• 해양환경안전학회지
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• 제26권3호
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• pp.286-296
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• 2020

Sandwich structures are general-purpose structures that can reduce the structural weight of composite ships. Core materials are essential for these structures, with polyvinyl chloride (PVC) foams being the most popular. These foam core materials are subjected to various tests in the development process, and must satisfy the performance requirements of several ISO and ASTM standards. Therefore, a procedure for evaluating the performance of foam core materials was proposed in this paper. In addition, prototypes were fabricated using a commercial PVC foam core product in accordance with the structural design of an 11 m fiber-reinforced plastic yacht. Then, a case study was conducted on the proposed evaluation procedure. The proposed procedure facilitates the understanding of the performance requirements and evaluation of core materials used in composite ships and is expected to be utilized in developing core materials for marine structures.

• 한국전산구조공학회논문집
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• 제24권5호
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• pp.499-506
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• 2011

본 연구에서는 컴퓨터 시뮬레이션을 통해 복합소재 교량용 방호울타리의 성능을 분석하였다. 복합소재 방호울타리는 SB4등급을 선정하였다. 복합소재의 적층을 고려하기 위해 LS-DYNA에서 제공하는 재료모델 MAT58을 사용하였다. 복합소재는 섬유와 수지의 종류 및 섬유의 방향에 따라 성능이 상이하다. 수지는 폴리우레탄, 섬유는 유리섬유를 사용하였다. 본 논문에서는 섬유의 방향성이 다른 3가지 적층 설계안에 대해서 충돌 시뮬레이션을 수행하여 성능을 비교 평가하였다. 실차충돌 실무 업무편람에 따라 구조적 강도성능, 탑승자 보호성능, 충돌 후 차량의 거동, 가드레일의 비산에 대한 성능 평가를 실시하였다. 그 결과 적층 설계의 횡 방향 섬유의 양이 많아질수록 충돌 시뮬레이션에서 더 좋은 성능을 나타내었다.

• 한국구조물진단유지관리공학회 논문집
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• 제26권6호
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• pp.182-192
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• 2022

취성파괴는 구조물의 파괴거동 중 하나로서 구조재료의 내진성능에 큰 영향을 미친다. 하중속도는 취성파괴의 주요 발생원인 중 하나로 작용하며, 특히 지진과 같은 상황에서 건축물에 높은 하중속도가 작용하게 된다. 하지만 현재 국내·외 강구조 보-기둥 접합부의 내진성능평가는 대부분 정적실험을 통해 수행되고 있다. 따라서 기존 내진성능평가에서는 지진 시의 높은 하중속도에 의한 재료 인성 저하 및 최대변형률 감소 등의 요소에 따른 취성파괴가 충분히 고려되지 않았을 가능성이 존재한다. 본 연구에서는 기존 실험방법에 따른 낮은 하중속도에서의 정적실험과 진동대를 이용한 높은 하중속도에서의 동적실험을 각각 실시한다. 각 실험결과에 따른 파괴형상 및 구조성능 등을 비교·분석하고 최종적으로 하중속도의 크기가 접합부의 내진성능에 미치는 영향을 분석한다.

• Structural Monitoring and Maintenance
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• 제3권1호
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• pp.51-69
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• 2016

Monitoring the performance and estimating the remaining useful life of aging civil infrastructure in the United States has been identified as a major objective in the civil engineering community. Structural health monitoring has emerged as a central tool to fulfill this objective. This paper presents a review of the major structural monitoring programs that have been recently implemented in the United States, focusing on the integrity and performance assessment of large-scale structural systems. Applications where response data from a monitoring program have been used to detect and correct structural deficiencies are highlighted. These applications include (but are not limited to): i) Post-earthquake damage assessment of buildings and bridges; ii) Monitoring of cables vibration in cable-stayed bridges; iii) Evaluation of the effectiveness of technologies for retrofit and seismic protection, such as base isolation systems; and iv) Structural damage assessment of bridges after impact loads resulting from ship collisions. These and many other applications show that a structural health monitoring program is a powerful tool for structural damage and condition assessment, that can be used as part of a comprehensive decision-making process about possible actions that can be undertaken in a large-scale civil infrastructure system after potentially damaging events.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.413-420
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• 2006

There are many Korean traditional wooden structures that have resisted successfully over more than several hundred years. However, their structural behavior is not known in engineering context yet. It is then difficult to predict how they behave against various loadings if they face. This paper is to attempt to investigate structural performance of the wooden structures using fuzzy concepts rather than definitely defined engineering formula. The fuzzy synthetic theory to a scoring method enables us to draw a representative and comprehensive value from individual quantity.

