프로세스 분할 병행에 의한 통합 구조설계 운용

황진하,박종회,Hwang, Jin-Ha,Park, Jong-Hoi 한국전산구조공학회 2008 한국전산구조공학회논문집 Vol.21 No.1

Distributed operation of overall structural design process, by which product optimization and process parallelization are simultaneously implemented, is presented in this paper. The database-interacted hybrid method, which selectively takes the accustomed procedure of the conventional method in the framework of the optimal design, is utilized here. The staged application of design constraints reduces the computational burden for large complex optimization problems. Two kinds of numeric and graphic processes are simultaneously implemented by concurrent engineering approach in the distributed environment of PC networks. The former is based on finite element optimization method and the latter is represented by AutoCAD using AutoLISP programming language. Numerical computation and database interaction on servers and graphic works on independent clients are communicated through message passing. The numerical experiments for some steel truss models show the validity and usability of the method. This study has sufficient adaptability and expandability, in that it is based on general methodologies and industry standard platforms. 본 연구는 제품(구조물)최적화와 프로세스 병렬화가 통시에 실행되는 통합구조설계운용 방법을 제시한다. 관행적 설계방법과 최적화설계방법의 장점들을 선택적으로 수용 보완하는 DB연동 혼성방법을 통해 설계조건을 단계적으로 적용함으로써 대형최적화문제의 계산적 부담 및 이질감을 최소화하였다. PC 네트워크상에서 공학설계를 구성하는 수치연산과 도면작성이 동시공학적 절차로 구현되고, 여기서 설계의 수치연산은 유한요소기반 최적화 방법에 기초하며, 그래픽작업은 AutoLISP 프로그래밍을 통하여 AutoCAD로 표현된다. 수치연산을 병행하는 서버 및 이산최적화를 지원하는 DB서버와 그래픽스테이션 간의 통신은 메시지패싱 방식으로 이루어진다. 표준최적화모델인 트러스구조에 대한 수치실험은 연구의 타당성과 유용성을 보여준다. 공학설계를 구성하는 주된 작업요소를 분산 병행 처리하는 된 연구는 일반적 방법론 및 산업표준환경 등에 기초한다는 점에서 충분한 적용성과 확장성을 갖는다.

정하중을 받는 구조물의 적층 제조를 위한 적응적 가중치 적용 동시 위상최적설계

조재훈(Jae Hun Jo),이중석(Joong Seok Lee) 대한기계학회 2021 大韓機械學會論文集A Vol.45 No.9

적층 제조는 전통적인 방식에서는 구현하기 어려운 복잡한 설계의 구조물을 효과적으로 제작할 수 있는 장점을 가지고 있다. 반면에 구조물 전체를 순차적으로 적층하여 제조하기 때문에 공간적으로 돌출되거나 떠있는 부분이 제조 과정에서 변형되거나 심지어 파괴되는 문제가 발생할 수 있다. 본 연구에서는 위상최적설계 기법을 이용하여 정하중을 받는 주 구조물과 적층 제조 과정에서 주 구조물의 자중을 떠받치는 역할을 하는 지지부를 동시에 설계한다. 위상최적설계 수식화에 있어 주 구조물과 지지부를 포함하는 전체 구조 간의 변형률에너지의 비를 목적함수 내의 다중 물리량의 상대적 중요도를 조절하는 적응적 가중치로 정의한다. 주 구조물과 지지부의 물성치를 정규화된 값으로 설정하여 다양한 설계 예제에 대하여 물성치의 변화에 따른 설계 결과에의 영향을 비교 분석한다. The additive manufacturing method has advantages for effectively manufacturing structures of complicated designs that are difficult to address by using traditional methods. Because the structure is built by sequential stacking entirely, however, the overhang or floating regions may be deformed or even fail during the additive manufacturing process. In this work, we design the main structure under a static load and the support parts for the main structure simultaneously using topology optimization for additive manufacturing. In the topology optimization formulation, the weighting factor determining the relative contribution of multiple quantities in the objective function is defined as a ratio of the strain energy of the main structure to that of the whole structure including support parts. By normalizing the material properties of the main structure and the support parts, the effects of the properties in the results are investigated for various design examples.

