• Composites Research
• /
• v.32 no.1
• /
• pp.29-36
• /
• 2019

The purpose of this paper is to suggest a lightweight design for the aluminum extrusion carbody structure of a double deck high-speed train using material substitution and size optimization method. In order to conduct material substitution, the topology optimization was used to determine the application parts of sandwich composites at the carbody structures. The results of analysis showed that sandwich composites could be applied at roof and 2nd underframe. The size optimization was used to determine thickness of the aluminum extruded and carbon/epoxy composite. The design variable, state constraint and objective function were formulated to solve the size optimization, and then, the feasible design was presented by these conditions. The results of the lightweight design showed that the weight of double deck high-speed train hybrid carbody could be reduced by 2.18(17.70%) tons.

• Journal of Korean Society of Steel Construction
• /
• v.12 no.5 s.48
• /
• pp.515-525
• /
• 2000

The purpose of this paper was to develop size & shape optimization programming algorithm of plane trusses. The optimum techniques applied in this study were extended penalty method of Sequential Unconstrained Minimization Techniques(SUMT) and direct search method with multi-variables proposed by Hooke & Jeeves. Upper mentioned two methods were used iteratively at each level of size and shape optimization routines. The design variables of size optimization were circular steel tube(structural member) diameter and thickness, those of shape optimization were joint coordinates, and the objective function was represented as total weight of truss. During the optimum design, two level procedures of size and shape optimization were interacted iteratively until the final optimum values were attained. At the previous studies about shape optimization of truss, the member sectional areas and coordinates were applied as design variables. So that they could not apply the buckling effect of compression member. In this paper, actual sizes of member and nodal coordinates are used as design variables to consider the buckling effect of compression member properly.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2001.11a
• /
• pp.167-172
• /
• 2001

구조최적화는 기계구조물의 동특성을 변경하기 위하여 필수적으로 수행되어야 할 요소이다. 어떠한 방법을 택하여 보다 효율적으로 수행할 것 인지가 엔지니어의 관심일 것이다. 구조최적화는 설계변수에 따라 치수최적화, 물성치최적화 형상최적화 등으로 나눌 수 있다. 형상 최적화는 구조물의 유한요소모델을 기본으로 경계의 형상이나 절점의 형상, 회전 등을 설계 변수로 삼는 것이다. 고유진동수를 높이거나 모드형상을 제어하기 위하여 평판에 보강재를 붙이는 경우가 있다. 이때 보강재의 위치나 치수 형상 등이 중요한 변수가 될 수 있다. 본 논문에서는 평판의 고유진동수를 극대화 하기위해 보 보강재를 붙이는 문제에서 보의 회전을 설계 변수로 삼아 최적설계를 수행 할 것이다.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.28 no.7
• /
• pp.1231-1237
• /
• 2022

In the present study, the optimization of the main particulars of a ship using AI-based design search techniques was investigated. For the design search techniques, the SHERPA algorithm by HEEDS was applied, and CFD analysis using STAR-CCM+ was applied for the calculation of resistance performance. Main particulars were automatically transformed by modifying the main particulars of the ship at the stage of preprocessing using JAVA script and Python. Small catamaran was chosen for the present study, and the main dimensions of the length, breadth, draft of demi-hull, and distance between demi-hulls were considered as design variables. Total resistance was considered as an objective function, and the range of displaced volume considering the arrangement of the outfitting system was chosen as the constraint. As a result, the changes in the individual design variables were within ±5%, and the total resistance of the optimized hull form was decreased by 11% compared with that of the existing hull form. Throughout the present study, the resistance performance of small catamaran could be improved by the optimization of the main dimensions without direct modification of the hull shape. In addition, the application of optimization using design search techniques is expected for the improvement in the resistance performance of a ship.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2012.05a
• /
• pp.403-407
• /
• 2012

