• Title, Summary, Keyword: 축차무제약최소화기법

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Research on Variable Girder Types and Tendon Arrangement of PSC Box Girder Bridges by using the Optimum Design (최적설계에 의한 PSC 박스 거더교의 변단면 거더유형과 긴장재 배치에 관한 연구)

  • Kim, Ki-Wook
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.10 no.3
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    • pp.175-185
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    • 2006
  • This study performed the optimum design of balanced and unbalanced span length bridges with many variable Girder types by using the optimum design program to minimize the cost for PSC box girder bridge of the full staging method. The objective of this study is to present tendon's application direction about complicated construction hereafter by studying about optimum tendon arrangement that is worked in each variable Girder type. This program used SUMT procedure and Kavlie's extended penalty function to allow infeasible design points in the process. Powell's direct method was used in searching design points and Gradient Approximate Method was used to reduce design hours.

The Optimum Design for PSC Box Girder Bridges Considering Friction Coefficient and Material Strength (마찰계수와 재료강도를 고려한 PSC 박스 거더교의 최적설계)

  • Kim, Ki Wook
    • Journal of Korean Society of Steel Construction
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    • v.18 no.2
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    • pp.181-189
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    • 2006
  • This study analyzes the effects of the curvature friction coefficient, the wobble friction coefficient, and the increased strength of concrete, reinforced tendon on optimum de signs by using the optimum-design program, to minimize the cost of a PSC box girder bridge using the full staging method. The objective of this study is to find a proper tendon for the friction coefficient, and thereafter, to indicate the direction of the study development about tendons and to indicate the direction of a study on the increased strength of used materials. This program used the SUMT procedure and Kavlie's extended-penalty function to allow infeasible design points in the process. Powel's direct method was used in searching design points, and the gradient approximate method was used to reduce the design hours.

Optimum Design of PSC Box Girder Bridge considering the Influence of Unequal Span Length Division, Load Factor, and Variable Girder Depth (부등 경간 비율, 하중계수 및 변단면의 영향을 고려한 PSC 박스 거더교의 최적설계)

  • 박문호;김기욱
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.17 no.3
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    • pp.309-318
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    • 2004
  • This research automatically designed psc-box girder bridges by using an optimum design program and applied the results to the various types of bridges to verify if common facts used in steel bridges or concrete bridges can be applied to PSC bridges. Namely, it investigated appropriate unequal span length division by comparing with bridge of unequal and equal span length division, and verified the influence of the load factors which are changed by time or specification applying the results to various types of bridge. and it applied reinforced concrete bridge and steel bridge's variable girder depth which is slender and effective to save material costs to PSC box girder bridges. Technical solution of optimum design program used SUMT procedure, and Kavlie's extended penalty function to allow infeasible design points in the process. Powell's direct method was used for searching design points and a gradient's approximate method was used to reduce the design time.

Research on the Optimum Design for PSC Box Girder Bridges Using the Full Staging Method (FSM 공법 PSC 박스 거더교의 최적설계에 관한 연구)

  • Kim, Ki-Wook;Park, Moon-Ho;Chang, Chun-Ho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.8 no.3
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    • pp.159-167
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    • 2004
  • The objective of this study is development of the optimum design program to minimize the cost for PSC box girder bridge using the full staging method to indicate the necessity for the optimum design applied many types of bridges. It also considered the proper span length to girder depth ratio and the cell number along the width of bridge. This program used SUMT procedure and Kavlie's extended penalty function to allow infeasible design points in the process. Powell's direct method was used in searching design points and Gradient Approximate Method was used to reduce design hours. This study showed the convergence in design parameter and correlation of totally optimized cost according to cell numbers, span lengths, and lane numbers.

Optimum Design of Plane Steel Frame Structures Using Refined Plastic Hinge Analysis and SUMT (개선소성힌지해석과 SUMT를 이용한 평면 강골조의 연속최적설계)

  • Yun, Young Mook;Kang, Moon Myoung;Lee, Mal Suk
    • Journal of Korean Society of Steel Construction
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    • v.16 no.1
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    • pp.21-32
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    • 2004
  • In this study, a continuous optimum design model with its application program for plane steel frame structures developed. In the model, the sequential unconstrained minimization technique (SUMT) transforming the nonlinear optimization problem with multidesign variables and constraints into an unconstrained minimization problem and the refined plastic hinge analysis method as one of the most effective second-order inelastic analysis methods for steel frame structures were implemented. The total weight of a steel frame structure was taken as the objective function, and the AISC-LRFD code requirements for the local and member buckling, flexural strength, shear strength, axial strength and size of the cross-sectional shapes of members were used for the derivation of constraint equations. To verify the appropriateness of the present model, the optimum designs of serveral plane steel frame structures subject to vertical and horizontal loads were conducted.