복합구조제어시스템의 동시최적설계

박관순,고현무 한국지진공학회 2002 한국지진공학회논문집 Vol.6 No.5

복합구조제어시스템의 동시최적설계방법에 관하여 연구하였다. 여기에서는 수동제어장치 뿐만 아니라 능동제어장치의 배치와 용량, 제어기 등이 설계변수가 되며 설계인자들의 만족도를 나타내는 선호도함수를 정의하여 이를 이용하여 최적화문제를 정식화한다. 또한 수동 및 능동제어장치의 설계변수로부터 동시에 최적해를 찾아내기 의한 수치적 방법으로 유전자알고리즘을 사용하였다. 지진하중을 받는 다자유도 구조물의 설계에 및 수치모사를 통하여 제안한 방법의 타당성을 검증하고자 하였다. In this paper, an integrated optimum design method for hybrid structural control system is studied. Not only the distribution and the capacity of passive devices but also those of active devices, and the controllers are treated as design variables in the proposed approach. Multi-objective optimization problem is formulated by using the preference function, which is newly defined in this study. Genetic algorithm is adopted as a numerical searching technique in order to simultaneously find the optimum solutions. The validity of the proposed method is verified through the example designs and the numerical simulations of an earthquake excited multi-degrees-of-freedom structure.

로버스트 파라미터 설계에서 개선된 기대함수를 이용한 다특성 동시 최적화 방안

권용만(Yong Man Kwon),조장식(Jang Sik Cho),최승배(Seung Bae Choi) 한국자료분석학회 2004 Journal of the Korean Data Analysis Society Vol.6 No.1

다구찌 로버스트 파라미터 설계에서 직교배열표를 이용한 교차배열(product array)은 제어인자와 잡음인자의 모든 교호작용을 고려한 실험배치를 하여 실험수가 지나치게 많은 단점을 가지고 있다. 실험수를 줄일 수 있을 뿐 아니라 기존의 잘 정립된 실험계획법 이론을 이용한 대체방안으로 통합배열접근법(combined array approach)이 Welch 등(1990) 여러 학자에 의해 연구되었다. 이러한 연구들은 하나의 품질특성만을 고려하였다. 본 논문에서는 Derringer와 Suich(1980)가 제시한 기대함수를 개선하여 통합배열에 의한 실험배치에서 로버스트 파라미터 설계를 위한 다특성(multiple quality characteristics) 동시 최적화 방안을 제안한다. 하나의 사례를 들어 기존의 다구찌 방법론과 새로이 제안한 방법론을 비교 연구한다. In the Taguchi robust parameter design, the product-array approach using orthogonal arrays is mainly used. However, it often requires an excessive number of experiments. An alternative approach, which is called the combined-array approach, was suggested by Welch et. al. (1990) and studied by others. In these studies, only single quality characteristic was considered. In this paper we propose how to simultaneously optimize multiple quality characteristics using improved desirability function when we used the combined-array approach. An example is illustrated to show the difference between the Taguchi s product-array approach and the combined-array approach.

인자분석을 이용한 로버스트 파라미터 설계 동시 최적화 방안

권용만(Yong Man Kwon),조장식(Jang Sik Cho) 한국자료분석학회 2003 Journal of the Korean Data Analysis Society Vol.5 No.4

잡음인자(noise factor)는 품질변동의 요인이 되는데 로버스트 파라미터(robust parameter) 설계에서는 품질변동에 둔감한 제어인자(control factor)의 최적조건을 찾는 것이다. 본 논문에서는 다특성(multiple quality characteristics)인 경우 제어인자의 동시 최적화 조건을 찾는 방안으로 인자분석(factor analysis)에 의한 최적화 방안을 제시한다. 하나의 사례를 들어 제안한 방안과 기존의 방안을 비교 연구하였다. Robust parameter design is to identify appropriate settings of control factors that make the system s performance robust to changes in the noise factors that represent the source of variation. In this paper, we introduce a factor analysis approach to simultaneously optimize multiple quality characteristics in the robust parameter design. A real example is illustrated to compare our approach with already existing method.

자동미분을 이용한 민감도기반 분리시스템동시최적화기법의 개선

박창규,이종수,Park, Chang-Gyu,Lee, Jong-Su 대한기계학회 2001 大韓機械學會論文集A Vol.25 No.2

The paper describes the improvement on concurrent subspace optimization(CSSO) via automatic differentiation. CSSO is an efficient strategy to coupled multidisciplinary design optimization(MDO), wherein the original design problem is non-hierarchically decomposed into a set of smaller, more tractable subspaces. Key elements in CSSO are consisted of global sensitivity equation, subspace optimization, optimum sensitivity analysis, and coordination optimization problem that require frequent use of 1st order derivatives to obtain design sensitivity information. The current version of CSSO adopts automatic differentiation scheme to provide a robust sensitivity solution. Automatic differentiation has numerical effectiveness over finite difference schemes tat require the perturbed finite step size in design variable. ADIFOR(Automatic Differentiation In FORtran) is employed to evaluate sensitivities in the present work. The use of exact function derivatives facilitates to enhance the numerical accuracy during the iterative design process. The paper discusses how much the automatic differentiation based approach contributes design performance, compared with traditional all-in-one(non-decomposed) and finite difference based approaches.

