• 한국기계가공학회지
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• 제21권4호
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• pp.100-106
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• 2022

Topology optimization is applied for the optimal design of various products to ensure weight reduction and productivity improvement. Reducing the weight of the mold while maintaining its rigidity can ensure shortening of the production cycle, stabilization of the mold temperature, and reduction of mold material costs. In this study, a topology optimization technique was applied to the optimal design of the injection mold, and a topology-optimized model of the mold was obtained. First, the injection mold for the square specimens was modeled. Subsequently, a structural analysis was performed by implementing a load condition generated during the injection molding process. Topology optimization was performed based on the structural analysis results, and the models of the initial and topology-optimized designs were manufactured at 1/4 magnification using a 3D printer. Consequently, compared with the existing model, the weight of the topology-optimized model decreased by 9.8%, and the manufacturing time decreased by 7.61%.

• Advances in aircraft and spacecraft science
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• 제7권5호
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• pp.441-458
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• 2020

Rectangular-to-Ellipse Shape Transition (REST) inlets are a class of inward turning inlets designed for hypersonic flight. The aerodynamic design of REST inlets involves very complex flows and shock-wave patterns. These inlets are used in highly integrated propulsive systems. Often the design of these inlets may require many geometrical constraints at different cross-section. In present work a design approach for hypersonic inward-turning inlets, adapted for REST inlets, is coupled with a multi-objective optimization procedure. The automated procedure iterates on the parametric representation and on the numerical solution of a base flow from which the REST inlet is generated by using streamline tracing and shape transition algorithms. The typical design problem of optimizing the total pressure recovery and mass flow capture of the inlet is solved by the proposed procedure. The accuracy of the optimal solutions found is discussed and the performances of the designed REST inlets are investigated by means of fully 3-D Euler and 3-D RANS analyses.

• 항공우주기술
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• 제3권2호
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• pp.248-255
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• 2004

본 논문에서는 반응면 기법(response surface method)과 2차원 Navier-Stokes 방정식 해법을 이용하여 에어포일을 설계하였다. 수치 실험점들은 D-optimal 방법을 기반으로 선정하였으며 반응면 함수는 JMP를 이용하여 2차의 함수로 구성하였다. 설계기법의 검증은 NACA 64621 에어포일을 기저로 하여 Bell 에어포일의 공력특성을 갖도록 역설계하여 수행하였다. 설계기법은 스마트 무인기의 장기체공 능력을 위한 에어포일과 무인기용 로터에 적합한 저 Reynolds 에어포일 설계에 적용하였으며 제약조건을 만족하는 우수한 공력특성의 에어포일을 획득할 수 있었다.

• 소성∙가공
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• 제31권5호
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• pp.302-308
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• 2022

In this study, the weight of the platen was reduced using the structural strength analysis and topology optimization design of the extruder by finite element analysis. The main components of the extruder such as the stem and billet, were modeled, and the maximum stress and safety factor were verified through structural strength analysis. Based on the results of the structural strength analysis, the optimal phase that satisfies the limitation given to the design area of the structure and maximizes or minimizes the objective function was obtained through a numerical method. The platen was redesigned with a phase-optimal shape, the weight was reduced by 40% (from the initial weight of 11.1 tons to 6.6 tons), and the maximum stress was 147.49 MPa safety factor of 1.86.

• 대한조선학회논문집
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• 제59권6호
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• pp.413-422
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• 2022

Blast Hardened Bulkheads (BHB) are used to suppress damage propagation by internal explosions to reduce ships'vulnerability. However, for this reason, the weight of the ship inevitably increased, and other functions such as the ships'mobility were bound to deteriorate. Therefore, it is essential in the initial design of the ship to optimize the dimensions of the bulkhead to minimize the weight while decreasing the vulnerability of the ship. Research on design optimization of BHB has been conducted, but it has not considered explosive load in various hit scenarios. This study proposed an optimal design method for the curtain plate type blast hardened bulkhead, which is currently frequently applied by the Korean Navy in consideration of various hit scenarios. Using genetic algorithms, multiobjective design optimizations that minimize weight increase as well as minimize damage to ships were obtained. By optimizing the dimensions of the BHB considering various hit scenarios, the ship's vulnerability was improved while maintaining its mobility due to weight reduction.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집C
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• pp.580-585
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• 2001

A response surface method(RSM) is utilized for structural optimization and implemented on a parametric CAD platform. Once an approximation of the performance function is made, no formal design sensitivity analysis is necessary. The approximation gives the designer the sensitivity information and furthermore intuition on the performance functions. The scheme for the design of experiment chosen for the RSM has a large influence on the accuracy of converged solutions and the amount of computation. The D-optimal design criterion as implemented in this paper is found efficient for the structural optimization. The program is developed on a parametric CAD platform and tested using several shape design problems of such as a torque arm and a belt clip. It is observed that the RSM used provides a faster convergence than other approximation methods for design sensitivity.

• 한국자동차공학회논문집
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• 제20권5호
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• pp.145-151
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• 2012

New design of catalytic converter is proposed by optimization of DFSS (Design For Six Sigma) and DOE (Design Of Experiment) method which is based on taguchi matrix. As a result of the optimization of design of catalytic converter, this paper classifies Exhaust-downpipe shapes with 3 parameters to increase flow velocity uniformity of front catalytic substrate face from CFD results. after finishing with L9 Taguchi test matrix, it can be found the main effect of each design parameter of concept model, and optimal design level. in conclusion, it can be increase flow uniformity from 0.60 upto 0.80 with optimal diffuser shape for Turbo-charger.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표대회 논문집(III)
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• pp.712-717
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• 1998

Represtressed preflex beams do not allow tensile stress under service load by introducing additional prestressing at the lower concrete of beams. In this study, optimal design of represetressed preflex beams are numerically investigated. Design variables are dimension of plate girder. Object function is the total weight of plate girder. Constraints of the stress of plate girder and upper and lower concrete flange and lower and upper bounds on the design variables are imposed. Structural analysis is performed by D.A.R.P.(Design and Analysis of Represtressed Preflex beams). For numerical optimization, ADS(Garret N. Vanderplaats) program is used. From result of application examples, optimum designs of different cases are successfully obtained. The design program developed in this study seems efficient and robust for the optimization of represtressed preflex beams.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.1391-1392
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• 2013

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 추계학술대회 논문집
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• pp.779-780
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• 2010