Optimal Strengthening in RC Hollow Slab Bridges Using External Prestressing (외부 프리스트레싱을 이용한 RC 중공슬래브교의 최적보강)

  • Park, Kyung-Sik;Choi, Se-Hyu
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.13 no.6
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    • pp.204-211
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    • 2009
  • In this study, the optimal method is applied to strengthening of RC hollow slab bridges using external prestressing. The Queen-post and King-post shapes are considered to find the effective tendon configurations. In order to achieve the objective rating factor, the optimal configurations and tendon forces are obtained by using the Sequential Unconstrained Minimization Technique (SUMT). The object function for optimal strengthening is constituted with the dimensionless function of material costs. The constraints are formulated by design specification and the rating factor. The validity of this study is presented by the analysis of the results of strengthening of the RC hollow slab bridges.

Optimum Design of Braced Steel Framed Structures Considering Soil Condition Under Earthquake Loads (지반조건을 고려한 브레이스된 강골조 구조물의 내진 최적설계)

  • Park, Moon-Ho;Kim , Ki-Wook;Lee , Seung-Jo;Park , Jung-Hwal
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.10 no.4
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    • pp.97-107
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    • 2006
  • This study is structural analysis and continuous, discrete optimum design of braced steel frame structures under earthquake loads considering soil condition. The program which is able to perform simultaneously structural analysis and continuous, discrete optimum design, it is applied steel frame structures using unbraced, Z-braced, and X-braced types and analyze the program about static loads and seismic loads. The purpose of this study is to present proper braced type for seismic effects by comparing and analyzing results of analytic method about various cases using specially Newmark-Hall design spectrum, ATC design spectrum and ATC equivalent static analysis and finding minimum weight and design variables which satisfy the ultimate strength requirements of AISC-ASD specifications, the serviceability requirements and allowable story drift requirements of ATC-3-06 and various constraints.

The Study on the Placements of Brace Members Using Optimum Seismic Design of Steel Frames (강골조 구조물의 내진 최적설계에 의한 브레이스 부재 배치에 관한 연구)

  • Kim, Ki-Wook;Park, Moon-Ho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.9 no.1
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    • pp.111-119
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    • 2005
  • This study presents continuous and discrete optimum design algorithm and computer programs for unbraced and braced steel frame structures under earthquake loads. The program, which is avaliable to perform structural analysis and optimum design, continuous and discrete, simultaneously is developed. And the program adopts various braced types, Untraced, Z-braced(V), Z-braced(inverse-V), X-braced(A), X-braced(B), X-braced(C) and K-braced, in steel structures with static loads and seismic effects. The objectives in this optimization are to minimize the total weight of steel, and design variables, based on the ultimate strength requirements of AISC-ASD specifications, the serviceability requirements and allowable story drift requirements of ATC-3-06, and various constraints. The purpose is to present proper braced type for seismic effects by comparing and analysing results of various cases.

Optimum Design of LB-DECK Plate Girder Bridge (LB-DECK 플레이트 합성 거더교의 최적설계)

  • Kim, Ki-Wook;Park, Moon-Ho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.12 no.1
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    • pp.135-142
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    • 2008
  • This study is concerned with the optimum design of LB-Deck plate girder bridge. The optimizing problems of the composite bridge are formulated with objective functions and constraints. The objective functions are formulated as the total cost of the concrete deck and steel girder construction and the constraints are derived by criteria with respect to the Korean Highway bridge design. The optimizing algorithm using SUMT for optimum design of the Simple span, 2-Span, 3-span LB-deck plate and general RC-steel composite girder bridges (L=60m) which act live load(DB24). And their optimum numerical results are compares and analyzed to examine the possibility of optimization, the application and convergency of this optimizing algorithm.