• Title/Summary/Keyword: Optimum structural design

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A Study on the New Method for Structural Analysis and Design by MDO(Multidisciplinary Design Optimization) Methodology : Application to Structural Design of Flap Drive System (MDO기법에 의한 새로운 구조해석 및 설계기법 고찰: 플랩 구동장치의 구조설계에의 적용)

  • 권영주;방혜철
    • Korean Journal of Computational Design and Engineering
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    • v.5 no.2
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    • pp.184-195
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    • 2000
  • MDO (Multidisciplinary Design Optimization) methodology is an emerging new technology to solve a complicate structural analysis and design problem with a large number of design variables and constraints. In this paper MDO methodology is adopted through the use of computer aided systems such as Geometric Solid Modeller, Mesh Generator, CAD system and CAE system. And this paper introduces MDO methodology as a new method for structural analysis and design through the application to the structural design of flap drive system. In a MDO methodology application to the structural design of flap drive system, kinetodynamic analysis is done using a simple aerodynamic analysis model for the air flow over the flap surface instead of difficult aerodynamic analysis. Simultaneously the structural static analysis is done to obtain the optimum structural condition. And the structural buckling analysis for push pull rod is also done to confirm the optimum structural condition (optimum cross section shape of push pull rod).

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A hybrid simulated annealing and optimality criteria method for optimum design of RC buildings

  • Li, Gang;Lu, Haiyan;Liu, Xiang
    • Structural Engineering and Mechanics
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    • v.35 no.1
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    • pp.19-35
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    • 2010
  • This paper proposes a hybrid heuristic and criteria-based method of optimum design which combines the advantages of both the iterated simulated annealing (SA) algorithm and the rigorously derived optimality criteria (OC) for structural optimum design of reinforced concrete (RC) buildings under multi-load cases based on the current Chinese design codes. The entire optimum design procedure is divided into two parts: strength optimum design and stiffness optimum design. A modified SA with the strategy of adaptive feasible region is proposed to perform the discrete optimization of RC frame structures under the strength constraints. The optimum stiffness design is conducted using OC method with the optimum results of strength optimum design as the lower bounds of member size. The proposed method is integrated into the commercial software packages for building structural design, SATWE, and for finite element analysis, ANSYS, for practical applications. Finally, two practical frame-shear-wall structures (15-story and 30-story) are optimized to illustrate the effectiveness and practicality of the proposed optimum design method.

Development of Integrated Environment for Optimum Design Using Motif (모티프를 이용한 최적설계 통합환경 개발)

  • Lim, O-Kang;Cho, Heon;Kim,Young-Hyun;Lee, Byung-Woo
    • Computational Structural Engineering
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    • v.9 no.3
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    • pp.97-105
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    • 1996
  • An integrated environment for optimum design has been developed using Motif. The integrated environment is composed of the preprocessor, the postprocessor and the optimization part. The preprocessor is part of making a finite element model for optimum structural design and the postprocessor displays results of optimum design and the optimization part is the part which execute optimization. It is designed to reduce user's difficulties in structural optimum design. It used Graphic User Interface for the concurrent representation of various inputs and outputs through the dialog box, mouse and keyboard. Structural optimum design can be done easily through dialog box, menu, concurrent representation of modeling process and results of structural optimum design can be understood easily through stress contour, deformed model and graph of cost function.

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Optimum Structural Design of Mid-ship Section of D/H Tankers Based on Common Structural Rules (CSR 을 활용한 이중선각유조선 중앙단면의 최적구조설계)

  • Na, Seung-Soo;Jeon, Hyoung-Geun
    • Journal of the Society of Naval Architects of Korea
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    • v.45 no.2
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    • pp.151-156
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    • 2008
  • It is necessary to perform the research works on the general structural designs and optimum structural designs of double hull tankers and bulk carriers due to the newly built Common Structural Rules(CSR). In this study, an optimum structural design of a mid-ship part of double hull oil tanker was carried out by using the CSR. An optimum structural design program was developed by using the Pareto optimal based multi-objective function method. The hull weight and fabrication cost obtained by the single and multi-objective function methods were compared with existing ship by the consideration of CSR and material cost which is recently increasing.

Structural design optimization of racing motor boat based on nonlinear finite element analysis

  • Song, Ha-Cheol;Kim, Tae-Jun;Jang, Chang-Doo
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.2 no.4
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    • pp.217-222
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    • 2010
  • Since 1980's, optimum design techniques for ship structural design have been developed to the preliminary design which aims at minimum weight or minimum cost design of mid-ship section based on analytic structural analysis. But the optimum structural design researches about the application for the detail design of local structure based on FEA have been still insufficient. This paper presents optimization technique for the detail design of a racing motor boat. To improve the performance and reduce the damage of a real existing racing boat, direct structural analyses; static and non-linear transient dynamic analyses, were carried out to check the constraints of minimum weight design. As a result, it is shown that the optimum structural design of a racing boat has to be focused on reducing impulse response from pitching motion than static response because the dynamic effect is more dominant. Optimum design algorithm based on nonlinear finite element analysis for a racing motor boat was developed and coded to ANSYS, and its applicability for actual structural design was verifed.

