2차원 박판성형공정 해석을 위한 강소성 외연적 유한요소 수식화

안동규,정동원,정완진,An, Dong-Gyu,Jeong, Dong-Won,Jeong, Wan-Jin 대한기계학회 1996 大韓機械學會論文集A Vol.20 No.1

The explicit scheme for finite element analysis of sheet metal forming problems has been widely used for providing practical solutions since it improves the convergency problem, memory size and computational time especially for the case of complicated geometry and large element number. The explicit schemes in general use are based on the elastic-plastic modeling of material requiring large computataion time. In the present work, a basic formulation for rigid-plastic explicit finite element analysis of plain strain sheet metal forming problems has been proposed. The effect of some basic parameters involved in the dynamic analysis has been studied in detail. Thus, the effective ranges of parameters have been proposed for numerical simultion by the rigid-plastic explicit finite element method. A direct trial-and-error method is introduced to treat contact and friction. In computation, sheet material is assumed to possess normal anisotropy and rigid-plastic workhardening characteristics. In order to show the validity and effectiveness of the proposed explicit scheme, computations are carried out for cylindrical punch stretching and the computational results are compared with those by the implicit scheme as well as with a commercial code. The proposed rigid-plastic exlicit finite element method can be used as a robust and efficient computational method for analysis of sheet metal forming.

고출력 CW Nd:YAG 레이저를 이용한 인코넬 718 판재 절단시 모서리부 절단 특성 분석

안동규,변경원,Ahn, Dong-Gyu,Byun, Kyung-Won 대한용접접합학회 2008 대한용접·접합학회지 Vol.26 No.5

The objective of this paper is to investigate the effects of the laser power, the material thickness, comer angles, and the loop size on the formation of the comer in the cutting of Inconel 718 super-alloy sheet using high-power CW Nd: YAG laser. In order to investigate the influence of comer angles and loop sizes on the melted area and the formation of comer in the sharp comer, angular cutting tests and loop cutting tests were carried out. The results of the angular cutting tests were shown that the melted area is minimized and the melting mode is changed from nose melting in the thickness direction to the secondary melting induced by the attached dross when the comer angle is $90^{\circ}$. Through the results of loop cutting tests, the variation of the melted area and the comer shape in the sharp comer according to the loop size were examined. In addition, it was shown that a proper loop size is approximately 3 mm. The results of above experiments will be reflected on the knowledge base to generate optimal cutting path of the laser.

고출력 CW Nd:YAG 레이저를 이용한 저탄소 냉연강판 절단시 모서리부 절단 특성 분석

안동규,유영태,Ahn, Dong-Gyu,Yoo, Young-Tae 대한용접접합학회 2006 대한용접·접합학회지 Vol.24 No.4

The objective of present research works is to investigate the effects of process parameters, including the power of laser, cutting speed, material thickness, and the edge angle, on the melted area in the sharp edge of the cut material fur the case of cutting of a low carbon steel sheet using high-power CW Nd:YAG laser. In order to investigate the influence of edge angle and size of loop on the melted area in the sharp edge, angular cutting tests and loop cutting tests have been carried out. From the results of angular cutting tests, the relationship between the edge angle and the melted area has been obtained. The results of the experiments have been shown that the melted area is rapidly reduced from $120^{\circ}$ of the edge angle and the melted area is nearly zero at $150^{\circ}$ of the edge angle. Through the results of loop cutting experiments, the relationship between the cutting angle on the melted area in the edge according to the size of loop have been obtained. In addition, it has been shown that a proper size of loop is nearly 3 mm as the corner angle is greater than $90^{\circ}$ and 5 mm as the comer angle is less than $90^{\circ}$. The results of above experiments will be reflected on the knowledge base to generate optimal cutting path of the laser.

대형 PDP TV 후방 판넬 금형 개발에 관한 연구

안동규(Dong-Gyu Ahn),김진석(Jin-Suck Kim),문경제(Gyoung-Jae Moon),한길영(Gil-Young Han),문현수(Hyun-Su. Moon),윤영석(Young-Seok Yoon) 한국생산제조학회 2006 한국공작기계학회 춘계학술대회논문집 Vol.2006 No.-

The objective of this research works is to develop back panel dies of PDP TV with a large size. In order to design the geometry of the dies and an initial size of blank optimally, the finite element analysis has been carried out using AUTOFORM V4.2. The conner radius of the upper trimming area and the distance from the outer line of the blank holder to the outer line of the blank have been selected as design parameters to remove the wrinkling of the trimming area. The results of the analyses have been shown that a feasible product without wrinkles and skid lines can be obtained when the conner radius ranges from 6㎜ to 8㎜ and the distance is greater than 20㎜. From the proposed design of the dies and an initial blank size, the final die set of the back panel has been successfully manufactured.

Mold Flow를 이용한 박벽 케이스 제작용 사출성형 금형 설계

안동규(Dong-Gyu Ahn),김대원(Dae-Won Kim),박상오(Sang-Oh Park) 한국기계가공학회 2007 한국기계가공학회 춘추계학술대회 논문집 Vol.2007 No.-

The objective of this research work is to design the injection mould for thin walled parts and to investigate the influence of process parameters on the quality of the molded part using the Mold Flow. The type of the runner and gate is selected as a design parameter of the mould. The injection time, the injection pressure, the temperature of the injection material, and the cooling time are selected as process parameters to obtain an optimum injection condition. From the result of the analysis for each design condition of the mould, it has been shown that an insufficient filling does not occur when the mixed type of the runner system with a hot runner and a cold runner is introduced. In addition, the nozzle type of the hot runner and the optimum design of the cold runner have been found. The effects of process parameters on the shrinkage rate of the molding part has been performed using the result of analysis for each combination of process parameters.

