• 한국가시화정보학회지
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• 제4권1호
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• pp.8-13
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• 2006

Fire simulation has been developed for decades to analyze fire cases and provide a tool to study fundamental fire dynamics and combustion. There are three way of fire simulation which are a full scale simulation, an experimental simulation and a computational simulation. In case of a full scale simulation, because a higher cost, a higher risk, more efforts are needed, a demand for it has been decreased. But recently a demand for an experimental simulation and a computational simulation has been increased. A computational simulation has several advantages; lower cost, short period, many case studies, more visual results, a quantitative result and etc. FDS(Fire Dynamics Simulator) which has been developed in BFRL(Building and Fire Research Laboratory), NIST(National Institute of Standards and Technology) is a popular world wide code for fire simulation. Lack of accurate predictions by the model could lead to erroneous conclusions with regard to fire safety. All results should be evaluated by the informed judgment of the qualified user.

• Structural Engineering and Mechanics
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• 제48권3호
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• pp.309-331
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• 2013

An integrated superelement concept is proposed to improve the computational efficiency when analyzing structural responses during progressive collapses of large-scale structures, such as multi-storey reinforced concrete buildings. While the proposed methodology is straightforward and can be implemented into an existing finite element program with little effort, it is able to significantly reduce the computational cost without the loss of any critical information of the structural responses. Compared with the models without superelement, significant saving in computational cost and satisfactory prediction accuracy can be obtained with the proposed approach.

• Computers and Concrete
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• 제23권5호
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• pp.311-320
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• 2019

The substructuring technique is one of the efficient methods for reducing computational effort and memory usage in the finite element method, especially in large-scale structures. Proper mesh partitioning plays a key role in the efficiency of the technique. In this study, new algorithms are proposed for mesh partitioning based on an element search technique. The computational cost function is optimized by aligning each element of the structure to a proper substructure. The genetic algorithm is employed to minimize the boundary nodes of the substructures. Since the boundary nodes have a vital performance on the mesh partitioning, different strategies are proposed for the few number of substructures and higher number ones. The mesh partitioning is optimized considering both computational and memory requirements. The efficiency and robustness of the proposed algorithms is demonstrated in numerous examples for different size of substructures.

• 전산구조공학
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• 제26권3호
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• pp.47-51
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• 2013

• 한국전산유체공학회지
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• 제22권1호
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• pp.51-58
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• 2017

A penalized VIC method offers an efficient hybrid particle-mesh algorithm to simulate an incompressible viscous flow passing a solid body in an infinite domain. In this manner, the computational domain needs to be restricted to a relatively small region to reduce computational cost which would be very high in case of using a large domain. In this paper, we present how to dispose of far-field particles to avoid an unnecessarily large computational domain. The present approach constraints expansion of the domain and thus prevents the incremental computational cost. To validate the numerical approach, a flow around an impulsively started sphere was simulated for Reynolds numbers of 100 and 1000.

• 한국전산구조공학회논문집
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• 제15권4호
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• pp.557-566
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• 2002

본 논문에서는 강상자형교의 바닥판과 주형에 대한 생애주기비용(Life-Cycle Cost : LCC)를 고려한 최적설계 방법을 제안하였다. 생애주기비용의 최적설계 문제는 초기비용, 유지관리비용 그리고 강도와 처짐 그리고 균열에 대한 파손 기대비용의 최소화 문제로 정식화할 수 있다. 기존의 재래적인 설계방법과의 비교를 동해서 강상자형교의 생애주기비용 최적설계의 우수성을 입증하였다. 또한 수치적인 결과의 고찰을 통하여 LCC에 근거한 최적설계가 여타의 설계방법들보다 좀 더 합리적이고 경제적이며 안전한 설계를 유도하는 것으로 분석되었다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1994년도 가을 학술발표회 논문집
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• pp.152-159
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• 1994

One of the main objectives of the study is to propose a pratical and realistic reliability analysis by ETCM(Expected Total Cost Minimization). This study is intended to propose the safety assesment and capacity rating of existing reinforced concrete members by evaluating the safety evaluation index, that is RF(Rating Factor) from the results of the field test and inspection for 5 reinforced concrete bridges. ETCM method is used for the reliability analysis of the proposed models. The proposed reliability model and method are applied the safety assesment and system factors of reinforced concrete members.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1990년도 가을 학술발표회 논문집
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• pp.101-104
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• 1990

The program which could determine cross-sectional dimensions of the box girder bridge at tile stage of preliminary design was developed using the optimal technique in this study. It could minimize the cost and time required in the design of box girder bridges and the construction with the prestressed precast segmental method. Objective cost function consisted of four independent variables such as widths and depth of the cross-section. The Nelder-Mead method was used to solve the nonconstrained nonlinear problem like this.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2004년도 가을 학술발표회 논문집
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• pp.339-346
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• 2004

This paper presents a method to minimize Life-Cycle Cost(LCC) of steel box girders. The LCC function considered in this paper includes initial cost, expected life-cycle maintenance cost and repair cost. A resistance force curve is derived from a condition grade curve of steel girders and optimal design of steel box girders is performed on the basis of derived resistance force curve. Also, in this paper annual costs of various case in LCC are compared and analyzed. It is concluded that the optimal design of steel box girders considering LCC by a presented method will lead to more economical and safer girders than conventional design.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2001년도 가을 학술발표회 논문집
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• pp.201-210
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• 2001

In this study, large-scale distributed design approach for a life cycle cost (LCC) optimization of steel box girder bridges was implemented. A collaborative optimization approach is one of the multidisciplinary design optimization approaches and it has been proven to be best suited for distributed design environment. The problem of optimum LCC design of steel box girder bridges is formulated as that of minimization of the expected total LCC that consists of initial cost maintenance cost expected retrofit costs for strength, deflection and crack. To discuss the possibility of the application for the collaborative optimization of steel box girder bridges, the results of this algorithm are compared with those of single level algorithm. From the numerical investigations, the collaborative optimization approach proposed in this study may be expected to be new concepts and design methodologies associated with the LCC approach.