• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2005년도 춘계 학술발표회 논문집
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• pp.151-158
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• 2005

For the safety analysis of large structures such as nuclear containment buildings, we conventionally prefer to use analytical approach using finite element method rather than empirical test. Therefor, this paper is mainly focused to develop low-order solid finite element model with the elasto-plastic material model for the safety analysis of nuclear containment building. Drucker-Prager failure criteria in uncracked concrete and maximum tensile stress criteria in cracked concrete are used to model the constitutive behavior of concrete. The concrete material model takes into account the aspects of tensile strain, compression strength reduction of concrete and shear transfer to improve the accuracy of the finite element analysis. Finally, numerical simulation to compare the performance of the developed model with experimental results is employed. The numerical results in this study agree very well with the experimental data.

• 전산구조공학
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• 제1권1호
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• pp.79-85
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• 1988

제2계 2차모멘트법인 점적합 포물체 근사법의 역과정의 연산을 구하여 신뢰성설계에 적용할 수 있도록 하였으며, 파괴점을 구하기 위한 신뢰성조건법을 연산과정을 수정하여 한계상태함수가 비선형인 경우에도 문제마다 식을 새로 수립하는 번거로움을 피하도록 하였다. SOSM/RC 조합방법을 이용하면 결과적인 파괴확률은 목표파괴확률에 부합하며 넓은 범위의 하중비에 대해 거의 일정한 부분안전계수를 얻을 수 있다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표대회 논문집(III)
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• pp.706-711
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• 1998

Structural tests of the PSC Beam bridge using high strength concrete, concrete compressive strength 700kg/$\textrm{cm}^2$, are conducted for the application including durability and serviceability of the bridge. Current design safety factors with respect to the jacking force and the service design load DB-24 are applied to the design of the bridge. Concrete compressive strength 700kg/$\textrm{cm}^2$, girder depth 2.3m, girder space 3.2m, span length 20m, and slab thickness 27cm are selected for the bridge test. The Bulb-Tee section of the girders is applied instead of I section because it is well known more stable to the longer span(40m). Static load test(4 beams) with composite and non-composite section, and fatigue load test(1 beams) with composite section are conducted. Crack moment, ultimate load, deflections with load steps, and strains of the beam section for those bridges are investigated. The structural test results of the bridges showed a good performance for a safety and a serviceability.

• 한국구조물진단유지관리공학회 논문집
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• 제2권4호
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• pp.194-200
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• 1998

Risk, probability of failure, which includes various uncertainties and influential factors of performance should be accounted for in engineering system. Recently, several different methods to analysis risk evaluation evolved and one of the practical method is FOSM (First Order Second Moment Method ). FOSM method is derived in terms of terms coefficient of variance to uncertainties which influence various factor. For risk evaluation and uncertainty analysis in hydraulic design system, load-capacity relationship is adopted in this paper. Sample catchment with design of sewer system is applied, which plots safety factor vs. risk. Risk evaluation and uncertainty analysis are very to important develop optimal design model in hydraulic system

• 한국공간구조학회논문집
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• 제19권3호
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• pp.77-83
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• 2019

AU(A plus U-shaped) composite beam was developed for reducing the story height in the residential buildings, and saving the cosrtuction cost of floor structures. Structural performance and economic feasibility of the composite beam have been sufficiently approved through the structural experiments and the analytical studies. Fire safety for the practical application of the composite beam has also been verified through the fire resistance tests and the heat transfer analyses. In this study 2-points bending tests were performed on the four specimens already tested for fire resistance to evaluate the residual bending strength of AU composite beam after fire accident. The same bending test was performed on the one fresh specimen having the same section and span of the specimens for practically comparative study.

• Structural Monitoring and Maintenance
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• 제2권3호
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• pp.269-282
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• 2015

Civil structures should be designed with the lowest cost and longest lifetime possible and without service failure. The efficient and sustainable use of materials in building design and construction has always been at the forefront for civil engineers and environmentalists. Timber is one of the best contenders for these purposes particularly in terms of aesthetics; fire protection; strength-to-weight ratio; acoustic properties and seismic resistance. In recent years, timber has been used in commercial and taller buildings due to these significant advantages. It should be noted that, since the launch of the modern building standards and codes, a number of different structural systems have been developed to stabilise steel or concrete multistorey buildings, however, structural analysis of high-rise and multi-storey timber frame buildings subjected to lateral loads has not yet been fully understood. Additionally, timber degradation can occur as a result of biological decay of the elements and overloading that can result in structural damage. In such structures, the deficient members and joints require strengthening in order to satisfy new code requirements; determine acceptable level of safety; and avoid brittle failure following earthquake actions. This paper investigates performance assessment and damage assessment of older multi-storey timber buildings. One approach is to retrofit the beams in order to increase the ductility of the frame. Experimental studies indicate that Sprayed Fibre Reinforced Polymer (SFRP) repairing/retrofitting not only updates the integrity of the joint, but also increases its strength; stiffness; and ductility in such a way that the joint remains elastic. Non-linear finite element analysis ('pushover') is carried out to study the behaviour of the structure subjected to simulated gravity and lateral loads. A new global index is re-assessed for damage assessment of the plain and SFRP-retrofitted frames using capacity curves obtained from pushover analysis. This study shows that the proposed method is suitable for structural damage assessment of aged timber buildings. Also SFRP retrofitting can potentially improve the performance and load carrying capacity of the structure.

