• 소성∙가공
• /
• 제8권2호
• /
• pp.152-159
• /
• 1999

This study is to investigate the effects of warm deep drawing with aluminum sheets of A1050-H16 and A5020-H32 for improving deep drawability. Experiments for producing circular cups and square cups were carried out for various working conditions, such as forming temperature and blank shapes. The limit drawing ratio(LDR) of 2.63 in warm deep drawing of circular cups in case of A5020-H32 sheet, whereas LDR of 2.25 in case of A1050-H16, could be obtained and the former was 1.4 times higher than the value at room temperature. The maximum relative drawing depth for square cups of A5020-H32 material was also about 1.92 times deeper than the depth drawn at room temperature. The effects of blank shape and forming temperature on drawability as well as thickness distribution of drawn cups were examined and discussed.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 1998년도 춘계학술대회논문집
• /
• pp.45-52
• /
• 1998

This study is to investigate the effects of warm deep drawing with aluminum sheets of A1050-H16 and A5052-H32 for improving deep drawability. Experiments for procucing circular cups and square cups were carried out for various working conditions, such as forming temperature and blank shape. The limit drawing ratio(LDR) of 2.63 in warm deep drawing of circular cups in case of A5052-H32 sheet, whereas LDR of A1050-H16 is 2.25, could be obtained and the former was 8 times higher than the value at room temperature. The maximum relative drawing depth for square cups of A5052-H32 material was also about 2 times deeper than the depth drawn at room temperature. The effects of blank shape, and temperature on drawability of aluminum materials as well as thickness distribution of drawn cups were examined and discussed.

• 소성∙가공
• /
• 제10권3호
• /
• pp.253-260
• /
• 2001

This study was performed to investigate the optimized warm forming conditions which gave the maximum drawing depth in square cup drawing of clad sheet metals, by changing the temperatures of die and blankholder and also shapes and materials of blanks. Two kinds of clad sheet metals, STS304-A1050-STS304 and STS304-A1050-STS430 were selected for experiments. The relative drawing depth of STS304-A1050-STS304 clad sheet was increased up to 4.4 at $150^{\circ}C$ that was 29% higher than at room temperature, whereas STS304-A1050-STS430 material was improved to 3.9 at $120^{\circ}C$ which was 15% better than at room temperature. In addition, comparison of wall thickness and hardness of a warm drawn cup with those of room temperature showed more even distributions. No separation between each laminated material after drawing occurred through inspection by microscope as well as application of penetrant test and bond strength test. Therefore, warm forming technique was confirmed to give better results in deep drawing of stainless clad sheet metal.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2002년도 금형가공 심포지엄
• /
• pp.136-143
• /
• 2002

Warm draw die technique which is one of the new forming technologies to improve formability of sheet metal is applied to the cylindrical and square cup drawing of stainless-aluminum clad sheets. In experiments the temperature of die and blank holder is varied from room temperature to $180^{\circ}C$, while the punch is cooled by circulation of coolant to increase the fracture strength of workpiece on the punch comer area. Test materials chosen for experiments are STS304-A1050-STS304 clad sheets. Teflon film as a lubricant is used on both sides of a workpiece. The limit drawing ratio and relative drawing depth as well as quality of drawn cups(distribution of thickness)are investigated and validity of warm drawing process is also discussed. No separation between each laminated material after drawing occurred through inspection by microscope as well as application of penetrant remover and bond strength test. Therefore, warm forming technique was confirmed to give better results in deep drawing of stainless clad sheet metal.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2001년도 춘계학술대회 논문집
• /
• pp.89-93
• /
• 2001

This study was carried out to investigate the warm deep drawability of square cups of clad sheet metals, by changing temperatures of die and blankholder and blank materials. Two kinds of clad sheet metals, STS304-A1050-STS304 and STS304-A1050-STS430 were chosen for experiments. The relative drawing depth of STS304-A1050-STS304 clad sheet was increased up to 4.4 at $150^{\circ}C$ that was $29\%$ higher than at room temperature, whereas STS304-A1050-STS430 material was improved to 3.65 at $120^{\circ}C$ which was $16\%$ better than at room temperature. In addition, comparison of wall thickness and hardness of a warm drawn cup with those of room temperature showed more even distributions. Therefore, warm forming technique was confirmed to ive better results in deep drawing of stainless clad sheet metal.

