• Journal of the Korean Wood Science and Technology
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• 제36권4호
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• pp.58-65
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• 2008

집성재의 구조부재로서의 이용에 있어서는 접합철물(connector)과 파스너(fastener)에 의한 접합이 대부분을 차지하고 있다. 이들 접합부의 역학적 거동은 파스너의 지압과 부재의 전단현상으로 설명할 수 있다. 집성재 내의 층재 구성상태에 따른 전단성능, 2면전단 핀접합부의 인발에 의한 전단성능, 실대 기둥-보 2면전단 핀접합부의 모멘트 저항성능을 검토하였다. 집성접착된 부위의 경우, 두 층재간의 보완작용에 의해 밀도 및 전단강도에 있어서도 적층효과를 발휘하였다. 소시험편의 전단강도를 이용한 핀접합부의 2면전단강도와 모멘트 저항성능을 예측할 경우 다소의 보정이 필요할 것으로 판단되었다. 기둥-보 접합부의 모멘트저항성능 예측은 소시험편 전단강도의 10%를 저감하여 이용하면 안전하게 예측가능한 것으로 판명되었다.

• 국제강구조저널
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• 제18권5호
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• pp.1508-1524
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• 2018

Hysteretic energy dissipating devices (HEDDs) have been increasingly applied to building construction to improve the seismic performance. The seismic responses of such damped structures are significantly affected by HEDD's structural properties. An accurate investigation on the propagation of HEDD's structural properties is required for reasonable evaluation of the seismic performance of a structure. This study aims to develop simplified methods that can estimate the collective uncertainty-propagation to the seismic response of damped structures employing HEDDs. To achieve this, three- and six-story steel moment-resisting frames were selected and the propagations of the individual HEDD's property-uncertainties were evaluated when they are subjected to various levels of seismic demand. Based on the result of individual uncertainty-propagations, a simplified method is proposed to evaluate the variation of seismic response collectively propagated by HEDD's property-uncertainties and is verified by comparing with the exact collective uncertainty-propagation calculated using the Monte Carlo simulation method. The proposed method, called as a modified SRSS method in this study, is established from a conventional square root of the sum of the squares (SRSS) method with the relative contributions of the individual HEDD's property-uncertainty propagations. This study shows that the modified SRSS method provides a better estimation than the conventional SRSS method and can significantly reduce computational time with reasonable accuracy compared with the Monte Carlo simulation method.

• Earthquakes and Structures
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• 제22권6호
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• pp.561-570
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• 2022

It is of great importance to be able to evaluate different structural systems not only based on their seismic performance but also considering their lifetime service costs. Many structural systems exist that can meet the engineering requirements for different performance levels; therefore, these systems shall be selected based on their economic costs over time. In this paper, two structural systems, including special steel moment-resisting and the ordinary concentric braced frames, are considered, which are designed to meet the three performance levels: Immediate Occupancy (IO), Life Safety (LS), Collapse Prevention (CP). The seismic behavior of these two systems is studied under three strong ground motions (i.e., Tabas, Bam, Kajour earthquake records) using the Perform3D package, and the incurred damages to the studied systems are examined at two hazard levels. Economic analyses were performed to determine the most economical structural system to meet the specified performance level requirements, considering the initial cost and costs associated with damages of an earthquake that occurred during their lifetime. In essence, the economic lifetime study results show that the special moment-resisting frames at IO and LS performance levels are at least 20% more economical than braced frames. The result of the study for these building systems with different heights designed for different performance levels also shows it is more economical from the perspective of long-term ownership of the property to design for higher performance levels even though the initial construction cost is higher.

• 한국구조물진단유지관리공학회 논문집
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• 제6권2호
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• pp.135-143
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• 2002

This study is to investigate its use by applying stainless steel wire mash reinforcement method of construction, which is newly developed, on the high strength concrete beam mixed with polymer-steel fiber. In this test, it is investigated and observed such as follows: the ultimate load, the initial flexure crack load, the initial diagonal tension crack load, the relation between load and deflection, load-strain relation, and also crack growth and fracture aspect by increasing load. The results of this test are; first, the stainless steel wire showed some useful reinforcement effects in multiplying the steel's resisting force of moment to the tensile force of beam or slab: second, the promoting strength and internal force was made in the process of the integration at the same reaction by using the penetrating polymer-mortar with an excellent durability and physical property. On the basis of this results, because such instances in applying stainless steel wire Mash reinforcement method of construction have been few so far, through the experimental investigation such as this test over and over again, the efficient and useful method must be developed for the practice.

• Earthquakes and Structures
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• 제23권6호
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• pp.549-580
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• 2022

This paper assesses the influences of modeling assumptions and uncertainties on the performance of the non-linear finite element (FE) model updating procedure and model clustering method. The results of a shaking table test on a four-story steel moment-resisting frame are employed for both calibrations and clustering of the FE models. In the first part, simple to detailed non-linear FE models of the test frame is calibrated to minimize the difference between the various data features of the models and the structure. To investigate the effect of the specified data feature, four of which include the acceleration, displacement, hysteretic energy, and instantaneous features of responses, have been considered. In the last part of the work, a model-based clustering approach to group models of a four-story frame with similar behavior is introduced to detect abnormal ones. The approach is a composition of property derivation, outlier removal based on k-Nearest neighbors, and a K-means clustering approach using specified data features. The clustering results showed correlations among similar models. Moreover, it also helped to detect the best strategy for modeling different structural components.

• 한국지진공학회논문집
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• 제14권1호
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• pp.43-50
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• 2010

철근의 부식을 해결하기 위해 철근의 대체 재료로 적용 가능한 FRP에 대한 연구의 적용성이 대두되었다. 그러나 취성적인 성질과 탄성계수가 낮은 단점을 가지고 있어, FRP rebar로 보강된 휨 부재의 사용성 평가 즉 처짐에 대한 연구가 필요하다. 본 연구에서는 보강비를 변수로 한, CFRP rebar로 보강된 콘크리트 보의 휨 실험을 수행하였다. 실험 결과, CFRP rebar로 보강된 실험체는 보강비가 증가함에 따라 내력 및 강성이 증가하는 양상을 보였으며, 철근 실험체와 동일한 단면성능을 발휘하기 위해서는 약 1.3배의 보강비가 요구되는 것으로 나타났다. 또한 유효단면2차모멘트에 대한 기존 제안식의 비교 결과, Bischoff & Scanlon이 제안한 식이 가장 정밀해에 가까운 처짐을 예측하였다.