• 한국구조물진단유지관리공학회 논문집
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• 제21권5호
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• pp.30-41
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• 2017

소음 저감을 목적으로 설치되는 방음벽은 크게 흡음판과 방음판으로 나뉘며, 일조 및 경관을 저해하는 방음벽의 문제점을 해결하고자 투명 방음벽을 설치하는 것이 일반적 추세이다. 방음벽에 사용되는 투명 방음판의 소재는 여러 가지가 있으나 경우에 따라서는 황변현상과 재질변형 등으로 인해 투명도가 떨어지고 오염이 심해져 오히려 도시미관을 해하기도 한다. 따라서 이러한 단점을 보안하기 위하여 투명 방음판의 재질을 접합강화유리로의 대체가 가능하다. 본 논문은 메트로 지하철 고가교 상에서의 열차 유발진동에 따른 접합강화유리 방음판의 진동 및 풍하중에 의한 안전성을 분석하고, 접합강화유리 시스템 및 재료에 대한 휨능력 성능시험, 압축강도 및 탄성계수 시험, 충격시험 등을 수행하여 접합강화유리의 방음판으로서의 적정성을 평가하는 데 목적이 있다.

• 한국구조물진단유지관리공학회 논문집
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• 제22권2호
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• pp.34-42
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• 2018

아스팔트 콘크리트 궤도(ACT)의 변형을 최소화하고 구조적 안전성을 확보하기 위해서는, 열차 하중을 분산 및 저감시킬 수 있고 아스팔트 도상의 노출을 줄일 수 있는 광폭 형태의 콘크리트 침목이 필요하다. 본 연구에서는 형상 설계를 통해 아스팔트 콘크리트 궤도용 광폭 PSC침목을 개발하였으며, 유한요소해석을 통해 레일 좌면부 및 침목 중앙부에 대한 구조 안전성을 검토하였다. 또한 아스팔트 콘크리트 궤도용 광폭 PSC침목의 설계 적합성을 검증하기 위하여, EN 13230-2에 의거 침목 주요 위치별로 정적 휨 강도 시험, 동적 휨 강도 시험 및 피로 시험을 수행하였다. 성능 시험 결과, 아스팔트 콘크리트 궤도용 광폭 PSC침목은 균열 하중, 파괴 하중, 및 균열 확대 여부 등 유럽 표준에서 요구되는 성능 기준을 모두 충족하였다.

• 국제초고층학회논문집
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• 제6권3호
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• pp.217-226
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• 2017

This paper summarizes the structural concept and design of the "Nakanoshima Festival Tower West" in Osaka, Japan, which is 200m high and has a super-high damping system. Its superstructure is mainly composed of a central core and outer tube frames. It has a bottom truss structure at the boundary between the low-rise and mid-rise sections of the building, where the column arrangement is changed. Besides, the high-rise section of the building has a neck truss structure. These truss structures smoothly transfer the axial forces of the columns and reduce the flexural deformations induced by horizontal loads. Oil dampers with extremely high damping capacity are installed in the rigid walls named the "Big Wall Frames" of the low-rise section. Moreover, many braces and damping devices are well arranged in the center core of each story. The damping effects of these devices ensure that all structural members are remain within the elastic range and that story drifts are within 1/150 in large earthquakes. This super-high damping structure in the low-rise section is named the "Damping Layer". The whole structural system is named the "Super Damping Structure". The whole structural systems enhance the building's safety, comfort and Business Continuity Planning (BCP) under large earthquakes.

• 한국도로학회논문집
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• 제15권4호
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• pp.127-133
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• 2013

PURPOSES : The impact performance of flexible barrier system such as structural response, vehicular motion and occupant safety vary depending on the impact point. Thus, to properly evaluate the performance of a flexible barrier system, impact should be made to a point which will lead to the worst possible results. This point is called the Critical Impact Point (CIP). This paper presents the way to determine the CIP for a SB2 class flexible barrier system which is consisted of Thrie-Beam rail and circular hollow tube post of 2m span. METHODS: Barrier VII simulations were made for impact points; Case 1 at a post, Case 2 at 1/3 span downstream from a post, Case 3 at middle of the span, Case 4 at 2/3 span downstream from a post. For the structural performance (deflections), impact simulation of 8000kg-65km/h-15degree was used, and for vehicle motion and occupant safety, simulation of 1300kg-80km/h-20degree impact was made and analysed. RESULTS: Case 1 gave the largest dynamic deflection of 75.72cm and also gave the largest snag value of 44.3cm. Occupant safety and exit angle of the vehicle after the impact were not sensitive to the impact point and were all below the allowable limit. CONCLUSIONS : For the SB2 class flexible barrier system's CIP can be regarded as a post which is sufficiently away from the end of Length of Need in order to avoid the end-effect of the barrier system. It can be more economic in the long run because the normal concrete pavement material is likely to cost more due to higher probability of maintenance and repair and higher social cost due to traffic accident, etc.