http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
허성찬(S. C. Heo),서영호(Y. H. Seo),박중원(J. W. Park),구태완(T. W. Ku),김정(J. Kim),강범수(B. S. Kang) 한국소성·가공학회 2008 소성가공 : 한국소성가공학회지 Vol.17 No.8
A flexible forming apparatus is composed a number of punches which have spherical pin tip shape instead of conventional solid die. The flexible forming tool consisted of punch array in a matrix form was proposed as an alternative forming method to substitute the conventional line heating method which use heat source to induce residual stress along specified heating lines. In this study, application of the flexible forming process to the small scale curved plate forming was conducted. Numerical simulations for both solid and flexible die forming process were carried out to compare the shape of the products between flexible and conventional die forming process. In addition, spring-back analysis was conducted to figure out the feasibility of the flexible forming process comparing with the die forming process in view of final configuration of the specimens. Moreover, experiment was also carried out to confirm the formability of the process. Consequently, it was confirmed that the flexible die forming method has capability and feasibility to manufacture the curved plates for shipbuilding.
다구치 방법을 이용한 해석 기반의 가변성형공정 변수 설계
허성찬(S. C. Heo),서영호(Y. H. Seo),구태완(T. W. Ku),송우진(W. J. Song),김정(J. Kim),강범수(B. S. Kang) 한국소성가공학회 2010 한국소성가공학회 학술대회 논문집 Vol.2010 No.10
In this study, case study based on the numerical simulations for evaluating the effects of the punch size and the properties of the elastic pads on the forming accuracy in the flexible forming process is carried out. Usually, elastic pads such as urethane material which has hyper-elastic properties are inserted between the steel plate and the flexible dies for smoothing the discrete forming surfaces that are formed by the combination of the forming punches. The punch size, the thickness and hardness of the pads are considered as three factors that mostly affect the forming accuracy in the flexible forming process. The Taguchi’s design of experiments method using an orthogonal array is utilized to investigate the effects of the factors. According to the Taguchi’s design method, nine simulation models organized by the orthogonal array table for the three factors with three levels are determined. Shape error norm-values with regard to an objective shape are calculated and analyzed for evaluating the forming accuracy. Consequently, it was found that the punch size is the most influential design variable, and the thickness and hardness of urethane pads should be carefully determined.
유한요소법을 이용한 가변 스트레치 성형공정의 적합성 검증
서영호(Y. H. Seo),허성찬(S. C. Heo),박중원(J. W. Park),송우진(W. J. Song),구태완(T. W. Ku),김정(J. Kim),강범수(B. S. Kang) 한국소성가공학회 2009 한국소성가공학회 학술대회 논문집 Vol.2009 No.10
This paper deals with a usefulness verification of stretch forming process using flexible die. The stretch forming method is widely used in aircraft and high-speed train industries for manufacturing of skin structure, which is made of sheet metal. A great number of solid dies are originally used and developed for specific shapes with respect to different curvature radii of the skin structures. Accordingly, flexible stretch forming process is proposed in this study. It replaces the conventional solid dies with a set of height adjustable discrete punches. A usefulness of the flexible die is verified through extensive numerical simulations of the stretch forming process for simply curved sheet plate. The elastic recovery in considered and formability evaluations are conducted through a comparison of symmetry plane configurations.