The purpose of this study is to find the optimum skirt size for a composite pressure vessel using optimum analysis technique. The size optimization for skirt shape of a composite pressure vessel was conducted using sub-problem approximation method and batch processing codes programmed by APDL(ANSYS Parametric Design Language). The thickness and length of skirt part were selected as design variables for the optimum analysis. The objective function and constraints were chosen as weight and displacement of skirt part, respectively. The numerical results showed that the weight of skirt of a composite pressure vessel would be saved by maximum 4.38% through the size optimization analysis for the skirt shape.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.34 no.5
• /
• pp.567-573
• /
• 2010

In this study, we evaluated the structural integrity and weight of a rocket motor with a torispherical dome by size optimization. Size optimization was achieved by first-order and sub-problem methods, using the Ansys Parametric Design Language (APDL). For rapid design verification, a modified 2D axisymmetric finite-element model was used, and the bolt pre-tension load was expressed as function of the ratio of the cross-sectional area. The thickness of the dome and the cylindrical part of the rocket motor were selected as the design parameters. Our results showed that the weight and structural integrity of the rocket motor at the initial design stage could be determined more rapidly and accurately with the modified 2D axisymmetric finite-element model than with the 3D finite-element model; further, the weight of the rocket motor could be saved to maximum of 17.6% within safety limit.

• Pallet News
• /
• s.40
• /
• pp.36-45
• /
• 2006

한국파렛트풀(주)의 임직원을 대상으로 개발한 온라인 강좌 프로그램인 "파렛트와 유닛로드시스템 실무과정"의 일부분인 [컴퓨터를 이용한 유닛로드설계시스템:Vanning Management System]강좌의 VMS솔류션을 총 5회에 걸쳐 나누어 소개한다. 이 VMS소프트웨어는 Logen Solutions 라는 국내벤처기업이 개발한 제품으로서, Supply Chain상에서 발생하는 포장 및 적재 문제들 즉, 물류포장을 위한 제품 치수 및 포장 박스 치수 최적화와 일정한 용기내의 적재량 최적화 및 적재 패턴 최적화를 쉽고 빠르게 해법을 제공하는 종합 솔루션이다.

• Pallet News
• /
• s.38
• /
• pp.8-19
• /
• 2005

한국파렛트풀㈜의 임직원을 대상으로 개발한 온라인강좌 프로그램인 '파렛트와 유닛로드시스템 실무과정'의 일부분인 [컴퓨터를 이용한 유닛로드설계시스템: Vanning Management System] 강좌의 VMS 솔루션을 총 5회에 걸쳐 나누어 소개한다. 이 VMS 소프트웨어는 Logen solutions 라는 국내벤처기업이 개발한 제품으로서, Supply Chain상에서 발생하는 포장 및 적재 문제들 즉, 물류포장을 위한 제품 치수 및 포장 박스 치수 최적화와 일정한 용기내의 적재량 최적화 및 적재 패턴 최적화를 쉽고 빠르게 해법을 제공하는 종합솔루션이다.

• Pallet News
• /
• s.39
• /
• pp.20-32
• /
• 2005

한국파렛트풀(주)의 임직원을 대상으로 개발한 온라인 강좌 프로그램인 "파렛트와 유닛로드시스템 실무과정"의 일부분인 [컴퓨터를 이용한 유닛로드설계시스템:Vanning Management System]강좌의 VMS솔류션을 총 5회에 걸쳐 나누어 소개한다. 이 VMS소프트웨어는 Logen Solutions 라는 국내벤처기업이 개발한 제품으로서, Supply Chain상에서 발생하는 포장 및 적재 문제들 즉, 물류포장을 위한 제품 치수 및 포장 박스 치수 최적화와 일정한 용기내의 적재량 최적화 및 적재 패턴 최적화를 쉽고 빠르게 해법을 제공하는 종합 솔루션이다.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.8 no.2 s.21
• /
• pp.22-29
• /
• 2005

In this study we performed topology optimization and size optimization about support structure of pressure container which is installed in a Common Bed. The optimization study shows that structure weight optimization results can be applied to navy ship. The topology optimization is performed by static load, homogenization and optimality criteria method and size optimization is performed by SOL200 of NASTRAN.