• 대한안전경영과학회지
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• 제23권4호
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• pp.67-72
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• 2021

To ensure the safety and functionality of a railroad bridge, maintaining the integrity of the bridge via continuous structural health monitoring is important. However, most structural integrity monitoring methods proposed to date are based on modal responses which require the extracting process and have limited availability. In this paper, the applicability of the existing damage identification method based on free-vibration reponses to time-domain deflection shapes due to moving train load is investigated. Since the proposed method directly utilizes the time-domain responses of the structure due to the moving vehicles, the extracting process for modal responses can be avoided, and the applicability of structural health evaluation can be enhanced. The feasibility of the presented method is verified via a numerical example of a simple plate girder bridge.

• 한국BIM학회 논문집
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• 제11권3호
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• pp.34-44
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• 2021

This study quantitatively analyzes the work performance of the structural safety diagnosis team that diagnoses pipe racks. To this end, a method for evaluating the performance of the structural safety diagnosis team using the queuing model was proposed. For verification, the case of applying the existing method and the method of introducing a 3D laser scanner for one site was used. The period, number of people, and initial investment cost of each project were collected through interviews with case project experts. As a result of analyzing the performance of the structural safety diagnosis team using the queuing model, it was possible to confirm the probability of delay in the work of each project and the amount of delayed work. Through this, the cost (standby cost) when the project was delayed was analyzed. Finally, economic analysis was conducted in consideration of the waiting cost, labor cost, and initial investment cost. The results of this study can be used to decide whether to introduce 3D laser scanners.

• 한국구조물진단유지관리공학회 논문집
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• 제23권6호
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• pp.70-76
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• 2019

본 논문은, 시설물안전법의 적용을 받지 않아 안전사각 지대에 놓여 있는 중소규모 교량들의 유지관리 전략 수립시 기초자료로 활용할 수 있는, 중소규모 교량 성능평가 우선순위 결정 방안을 제시하기 위해 실시하였다. 이를 위해 취약도와 영향도를 기반으로 하는 위험도 지수를 산출하고, 산출된 위험도 지수에 따라 이들 교량들을 성능평가 즉시실시교량, 단기실시교량 및 관찰교량으로 구분하여 제안하고, 실제 공용중에 있는 중소규모 교량에 적용하여 제안한 방안의 현장 적용성을 확인하였다. 연구결과, 여기서 제시된 방안은 향후 중소규모 교량의 유지관리 전략 수립에 적절히 활용되어 중소규모교량 사고 방지 및 유지관리 예산절감에 기여할 수 있을 것으로 판단되었다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.275-282
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• 2007

In this study, a fluid-structure interaction (FSI) analysis system has been developed in order to evaluate the turbine cascade performance with blade structural deformation effect. Relative movement of the rotor with respect to stator is reflected by modeling independent two computational domains. To consider the deformed position of rotor airfoil, dynamic moving grid method is applied. Reynolds-averaged Navier-Stokes equations with one equation Spalart-Allmaras and two-equation SST $k-{\varepsilon}$ turbulence models are solved to predict unsteady fluid dynamic loads. A fully implicit time marching scheme based on the Newmark direct integration method with high artificial damping is used to compute the fluid-structure interaction problem. Cascade performance evaluations for different elastic axis positions are presented and compared each other. It is importantly shown that the predicted aerodynamic performance considering structural deformation effect of blade can show some deviations compared to the data generally computed from rigid blade configurations and the position of elastic axis also tend to give sensitive effect.

• 한국전산구조공학회논문집
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• 제22권1호
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• pp.15-23
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• 2009

압축력에 강한 석조 홍예아치교의 경우 재료적 음력한계보다는 구조적 형상의 불안정성에 의해서 구조물이 붕괴된다. 이러한 특성을 고려하면, 석조 홍예아치교의 구조적 안정성 평가에는 구조물의 붕괴기구 형상에 초점을 둔 한계상태 해석이 보다 적합하다. 이 연구에서는 한계상태 해석법을 이용하여 건식법(dry construction)으로 축조된 우리나라 석조 홍예아치교의 구조적 거동을 살펴보고, 이 결과를 구조적 안정성 평가시스템 개발에 이용하고자 한다. 이 연구결과는 우리나라 석조 홍예아치교의 구조적 거동을 이해하는데 도움이 되며, 향후 문화재 유지관리 측면에서 공학적 판단기준을 주리라 기대한다.