중심합성법에 의한 구조최적화에서 회귀함수변화의 영향

박정선(Jung-Sun Park),전용성(Yong-Sung Jeon),임종빈(Jong-Bin Im) 한국항공우주학회 2005 한국항공우주학회지 Vol.33 No.1

본 연구에서는 반응표면법에 다항함수, 지수함수, 로그함수등을 적용한 다양한 회귀함수를 이용하여 최적화를 수행하였다. 이를 검증하기 위해 트러스 구조와 하니콤 복합재 플랫폼에 대하여 응력 및 고유진동수를 고려하여 최적설계를 수행하였다. 근사함수를 효과적이고 용이하게 하는 방법을 실험계획법이라 하는데 중심합성법, 요인설계법, 회전계획법, 심플렉스법 등이 있으며, 본 연구에서는 중심합성법을 이용하여 반응표면을 생성하였다. 이를 위하여 구조해석 코드로 MSC/NASTRAN을 사용하였으며 최적설계 프로그램은 중심합성법을 기반으로 하여 다양한 회귀모델에 의한 반응표면을 적용하여 작성하였다. 또한 이 결과를 기존의 도함수를 이용한 최적화 기법이나 유전자알고리즘을 이용한 최적화 결과와 비교하여 반응표면법의 설계상의 장점 및 반응표면 생성 시 다양한 회귀모델에의 사용에 대한 신뢰성을 확인하였다. In this paper, the effect of various regression models is investigated on structural optimization using the central composite method. Three bar truss and the upper platform of a satellite are optimized using various regression models that are polynomial, exponential and log functions. Response surface method is non-gradient, semi-global, discrete and fast converging in optimization problem. Sampling points are extracted by the design of experiments using the central composite method. Response surface is generated using the various regression functions. Structural analysis for calculating constraints is executed to find static and dynamic responses. From this study, it is verified that the response surface method has advantage in optimum value and computation time in comparison to other optimization methods.

반응표면법을 이용한 RADIUS ROD의 경량화 설계

박소현(Sohyeon Park),양성모(Sungmo Yang),유효선(Hyosun Yu),김은성(Eunsung Kim),오상엽(Sangyeob Oh),김용관(YongKwan Kim) 한국자동차공학회 2012 한국자동차공학회 학술대회 및 전시회 Vol.2012 No.11

Recently, the automobile industry handles environmental standards and demands decrease of vehicle weight to reduce the environmental pollution. Reducing weight improves a car"s fuel economy. The weight of Aluminium Alloy used in this paper lights about 50~60% than the steel. And It have characterized that excel the stiffness, thermal resistance and corrosion resistance. The response surface method used in the paper is the statistical method. The RADIUS ROD used the lightweight material performs optimization method. Structural analysis usig the ANSYS program is executed to find static and dynamic responses. From this study, it is verified that the response surface method has advantage in optimum value and computation time in comparison to other optimization methods. By response surface method to derive the optimal design values, the analysis was performed again. The results of optimal design analysis, the weight reduces and intensity, frequency and deformation similar to existing products were able to see the analysis results.

반응표면법을 이용한 차체 부재의 충돌 성능 향상을 위한 설계 최적화

나승렬(Seungryul Na),허훈(Hoon Huh),송정한(Junghan Song) 한국자동차공학회 2004 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

Recently, the car industry is confront with various demands such as light weight and safety for a crash accident. But to achieve a light weight and safe car, design optimization is indispensable due to the many constraints in the auto-body. The response surface method is the statistical method which can be applied to the non-sensitivity base optimization. In this paper, this scheme is utilized to improve the crash performance of the front side member in auto-body with the response surface method and the commercial finite element program, LS-DYNA 3D. Total 27 design points are selected to construct the response surface. With these design points, the response surface about the absorbed energy and the mass are constructed and then are utilized to optimize the crash performance of the front side member. The crash performance and the deformation patterns are evaluated to confirm the crashworthness enhancement.

실험계획법과 반응표면법을 이용한 효율적인 신뢰도 기법의 개발

이상훈(S. H. Lee),곽병만(B. M. Kwak) 한국정밀공학회 2004 한국정밀공학회 학술발표대회 논문집 Vol.2004 No.10월

A reliability analysis and design procedure based on the design of experiment (DOE) is combined with the response surface method (RSM) for numerical efficiency. The procedure established is based on a 3<SUP>n</SUP> full factorial DOE for numerical quadrature using explicit formula of optimum levels and weights derived for general distributions. The full factorial moment method (FFMM) shows good performance in terms of accuracy and ability to treat non-normally distributed random variables. But, the FFMM becomes very inefficient because the number of function evaluation required increases exponentially as the number of random variables considered increases. To enhance the efficiency, the response surface moment method (RSMM) is proposed. In RSMM, experiments only with high probability are conducted and the rest of data are complemented by a quadratic response surface approximation without mixed terms. The response surface is updated by conducting experiments one by one until the value of failure probability is converged. It is calculated using the Pearson system and the four statistical moments obtained from the experimental data. A measure for checking the relative importance of an experimental point is proposed and named as influence index. During the update of response surface, mixed terms can be added into the formulation.

