• 한국구조물진단유지관리공학회 논문집
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• 제12권5호
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• pp.125-132
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• 2008

구조최적화는 최근 CAD와 컴퓨터 기술이 발전하면서 구조설계부분에 널리 이용되고 있다. 본 연구에서는 30층의 강구조물을 대상으로 유한요소해석 및 어댑티브 시뮬레이티드 어닐링 알고리즘을 이용하여 최적중량설계를 구현하였다. 최적설계는 모든 설계상수와 설계하중들이 주어졌을 때, 목적함수가 최소로 됨과 동시에 모든 설계제약조건을 만족시키는 설계변수를 결정하는 설계법이라고 정의할 수 있다. 최적설계 구현을 통해 건설 측면에 있어 성능 향상과 신뢰도 향상 효과를 가져 올 수 있을 것이다.

• 전산구조공학
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• 제10권2호
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• pp.255-263
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• 1997

실제로 구조시스템들의 최적설계는 설계변수가 연속값이 아닌 이산값을 요하는 경우가 대부분이다. 본 논문은 이산형 설계변수를 갖는 비대칭 복합 적층평판에 대해 선형 근사화방법을 이용한 이산최적설계를 수행하였으며, 이 방법이 매우 효율적임을 보였다. 대상 문제는 축력, 전단력, 그리고 휨과 비틀림 모멘트의 평면 내하중들(in-plane loads)의 다중하중조건을 받는 것으로 고려하였으며, 복합 적층평판을 구성하는 플라이들에 대한 최대변형률 규준을 설계 제약조건으로 부과하였다. 이산 최적화를 위한 초기 접근방법으로 단 한번의 연속변수 최적화 과정이 FDM(Feasible Direction Method)을 이용하여 수행되었으며, 차후 이산 및 연속변수를 포함하는 비선형 이산최적화문제를 SLDP(Sequential Linear Discrete Programming)방법에 의해 선형 근사화된 혼합정수계획문제로 형성하여 풀었다. 수치예에서 6개의 플라이로 구성된 비대칭 복합 적층평판을 대상으로 회전식 적층배열([(90-.theta.)/-(60+.theta.)/-.theta./-(45+.theta.)/(45-.theta.)]/sub s/)에 따른 이산최적해를 구하였다. 효율성 입증을 위해 똑같은 문제를 비선형 분기한계법을 이용하여 풀었으며, 그 결과를 비교 분석하였다.

• 대한건축학회논문집:구조계
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• 제35권7호
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• pp.171-178
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• 2019

Auto Climbing Formwork System (ACS) for construction of high-rise building is a construction method for automatically lifting the formwork system supported by the anchor on the pre-constructed concrete wall. It has excellent construction speed and quality, but it has the possibility of structural failure depending on the quality of concrete and also has low economical efficiency due to the use of foreign technology. In order to overcome these problems, this study conducted an optimum design for the development of a new concept of Corner Supported Auto Climbing System (CS-ACS) in conjunction with the development of corner steel-reinforced concrete core wall system. For the design the formwork system, the basic module and structural member compositions were planned, and the structural analysis program was used to analyze the optimum member's cross section and spacing. As a result, the horizontal displacement and the stress of the horizontal members were influenced by the spacing more than the cross-section of the member. On the other hand, vertical members did not affect the displacement and stress of the formwork system. The form tie was very effective in controlling the displacement when adjusting the spacing of the horizontal members, but when the spacing of the form tie is more than 1,500mm, it is analyzed that form tie is yielding in basic module. When the span of the formwork system is more than 30m, it is analyzed that the basic module needs to be changed because of the increase of overall displacement.

• 대한조선학회 특별논문집
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• 대한조선학회 2005년도 특별논문집
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• pp.63-68
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• 2005

Optimum design of the big brackets is performed through iterated 3-D FE analyses to meet the permissible limits of stress, which consumes an excessive amount of calculation time. Therefore, this study has been prepared to determine rapidly and accurately an optimum size and scantling of the big brackets at the initial design stage. The generalized slope deflection method (GSDM) based on the span point concept is applied to enhance the efficiency of iterated structural analyses. The accuracy and applicability of the present method is verified by comparing with a detail 3-D FE analysis of web frame structures. As an optimization technique, evolution strategies (ES) are applied using discrete design variables for practical design.