투자 및 육성지원이 지역내총생산에 미치는 영향에 관한 빅 데이터 실증분석

안동규 ( Dong-gyu An ),신충호 ( Choong-ho Shin ) 산업진흥원 2020 산업진흥연구 Vol.5 No.3

본 연구는 빅데이터를 활용하여 투자 및 육성지원이 지역내총생산에 미치는 영향력을 다중회귀분석을 이용하여 분석하였다. 지역내총생산(GRDP)은 각 지역의 생산규모·지출수준·소득수준·산업구조 등을 집약적으로 내포하고 있는 지수로써, 지역경제 분석 및 국가의 정책수립에 활용하는 중요한 자료이다. 국가의 주요 국정과제를 올바르게 수행하기 위해서는 지역경제를 정확히 파악하는 것이 선행되어야 하는데, 이로 인해 최근 지역내총생산에 대한 관심이 급격히 증가하고 있다. 특히 해외투자는 투자유치국의 경제에 미치는 영향력이 상당하여, 이에 대한 많은 실증분석이 이루어지고 있다. 본 연구에서는 해외투자 및 국내육성지원이 지역내총생산에 미치는 영향력을 상관분석과 다중회귀분석을 실시하였으며, 그 결과 전체적으로 투자와 지원이 지역내총생산에 긍정적인 영향을 미친다는 결론을 도출하였다. This study analyzed the influence of investment and fostering support on gross regional product by utilizing big data using multiple regression analysis. Gross regional product (GRDP) is an index that intensively contains the production scale, expenditure level, income level, and industrial structure of each region, and is an important data used for regional economic analysis and national policy establishment. In order to properly carry out the country's major national tasks, it is necessary to accurately grasp the regional economy, and as a result, interest in regional gross domestic product is rapidly increasing. In particular, foreign investment has a significant impact on the economy of the host country, and many empirical analyzes are being conducted. In this study, correlation analysis and multiple regression analysis were conducted to examine the influence of foreign investment and domestic development support on gross regional product, and as a result, it was concluded that investment and support as a whole had a positive effect on gross regional product.

초등학교(初等學校) 한자교육(漢字敎育)의 방향(方向)에 대한 요구(要求) 분석(分析)

안동규 ( Dong Gyu An ) 한국한자한문교육학회 2010 漢字 漢文敎育 Vol.24 No.-

유한요소해석을 이용한 SPFC 780 판재의 충격 특성 연구

안동규(Dong-Gyu Ahn),남경흠(Gyeong-Heum Nam),한길영(Gil-Young Han),성대용(Dae-Yong Seong),양동열(Dong-Yol Yang),임지호(Jiho Lim) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.11

The objective of this paper is to investigate the influence of impact conditions on the impact characteristics of the SPFC 780 sheet for the case of the free boundary conditions. In order to examine impact characteristics of the sheet, three-dimensional finite element analyses have been performed. High speed tensile tests have been carried out to obtain strain-stress relationships including the effects of the strain rate. Through the comparison of the results of FE analyses and that of impact tests, an accurate FE model has been developed. In order to reduce error range of load and displacement, the hyper-elastic model and the damping factor have been employed. From the results of FE analyses, the variation of stress and strain energy in the SPFC 780 sheet has been quantitatively examined.

강원국제관광엑스포 외국인 인지도 분석

안동규(Ahn, Dong-Gyu),박성용(Park, Seong-Yong) 한국관광연구학회 2001 관광연구저널 Vol.- No.14

3 차원 사출성형 해석을 통한 냉장고 플라스틱 서랍 제작용 사출성형 금형의 형상적응형 냉각수로 설계

안동규(Dong Gyu Ahn),박민우(Min Woo Park),박승화(Seung Hwa Park),김형수(Hyung Su Kim) 대한기계학회 2010 大韓機械學會論文集A Vol.34 No.10

본 논문의 목적은 3 차원 사출성형해석을 통한 냉장고 플라스틱 서랍 제작용 사출성형 금형의 형상적응형 냉각수로 설계이다. 바람직한 형상적응형 냉각수로의 설계를 얻기 위하여 형상적응형 냉각수로의 직경과 위치가 사출성형 특성과 제품의 품질에 미치는 영향을 정량적으로 고찰하였다. 해석결과로부터 제품의 균일 냉각과 변형 최소화가 가능한 최적의 형상적응형 냉각수로의 설계를 도출할 수 있었다. 본 연구에서 제안된 사출성형 금형과 기존의 직선형 냉각수로의 사출성형 금형을 냉각/제품 제작 시간 및 제품 품질 측면에서 비교한 결과, 형상적응형 냉각수로를 가진 사출성형 금형이 제품의 생산성과 품질을 동시에 향상시킬 수 있음을 알 수 있었다. The objective of this study is to design the conformal cooling channels for the mould of a plastic drawer of a refrigerator by analysis of three-dimensional injection molding. In order to obtain the desired design of the conformal cooling channels, the influence of the diameter and the position of the conformal cooling channels on the moulding characteristics and the product qualities were quantitatively examined. From the results of the examination, an optimal design of the conformal cooling channels, which ensures uniform cooling and minimum potential deformation of the molded drawers, was estimated. By comparing the designed mould and a conventional mould with linear cooling channels from the viewpoints of the product qualities as well as cooling and cycle times, it was shown that the mould with conformal cooling channels can simultaneously improve the productivity of the injection moulding process and the product qualities.