UV/TiO<SUB>2</SUB>/HAP 시스템에서 Sulfamethoxazole의 흡착과 광촉매반응에 대한 동역학적 및 통계적 해석

천석영(Chun, Suk-Young),장순웅(Chang, Soon-Woong) 한국지반환경공학회 2012 한국지반환경공학회논문집 Vol.13 No.5

항생제는 환경에 지속적인 노출과 저항성으로 인해 우려물질로 간주되고 있다. 항생제의 제한적인 생분해능에 따른 하수처리장에서의 불완전한 제거와 광범위한 사용으로 인해 상대적으로 많은 양이 환경에 방류되고 있는 실정이다. 이에 본 연구에서는 다양한 촉매(Titanium dioxide; TiO2, Hydroxyapatite; HAP)를 통해 항생제의 하나인 sulfamethoxazole의 동역학적 흡착과 광촉매반응에 대해 연구하였으며, 부가적으로 통계적 분석방법인 반응표면법(RSM)을 이용하여 UV/TiO2/HAP 시스템에서의 운전인자의 영향을 살펴보았다. 동역학적 연구결과로 TiO2/HAP의 흡착반응은 유사 2차 반응을 따르는 것으로 나타났으며, 입자내 확산 모델의 적용 결과, 반응속도 상수는 각각 TiO2=0.0641min<SUP>-1</SUP>, HAP=0.2866min<SUP>-1</SUP>와 TiO2/HAP=0.3708min<SUP>-1</SUP>으로 나타났다. RSM의 결과로는 ANOVA에서의 회귀항의 유의성이 나타났으며(P-value<0.05) 높은 결정계수 값(R<SUP>2</SUP>=96.2%, R<SUP>2</SUP>Adj=89.3%)이 나타나 이차 회귀모델의 예측이 만족스러운 것으로 관찰되었다. 그리고 Y(SMX 제거율, %)에 대해 예측된 최적 조건들은 코드화된 인자 기준으로 각각 x1(SMX의 초기농도)=-0.7828, x2(촉매의 양)=0.9974 그리고 x3(반응시간)=0.5738로 나타났다. 입자내 확산 모델과 광촉매 산화 반응의 결과에 따르면 TiO2/HAP 공정이 일반적인 고도산화공정에 비해 효율적인 것으로 관찰되었다. Antibiotics have been considered emerging compounds due to their continuous input and persistence in environment. Due to the limited biodegradability and widespread use of these antibiotics, an incomplete removal is attained in conventional wastewater treatment plants and relative large quantities are released into the environment. In this study, it was determined the adsorption and photocatalysis kinetics of antibiotics (Sulfamethoxazole, SMX) with various catalyst (Titanium dioxide; TiO2, Hydroxyapatite; HAP) conditions under UV/TiO2/HAP system. In addition, the statistical analysis of response surface methods (RSM) was used to determine the effects of operating parameters on UV/TiO2/HAP system. TiO2/HAP adsorbent were found to follow the pseudo second order reaction in the adsorption. In the result of applied intrapaticle diffusion model, the constants of reaction rate were TiO2=0.0641min<SUP>-1</SUP>, HAP=0.2866min<SUP>-1</SUP> and TiO2/HAP=0.3708min<SUP>-1</SUP>, respectively.The result of RSM, term of regression analysis in analysis of variance (ANOVA) showed significantly p-value (p<0.05) and high coefficients for determination values(R<SUP>2</SUP>=96.2%, R<SUP>2</SUP>Adj=89.3%) that allowed satisfactory prediction of second order regression model. And the estimated optimal conditions for Y(Sulfamethoxazole removal efficiency, %) were x1(initial concentration of Sulfamethoxazole)=-0.7828, x2(amount of catalyst)=0.9974 and x3(reation time)=0.5738 by coded parameters, respectively. According to the result of intraparticle diffusion model and photocatalysis experiments, it was shown that the TiO2/HAP was more effective system than conventional AOPs(advanced oxidation processes, UV/TiO2 system).