동시최적화 설계기법을 이용한 항만용 크레인의 흔들림 제어계 설계

김영복(YOUNG-BOK KIM),문덕홍(DUK-HONG MOON),양주호(JOO-HO YANG),채규훈(GYU-HOON CHAE) 한국해양공학회 2005 韓國海洋工學會誌 Vol.19 No.3

The sway motion control problem of a container hanging on the trolley is considered in this paper. In the container crane control problem, the main issue involves suppressing the residual swing motion of the container at the end of acceleration, during deceleration, or for an unexpected disturbance input. For this problem, in general, many trolley motion control strategies are introduced and applied. In this paper, we introduce and synthesize a swing motion control system, in which a small auxiliary mass is installed on the spreader. In this control system, the actuator reacting against the auxiliary mass applies inertial control forces to the container to reduce the swing motion in the desired manner. In many studies, the controllers used to suppress the vibration have been synthesized for the given mathematical model of plants. In many cases, the designers have not been able to utilize the degree of freedom to adjust the structural parameters for the control object. To overcome this problem, so called "Structure/Control Simultaneous Method" is used. From this, in this paper the simultaneous design method is used to achieve optimal system performance. And the experimental result shows that the proposed control strategy is useful, to the case of that the controlled system is exposed to the uncertainties and, robust to disturbances like wind.

통합적 설계법을 이용한 크레인의 Anti-Sway 시스템 설계

김영복(Y. B. Kim),문덕홍(D. H. Moon),강귀봉(G. B. Kana),채규훈(G. H. Chae),안상백(S. B. Ahn) 한국동력기계공학회 2004 한국동력기계공학회 학술대회 논문집 Vol.- No.-

The swing motion control problem of a container hanging on the trolly is considered in the paper. In the container crane control problem, suppressing the residual swing motion of the container at the end of acceleration, deceleration or the case of that the unexpected disturbance input exists is main issue. For this problem, in general, many trolley motion control strategies are introduced and applied. In this paper, we introduce and synthesize a swing motion control system in which a small auxiliary mass is installed on the spreader made by ourselves. In this control system, the actuator reacting against the auxiliary mass applies inertial control forces to the container to reduce the swing motion in the desired manner. In many studies, the controllers used to suppress the vibration have been synthesized for the given mathematical model of plants. And, the designers have not been able to utilize the degree of freedom to adjust the structural parameters for the control object. To overcome this problem, so called □Structure/Control Simultaneous Method□is used. From this, in this paper, the simultaneous design method is used to achieve optimal system performance. And the experimental result shows that the proposed control strategy is useful to the case of that the controlled system is exposed to the uncertainties and, robust to the unexpected disturbance inputs.

항공기 날개 형상 최적화를 위한 distributed design의 적용

김태희(TaeHee Kim),최성임(Seongim Choi) 한국전산유체공학회 2013 한국전산유체공학회 학술대회논문집 Vol.2013 No.5

Aircraft design is very difficult because aircraft is composed of many subsystems which are highly coupled. Therefore, aircraft design with decoupled analysis at subsystems is meaningless and it is important to perform an integrated analysis. Designers revise existing design methods or find a new design method for satisfying the complex design requirement, one of them is a Multidisciplinary Design Optimization(MDO) which is methodology that tries to slove those issues and many study is performed recently. A distributed design divides the aircraft system into system and subspace levels and distributes independent role to each discipline. Collaborative Optimization(CO) and Concurrent Sub-Space Optimization(CSSO) are kinds of distributed design which have different formulations and different characteristics. CSSO carries out system analysis and solves a series of sensitivity equations. Also CSSO contains concept of responsible coefficient and trade-off coefficient. In contrast, CO doesn’t has system analysis and sensitivity equation and uses concept of auxiliary variables and compatibility condition. In current study, we compare Collaborative Optimization(CO) and Concurrent Sub-Space Optimization(CSSO) methods about their advantages and weaknesses through their application to aircraft wing shape design problem.

잡음인자를 포함한 실험설계에 관한 다중 반응 최적화

권용만 朝鮮大學校 統計硏究所 2006 統計硏究所論文誌 Vol.8 No.1

Although multiple responses are quite common in practical applications, the robust parameter design I frequently dealt with by considering only one response. In this paper, we propose how to simultaneously optimize multiple responses for robust design when data are collected from a combined array. The proposed method is based on the quadratic loss function. An example is illustrated to show the proposed method.