energy dissipating capacity when subjected to inelastic deformations under reversal load.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1998년도 가을 학술발표회 논문집
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• pp.133-140
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• 1998

Material nonlinear analyses of RC(Reinforced Concrete) beams considering the tension stiffening effect and plastic hinge length have been conducted. Instead of taking the sophisticated layer approach which has some limitations in application to the large structures with many degrees of freedom. the moment-curvature relationships of RC sections previously constructed through the section analysis have been used. To reduce the numerical instability in nonlinear analysis and to remove the imprecision in calculation of ultimate resisting capacity, according to the used finite element mesh size, the tension stiffening effect and plastic hinge length have been taken into consideration. Finally, correlation studies between analytical and experimental results have been conducted with the objective to establish the validity of the proposed algorithms.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1996년도 가을 학술발표회 논문집
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• pp.401-407
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• 1996

A 2-bay 2-story moment-resisting reinforced concrete plane frame with seismic detail was designed. One 1/2.5-scale and one 1/10th model subassemblages were manufactured accoring to the required similitude law. Then the reversed load tests under the displacement control were performed statically to these subassemblages. The results of these tests were compared regarding to the similitude in the characteristics of structural behaviors such as strength., stiffness, energy dissipation, failure modes and local deformations. Based on these results, the following conclussions were drawn : (1) The strength of 1/10 model was very similar to that of 1/2.5 specimen. (2) The initial stiffness of 1/10 model appers to be approximately 2/3 of that of 1/2.5 specimen. (3) 1/10 model has therefore smaller energy dissipation capacity than 1/2.5 specimen. (4) Inelastic excursion mechanisms of 1/2.5 specimen and 1/10 model apper to be a little different.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(I)
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• pp.135-138
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• 2005

Since a ductile coupled shear wall system is the primary seismic load resisting systems of many structures, a coupling beams of these system must exhibit excellent ductility and energy absorption capacity. In this paper, the seismic response of coupled shear wall system is discussed. It includes that the evaluation of the degree of coupling between the shear walls and the coupling beams. It is demonstrated through a review of experimental investigations of coupling beam behavior that often the coupling beam ductility demand exceeds the expected available ductility. As a result, it is possible that coupled shear wall system will not behave as desired in the course of a significant seismic event. Limits to the allowable degree of coupling are proposed as a remedy to this apparent deficiency.

• Computers and Concrete
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• 제19권2호
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• pp.179-189
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• 2017

Concrete shear walls are one of the major structural lateral resisting systems in buildings. In some cases, due to the change in the occupancy of the structure or functional requirements like architectural and even mechanical ones, openings need to be provided and installed in structural walls after their construction. Providing these openings may significantly influence the structural behavior of the constructed wall. This paper considers the results of a nonlinear finite element analysis of shear walls with opening strengthened by carbon fiber reinforced polymer (CFRP) strips with different configurations. Details of bond-slip constitutive model of link elements to simulate the connections of FRP strips to concrete surface is presented. The proposed model in this research has been validated using experimental results available in the literature. The results indicated that the proposed configuration of CFRP strips significantly improved the lateral resistance and deformation capacity of the shear walls with opening.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.165-168
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• 2006

Carbon fiber reinforced polymer(CFRP) have superior mechanical and chemical properties in comparison with conventional materials. And post-tensioning method has been used for structural reinforcement of RC structures due to easy installation and good effect of resisting capacity of structures. But the higher cost of CFRP and the loss of prestressing force with time are considered the major problems to use it. In this study, CFRP Strips and external post tensioning for rehabilitation of old concrete structures were adapted and optimal combination of these methods is considered. A total of 17 concrete members were made and tested. The types and numbers of CFRP strips and post-tensioning types were selected as major test variables. From test results, it is shown that the concrete members that post tensioned and bonded CFRP strips has a pronounced effect on the strength and deformational behavior. This present study indicates that external temporally post tensioning can reduce the amount of CFRP strips required and the combination of temporally post tensioning and CFRP strips may meet the strength and ductility requirements of old structures.