다양한 회귀모델을 이용한 구조 최적설계

전용성,박정선 한국항공대학교 항공우주산업기술연구소 2003 航空宇宙産業技術硏究所 硏究誌 Vol.13 No.-

Satellite upper platform is optimized by response surface method which has non-gradient, semi-glogal, discrete and fast convergency characteristics. Sampling points are extracted by design of experiments using Central Composite Method and Factorial Design. Response surface also is generated by the various regression functions. Structure analysis is execuated with regard to static and dynamic environment in launching stage. As a result response surface method is superior to other optimization method with respect to optimum value and cost of computation time. A confidence also is varified in the various regression models.

반응표면법을 활용한 복합재 팬 블레이드의 적층 각도 최적 설계

성윤주(YoonJu Sung),전용운(YongUn Jun),박정선(Jungsun Park) 한국항공우주학회 2019 한국항공우주학회 학술발표회 논문집 Vol.2019 No.4

반응표면법을 이용한 이중분사 막냉각 홀 최적화 연구

조문영(Moon-Young Cho),조이슬(Yi-Seul Cho),김윤제(Youn-Jea Kim) 대한기계학회 2014 대한기계학회 춘추학술대회 Vol.2014 No.11

In this study, the configurations and arrangement of DJFC (Double Jet Film Cooling) holes were optimized by using the surface response method. As the design parameters, the lateral compound angles(β1, β2=14˚~ 18˚) and the area ratios of lower and upper cooing holes(A1/A2=0.75~1.33) were considered, when the total area values of cooling holes were kept being constant. Numerical analysis was performed by using ANSYS CFX 14.5 with SST (Shear Stress Transport) turbulent model. The optimum configuration was chosen and relevant mechanisms for the enhanced cooling performance were elucidated by investigations of flow and cooling characteristics. The film cooling effectiveness distributions of representative cases were graphically depicted with various geometrical configurations.

반응표면법을 이용한 리니어모터 이송테이블의 형상 최적화

황영국(Young-Kug Hwang),은인웅(In-Ung Eun),이춘만(Choon-Man Lee) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.6

Linear motors are efficient mechanism that offers high speed and positioning accuracy. By eliminating mechanical transmission mechanisms, much higher speeds and greater acceleration can be achieved without backlash or excessive friction. However, an important disadvantage of linear motor system is its high power loss and heating up of motor and neighboring machine components on operation. Therefore, it is necessary to design moving table and cooling device with high stiffness, efficiency and light weight construction in designing stage of linear motors. In this paper, shape optimal design of linear motor moving table is performed to find best moving table shape by using response surface method. ANSYS and MINITAB were used as the optimizer. The results show that the optimum design results is better than those of the initial design.

반응표면법을 이용한 양항력형 수직축 풍력발전기 블레이드의 구조 최적 설계

소기성(Ki-Sung So),최찬웅(Chan-Woong Choi),이동철(Dong-Chul Lee),강기원(Ki-Weon Kang) 대한기계학회 2013 大韓機械學會論文集A Vol.37 No.11

본 논문에서는 반응표면법을 이용하여 양항력형 수직축 풍력발전기 블레이드의 구조 최적설계를 수행하였다. 선행연구의 구조해석 결과를 살펴보면 양항력형 수직축 풍력발전기 블레이드가 항복강도 이상의 응력이 발생하였으므로, 구조적 안전성을 확보하고자 최적화 기법을 적용한 구조설계를 재수행하였다. 이를 위해 먼저 블레이드에 발생하는 응력에 큰 영향을 주는 설계인자를 선정하였다. 이에 실험계획법 기반 반응표면법을 적용하였다. 목적함수 및 제한조건은 각각 중량 및 허용응력으로 설정하였다. 또한 중량 및 응력에 대한 설계인자의 영향을 평가하기 위한 민감도 해석을 수행하였다. 이러한 과정을 통해 양항력형 수직축 풍력발전기 블레이드의 구조 최적 설계를 수행하였다. This study deals with the structural optimization of hybrid vertical-axis wind turbine blades using a response surface method (RSM). The structural analysis results suggest that the stress of hybrid vertical-axis wind turbine blades exceeds the yield strength. Optimization techniques are then applied to structural design to ensure a safe structure. First, the design factors that strongly influence the structural response are identified. The RSM was applied based on the design of experiments. The objective function and constraint terms set the weight and allowable stress, respectively. Furthermore, sensitivity analysis was conducted to indicate the effects of the design factors on the stress and weight. Finally, structural design was performed for the hybrid vertical-axis wind turbine blade.