• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1047-1053
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• 2009

This paper examined an applicability of optimum algorithm to develope an electric railway pole foundation automated design system. Based on the optimization theory that considered subgrade and bearing capacity characteristics, decided an optimum section of electric railway pole foundation. In this research, Optimum algorithm used the feasible direction method in structural analysis and design efficiently. Design variables are considered geometric properties and anchor bolt area of the electric railway pole foundation as optimum construction cost. Constraints are considered settlement., overturning and activity of foundation. And, also composed flexural and shearing strength. According to optimum analysis result., optimization theory is available more economical design comparing with railway pole foundation that is constructed by current standard drawing, and applicability verified in automated design system development.

• Journal of Korean Society of Steel Construction
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• v.12 no.5 s.48
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• pp.475-485
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• 2000

In this study, an automated optimum design program for steel box girder bridges has been developed for the optimum design of composite steel box girder bridges. The design constraints required for the optimum design of steel box girder bridges are based on the Korean standard bridge specification. Considering characteristics of steel box girder bridges, several approximation techniques, such as artificial constraint deletion, variable linking and stress reanalysis technique etc. are also introduced to enhance the efficiency of optimization. The developed program is mainly composed of major sub-system modules including structural analysis module using commercial structural analysis program such as RM-SPACEFRAME, optimum design module, pre-process module for friendly user input, and post-processor module for office automation. In addition, in order to demonstrate the efficiency and applicability of the developed optimum design program for steel box girder bridges, a few numerical examples are applied. Based on the results of the application, it may be stated that the automatic optimum design program developed in this study can be a prototype model for the developement of optimum design program for other type of bridge.

• Journal of Korean Association for Spatial Structures
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• v.1 no.1 s.1
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• pp.143-155
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• 2001

Generally, truss design has been determined by the designer's experience and intuition. But if we perform the most economical structural design we must consider not only cross-sections of members but also configurations(howe, warren and pratt types etc.) of single truss as the number of panel and truss height. The purpose of this study is to develope automated optimum design techniques for steel truss structures considering cross-sections of members and shape of trusses simultaneously. As the results, it could be possible to find easily the optimum solutions subject to design conditions at the preliminary structural design stage of the steel truss structures. In this study, the objective function is expressed as the whole member weight of trusses, and the applied constraints are as stresses, slenderness ratio, local buckling, deflection, member cross-sectional dimensions and truss height etc. The automated optimum design algorithm of this study is divided into three-level procedures. The first level on member cross-sectional optimization is performed by the sequential unconstrained minimization technique(SUMT) using dynamic programming method. And the second level about truss height optimization is applied for obtaining the optimum truss height by three-equal interval search method. The last level of optimization is applied for obtaining the optimum panel number of truss by integer programming method. The algorithm of multi-level optimization programming technique proposed in this study is more helpful for the economical design of plane trusses as well as space trusses.

• Computers and Concrete
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• v.10 no.2
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• pp.149-171
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• 2012

The problem of a concrete cross section under flexural and axial loading is indeterminate due to the existence of more unknowns than equations. Among the infinite solutions, it is possible to find the optimum, which is that of minimum reinforcement that satisfies certain design constraints (section ductility, minimum reinforcement area, etc.). This article proposes the automation of the optimum reinforcement calculation under any combination of flexural and axial loading. The procedure has been implemented in a program code that is attached in the Appendix. Conventional-strength or high-strength concrete may be chosen, minimum reinforcement area may be considered (it being possible to choose between the standards ACI 318 or Eurocode 2), and the neutral axis depth may be constrained in order to guarantee a certain sectional ductility. Some numerical examples are presented, drawing comparisons between the results obtained by ACI 318, EC 2 and the conventional method.

• Computers and Concrete
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• v.17 no.6
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• pp.761-786
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• 2016

This paper proposes an automated procedure for optimum seismic design of reinforced concrete (RC) frame structures. This procedure combines a smart pre-processing using a Tree Classification Method (TCM) and a nonlinear optimization technique. First, the TCM automatically creates sections database and assigns sections to structural members. Subsequently, a real valued model of Particle Swarm Optimization (PSO) algorithm is employed in solving the optimization problem. Numerical examples on design optimization of three low- to high-rise RC frame structures under earthquake loads are presented with and without considering strong column-weak beam (SCWB) constraint. Results demonstrate the effectiveness of the TCMin seismic design optimization of the structures.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.7
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• pp.152-157
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• 2014

Pro-program function of Pro/E has been utilized to expedite the design process of bellows. Design parameters selected for bellows design are manipulated to obtain the shapes user specified. User-oriented function may automate the bellows design process and this function may enable to reduce the design time remarkably. Generated bellows solid model has been applied to study of design sensitivity and optimum design. Among the selected design parameters, thickness of bellows affects system response most. Control-ring installed bellows may reduce the stress and prove to be an effective element for heavy load. The finite element analysis results combined with 3D model generated by pro-program may provide the feasible design directions to the bellows designer.

• Journal of the Society of Naval Architects of Korea
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• v.50 no.1
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• pp.59-68
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• 2013

Nowadays, optimum structural design techniques based on CSR have been developed and applied to the preliminary design stage focused on minimum weight and minimum construction cost of ship structure. Optimum structural design algorithm developed before could minimize weight and cost on fixed compartment arrangement. However, to develop more efficient design technique, a designer needs to combine optimized compartment arrangement with optimized ship structural design because compartment arrangement has a large effect on structural design according to the change of still water bending moment as a consequence of compartment arrangement change. In this study, automated algorithm for compartment arrangement of an oil tanker is developed to apply preliminary structural design. The usefulness of developed algorithm is verified with Aframax oil tanker constructed by STX shipbuilding Co.Ltd..

• Journal of the Korean Operations Research and Management Science Society
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• v.13 no.2
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• pp.34-46
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• 1988

This paper deals with design problem of unit load automated storage/retrieval systems (AS/RS). We propose an optimal design model in which the investment and maintenance costs of AS/RS, operating under dual command model is minimized over a time horizon satisfying the warehouse dimensional constraints. The model is formulated as an integer nonlinear program and an algorithm is proposed to find an optimum solution. The valididty of the solution algorithm is illustrated through an example.

• 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.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.2 s.173
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• pp.319-328
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• 2000

This paper presents a new design method of the 1 generation wheel bearing unit using a numerical optimization technique in order to increase bearing fatigue life. For calculating the fatigue life, a method of load analysis is studied on the automotive wheel bearing system. The design variables selected are ball size, initial contact angle, number of balls, pitch diameter, pre-load, and distance between ball centers. The method of feasible directions in ADS (Automated Design Synthesis) is utilized to automatically find the optimum design variables. To validate the design method, a computer program is developed and applied to a practical passenger car model. The optimum design results demonstrated the effectiveness of the proposed design method showing that the system life of the optimally designed wheel bearing unit is enhanced in comparison with that of the initial ones within the given available design space.