• 한국해양공학회지
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• 제21권2호
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• pp.75-80
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• 2007

The design variables for structural systems, in most practical designs, are chosen from a list of discrete values, which are commercially available sizing. This paper presents the application of Genetic Algorithms for determining the optimum design for two-dimensional structures with discrete and pseudocontinuous design variables. Genetic Algorithms are heuristic search algorithms and are effective tools for finding global solutions for discrete optimization. In this paper, Genetic Algorithms are used as the method of Elitism and penalty parameters, in order to improve fitness in the reproduction process. Examples in this paper include: 10 bar planar truss and 1 bay 8-story frame. Truss with discrete and pseudoucontinuous design variables and steel frame with W-sections are used for the design of discrete optimization.

• 대한기계학회논문집A
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• 제32권3호
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• pp.258-266
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• 2008

The conventional approximate optimization method, which uses the statistical design of experiments(DOE) and response surface method(RSM), can derive an approximated optimum results through the iterative process by a trial and error. The quality of results depends seriously on the factors and levels assigned by a designer. The purpose of this study is to propose a new technique, which is called a sequential design of experiments(SDOE), to reduce a trial and error procedure and to find an appropriate condition for using artificial neural network(ANN) systematically. An appropriate condition is determined from the iterative process based on the analysis of means. With this new technique and ANN, it is possible to find an optimum design accurately and efficiently. The suggested algorithm has been applied to various mathematical examples and a structural problem.

• Journal of Welding and Joining
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• 제28권4호
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• pp.49-54
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• 2010

Stainless steel sheets are widely used as the structural material for the railroad cars and the commercial vehicles. These kinds structures used stainless steel sheets are commonly fabricated by using the GMAW (gas metal arc welding). For fatigue design of GMA welded joints such as fillet and plug, ring type joint, it is important to obtain optimum design factor information on GMA welded joints. in this paper, analysis approach for fatigue test using design of experiment are evaluated optimum factor in GMA welded joint type and geometrical parameters of materials. Using these results, that factors applied to fundamental information for fatigue design.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2000년도 가을 학술발표회논문집
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• pp.265-272
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• 2000

Unbond brace hysteretic dampers are generally used to prevent or decrease structural damage in buildings subjected to strong earthquake by its energy dissipating hysteretic behavior. According to a previous research, the optimum ratio of device yield strength to story yield strength of the combined system has been identified as the most important parameter for characterizing the performance of this device. In this research, the validity and the applicability of the previous research has been investigated and a new approach has been proposed through earthquake response analysis of a steel structure installed with unbond brace type hysteretic damper.

• 한국구조물진단유지관리공학회 논문집
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• 제21권6호
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• pp.16-24
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• 2017

본 논문은 오프셋 아웃리거의 최적위치를 알기 위하여 우선 아웃리거 구조시스템이 설치된 80층의 초고층건물을 대상으로 MIDAS-Gen을 이용하여 계획설계 수준의 구조설계를 실시하였다. 그리고 본 연구에서는 기둥의 강성, 아웃리거의 평면상 위치, 아웃리거의 설치 높이 등을 주요한 변수로 선택하여 구조해석을 진행하였다. 또한 초고층건물의 오프셋 아웃리거에 대한 최적위치를 찾는 것을 목적으로 초고층건물의 구조설계에서 가장 필수적인 최상층에서 발생하는 수평변위를 분석하였다. 본 연구의 결과, 기둥의 강성, 아웃리거의 평면상 위치, 아웃리거의 설치 높이는 아웃리거 구조시스템의 최적위치에 영향을 주는 것으로 나타났다. 또한 본 연구의 결과는 초고층건물의 오프셋 아웃리거 구조시스템의 최적위치를 알려주는 구조설계 자료로 유용하다고 사료된다.

• Wind and Structures
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• 제20권4호
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• pp.489-508
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• 2015

In this paper, a novel methodology is proposed to obtain optimum location of outriggers. The method utilizes genetic algorithm (GA) for shape and size optimization of outrigger-braced tall structures. In spite of previous studies (simplified methods), current study is based on exact modeling of the structure in a computer program developed on Matlab in conjunction with OpenSees. In addition to that, exact wind loading distribution is calculated in accordance with ASCE 7-10. This is novel since in previous studies wind loading distributions were assumed to be uniform or triangular. Also, a new penalty coefficient is proposed which is suitable for optimization of tall buildings. Newly proposed penalty coefficient improves the performance of GA and results in a faster convergence. Optimum location and number of outriggers is investigated. Also, contribution of factors like central core and outrigger rigidity is assessed by analyzing several design examples. According to the results of analysis, exact wind load distribution and modeling of all structural elements, yields optimum designs which are in contrast of simplified methods results. For taller frames significant increase of wind pressure changes the optimum location of outriggers obtained by simplified methods. Ratio of optimum location to the height of the structure for minimizing weight and satisfying serviceability constraints is not a fixed value. Ratio highly depends on height of the structure, core and outriggers stiffness and lateral wind loading distribution.