Reliability-Based Optimization of Continuous Steel Box Girder Bridges (신뢰성에 기초한 강상형 연속교의 단면 최적설계)

  • 조효남;이두화;정지승;민대홍
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1997.10a
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    • pp.145-154
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    • 1997
  • The results of optimum design by the deterministic approach adopted in the current design codes depend upon the safety levels of the applied code. But, it is now generally recognized that structural problems are nondeterministic and, consequently, that engineering optimum design must cope with uncertainties. Therefore, it is not an overstatement to affirm that the combination of reliability-based design procedures and optimization techniques is the only means of providing a powerful tool to obtain a practical optimum design solution. In the paper, reliability based optimum design procedure as a rational approach to optimum structural design is presented. The design constraints are formulated based on the ASD, LRFD and reliability theories. The reliability analysis is based on an advanced first-order second moment approach. Uncertainties in the structural strength and loading due to inherent variability as well as modeling and prediction errors are included in failure due to combined bending and shear. For the realistic reliability-based optimization of continuous steel box girder bridges, interactive non-linear limit state model is formulated based on the von Mises's combined stress yield criterion. Comparative results are presented when the ASD criteria are used for the optimum design of a structure under reliability constraints. In addition, this study comparatively shows the results of the optimum design for various criteria of design codes.

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Reliability Optimum Design of Slab System based on Lagrange Multipliers (Lagrange Multipliers에 의한 슬래브시스템의 신뢰성 최적설계)

  • Kim, Hyeon-Seak;Lee, Jeung-Bin;Jung, Chul-Won
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.1 no.1
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    • pp.113-124
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    • 1997
  • Based on the recent developments of the reliability-based structural analysis and design as well as the extending knowledge on the probabilistic characteristics of load and resistances, the probability based design criteria have been successfully developed for many standards. Since the probabilistic characteristics depend highly on the local load and resistances, it is recognized to develop the design criterion compatible with domestic requirements. The existing optimum design methods, which are generally based on the structural theory and certain engineering exprience, do not realistically consider the uncertainties of load and resistances and the basic reliability concepts. This study is directed to propose a optimum design based Expected Total Cost Minimization on two-way slab system which could possibly replace optimum design based traditional provisions of the current code, based on the AFOSM reliablity theory.

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A Study on Optimum Reliability of P.S.C Box Girder Bridge (최적신뢰성에 의한 P.S.C Box Girder교의 연구)

  • Jung, Chul-Won;Yu, Han-Shin;Na, Ki-Hyun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.3 no.4
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    • pp.139-144
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    • 1999
  • Based on the recent developments of the reliability-based structural analysis and design as well as the extending knowledge on the probabiliistic characteristics of load and resistances, the probability based design criteria have been successfully developed for many standards. Since the probabilistic characteristics depend highly on the local load and resistances, it is recognized to develop the design criterion compatible with domestic requirements. The existing optimum design methods, which are generally based on the structural theory and certain engineering experience, do not realistically consider the uncertainties of load and resistances and the basic reliability concepts. This study is directed to propose a optimum design based Expected Total Cost Minimization on P.S.C Box Girder Bridge system which could possibly replace optimum design based traditional provisions of the current code, based on the Neldel-Mead Method reliability theory.

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Simulated Annealing Algorithm for Optimum Design of Space Truss Structures (입체 트러스구조물의 최적설계를 위한 SA기법)

  • 정제원;박효선
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1999.04a
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    • pp.102-109
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    • 1999
  • Two phase simulated annealing algorithm is presented as a structural optimization technique and applied to minimum weight design of space trusses subjected to stress and displacement constraints under multiple loading conditions. Univariate searching algorithm is adopted for automatic selection of initial values of design variables for SA algorithm. The proper values of cooling factors and reasonable stopping criteria for optimum design of space truss structures are proposed to enhance the performance of optimization process. Optimum weights and design solutions are presented for two well-blown example structures and compared with those reported in the literature.

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Optimum Design System of Port Structures (항만구조물 최적설계 시스템)

  • 이상호
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1994.10a
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    • pp.79-86
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    • 1994
  • These days much efforts have made all over the world in order to develop the integrated optimum structural design system that performs automated design process composed of the analysis, optimum design, drafting, and reporting. However, these types of design systems oriented extensively to port structures are rarely found. In this paper, the integrated optimun design system applied to gravity type port structures such as quay walls and breakwaters will be briefly presented. Highly sophiscated facilities necessary in optimum structural design including analysis and optimization are integrated into one system. Several types of gravity type port structures can be designed using this system. The application to the real ports and the efficiency of this system will be finally shown.

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