• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.5
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• pp.798-806
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• 2003

Structural optimization has been carried out in continuous or discrete design space. Methods for continuous design have been well developed though they are finding the local optima. On the contrary, the existing methods for discrete design are extremely expensive in computational cost or not robust. In this research, an algorithm using tabu search is developed fur the discrete structural designs. The tabu list and the neighbor function of the Tabu concepts are introduced to the algorithm. It defines the number of steps, the maximum number for random searches and the stop criteria. A tabu search is known as the heuristic approach while genetic algorithm and simulated annealing algorithm are attributed to the stochastic approach. It is shown that an algorithm using the tabu search with random moves has an advantage of discrete design. Furthermore, the suggested method finds the reliable optimum for the discrete design problems. The existing tabu search methods are reviewed. Subsequently, the suggested method is explained. The mathematical problems and structural design problems are investigated to show the validity of the proposed method. The results of the structural designs are compared with those from a genetic algorithm and an orthogonal array design.

• 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.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.10a
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• pp.171-178
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• 2004

The purpose of optimum design for structures is to minimize the cost and to obtain the reasonable structural systems. This design algorithm have many objective functions including discrete variables as sections, weight, stiffness and shapes. Simulated annealing, Genetic algorithm and TABU algorithm are used search for these optimum values in the structural design. TABU algorithm is applied to many types structures to search for section and distribution optimization and compared with the results of Genetic algorithm for evaluating the efficiency of this algorithm. In this paper, the plane truss of 10 elements and the space truss of 25 element having 10 nodes, star dome and cable dome are analyzed as analytical models.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1994.04a
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• pp.38-45
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• 1994

The general conceptual constitution of structural optimization is formulated. The algorithm using the gradient projection method and design sensitivity analysis is discussed. Examples of minimum-weight design for six-story steel plane frame are taken to illustrate the application of this algorithm. The advantages of this algorithm such as marginal cost and design sensitivity analysis as well as system analysis are explained.

• Journal of Ship and Ocean Technology
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• v.10 no.4
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• pp.24-33
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• 2006

So far, the generation of a hull structural analysis model, that is, a finite element model of a hull structure, has been manually performed by a designer using design experience, and thus has required lots of time because of many constraints, the complexity, and the huge size of the hull structure. To make this task automatic, an algorithm for generating the hull structural analysis model is developed using the seam information of the hull structure. A generating system of the hull structural analysis model is implemented based on the developed algorithm. The applicability of the developed algorithm is demonstrated by applying it to the generation of the global and hold structural analysis models of a deadweight 300,000 ton VLCC (Very Large Crude oil Carrier). The results show that the developed algorithm can quickly generate these models at the initial design stage.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.10a
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• pp.115-122
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• 2003

A Metropolis genetic algorithm(MGA) is developed and applied for the structural design optimization. In MGA favorable features of Metropolis algorithm in simulated annealing(SA) are incorporated in simple genetic algorithm(SGA), so that the MGA alleviates the disadvantage of finding imprecise solution in SGA and time-consuming computation in SA. Performances of MGA are compared with those of conventional algorithms such as Holland's SGA, Krishnakumar's micro genetic algorithm(μGA), and Kirkpatrick's SA. Typical numerical examples are used to evaluate the favorable features and applicability of MGA From the theoretical evaluation and numerical experience, it is concluded that the proposed MGA is a reliable and efficient tool for structural design optimization.

• Geomechanics and Engineering
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• v.20 no.6
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• pp.527-536
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• 2020

The paper represents an optimization algorithm for reinforced concrete retaining wall design. The proposed method, called Rao-3 optimization algorithm, is a recently developed algorithm. The total weight of the steel and concrete, which are used for constructing the retaining wall, were chosen as the objective function. Building Code Requirements for Structural Concrete (ACI 318-05) and Rankine's theory for lateral earth pressure were considered for structural and geotechnical design, respectively. Number of the design variables are 12. Eight of those express the geometrical dimensions of the wall and four of those express the steel reinforcement of the wall. The safety against overturning, sliding and bearing capacity failure were regarded as the geotechnical constraints. The safety against bending and shear failure, minimum and maximum areas of reinforcement, development lengths of steel reinforcement were regarded as structural constraints. The performance of proposed algorithm was evaluated with two design examples.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.205-210
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• 2000

An optimum design algorithm of PSC box girder bridges using design sensitivity analysis is proposed in this paper. For the efficiency of the proposed algorithm, approximated reanalysis techniques using design sensitivity analysis are introduced. And also to save the numerical efforts, an efficient reanalysis technique through approximated structural responses is proposed. A design sensitivity analysis of structural response is executed by automatic differentiation(AD). The efficiency and robustness of the proposed algorithm, compared with conventional algorithm, is successfully demonstrated in the numerical example.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.3 s.168
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• pp.146-153
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• 2005

In this paper, a multi-step optimization using genetic algorithm with variable penalty function is introduced to the structural design optimization of a grinding machine. The design problem, in this study, is to find out the optimum configuration and dimensions of structural members which minimize the static compliance, the dynamic compliance, and the weight of the machine structure simultaneously under several design constraints such as dimensional constraints, maximum deflection limit, safety criterion, and maximum vibration amplitude limit. The first step is shape optimization, in which the best structural configuration is found by getting rid of structural members that have no contributions to the design objectives from the given initial design configuration. The second and third steps are sizing optimization. The second design step gives a set of good design solutions having higher fitness for lightweight and minimum static compliance. Finally the best solution, which has minimum dynamic compliance and weight, is extracted from the good solution set. The proposed design optimization method was successfully applied to the structural design optimization of a grinding machine. After optimization, both static and dynamic compliances are reduced more than 58.4% compared with the initial design, which was designed empirically by experienced engineers. Moreover the weight of the optimized structure are also slightly reduced than before.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2000.04b
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• pp.466-473
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• 2000

Optimality Criteria algorithm based on the derivation of reciprocal approximations has been applied to structural optimization of large-scale structures. However, required computational cost for the serial analysis algorithm of large-scale structures consisting of a large number of degrees of freedom and members is too high to be adopted in the solution process of O.C. algorithm Thus, parallel version of O.C. algorithm on the network of personal computers is presented in this Paper. Parallelism in O.C. algorithm may be classified into two regions such as analysis and optimizer part As the first step of development of parallel algorithm, parallel structural analysis algorithm is developed and used in O.C. algorithm The algorithm is applied to optimal design of a 54-story plane frame structure