• Design & Manufacturing
• /
• 제14권1호
• /
• pp.22-29
• /
• 2020

The analysis was carried out using the press molding analysis program by applying six parameters such as material type change, material thickness, friction coefficient, r_p, r_d and blank holder pressure. As a result of CAE analysis of the soft material DC04 and the relatively hard material HX300LAD, the thickness of the punch R part of the soft material was significantly reduced. The flange portion is greatly increased in thickness in the hard material by the compression action. As a result of considering the deformation amount of 0.6mm, 1.0mm, 1.5mm according to the material thickness, the influence of the thickness is considered to be very small. In case of the material thickness of 0.6mm, the rate of change increases due to the deep drawing depth relative to the material thickness. The sizes of the punches R and die R have the greatest influence on the change in thickness of the material in drawing molding, the smaller the punch R, the thinner the edges of the product, The larger the R of the die, the greater the material thickness of the flange portion. As the coefficient of friction and the blank holder pressure increase, the frictional force of the flange portion increases, which increases the radial force in the drawing process and increases the thickness change of the flange portion.

• 보존과학회지
• /
• 제28권1호
• /
• pp.87-94
• /
• 2012

이 연구에서는 해운대 석각을 대상으로 3차원 레이저 스캐닝 시스템을 적용하여 디지털복원 및 표면심도 모델링을 수행하였다. 먼저 석각의 3차원 디지털복원은 광대역 및 정밀 스캐너를 이용하여 점군 데이터를 획득하였고, 정합, 병합, 필터링, 폴리곤 메쉬, 도면화 작업 순으로 진행하였다. 특히 정밀 스캐닝 폴리곤은 광대역 폴리곤에 비해 글자의 필획, 음각깊이 및 선명도 등이 매우 뛰어났다. 표면심도 모델링은 폴리곤 분리, 기준축 설정, 기준점 선정, 등고선도 맵핑 및 폴리곤 병합을 통해 완성하였으며, 사진과 폴리곤 이미지에 비해 글자의 상대적 음각깊이(5~17mm)와 윤곽이 매우 뚜렷하게 나타났다. 광대역 및 정밀 스캐닝을 병합한 디지털복원 기술을 통해 석각의 전체 형태와 미세형상을 신속하고 정확하게 복원하였고, 표면심도 모델링은 육안과 사진으로 불분명했던 부분을 가시적으로 표현해주었다. 앞으로 정기적인 모니터링을 통해 석각의 다양한 손상과 시간에 따른 주변 환경 변화를 수치적으로 분석할 수 있을 것으로 판단된다.

• 정보처리학회논문지:소프트웨어 및 데이터공학
• /
• 제2권12호
• /
• pp.899-902
• /
• 2013

본 논문에서는 두 개의 단백질 분자가 결합하여 복합체를 구성할 때, 두 분자 간의 접촉 영역을 발견하여 3차원 공간에서 가시화하는 방법을 제시한다. 두 분자 간의 접촉 영역은 기하학적인 측면에서 서로 상보성을 보이며, 상보적인 결합의 크기를 나타내기 위한 방법으로 접촉 영역의 면적을 계산하는 방법이 주로 사용되어 왔다. 접촉 영역의 면적을 수치화한 결과와 접촉 영역의 단순 표시는 서로 다른 접촉 영역에 대해 상대적인 결합 강도를 비교하기에는 적합하지만, 접촉 영역이 가진 기하학적인 특성을 분석하기에는 부적합하다. 본 논문에서는 접촉 영역에서 상보성을 표시하기 위해 상대 분자와의 거리 정보를 가시화하는 방법을 제시한다.

• 한국전산구조공학회논문집
• /
• 제37권3호
• /
• pp.173-178
• /
• 2024

본 논문에서는 스테레오 비전 센서를 이용한 프리팹 강구조물(PSS: Prefabricated Steel Structures)의 조립부 형상 품질 평가 기법을 소개한다. 스테레오 비전 센서를 통해 모형의 조립부 영상과 포인트 클라우드 데이터를 수집하였으며, 퍼지 기반 엣지 검출, 허프 변환 기반 원형의 볼트 홀 검출 등의 영상처리 알고리즘을 적용하여 조립부 영역의 볼트홀을 검출하였다. 영상 내 추출된 볼트홀 외곽선 위 세 점의 위치 정보에 대응되는 3차원 실세계 위치 정보를 깊이 영상으로부터 획득하였으며, 이를 기반으로 각 볼트홀의 3차원 중심 위치를 계산하였다. 통계적 기법 중 하나인 주성분 분석 알고리즘(PCA: Principal component analysis) 알고리즘을 적용함으로써 3차원 위치 정보를 대표하는 최적의 좌표축을 계산하였다. 이를 통해 센서의 설치 방향 및 위치에 따라 센서와 부재 간 평행이 아니더라도 안정적으로 볼트홀 간의 거리를 계측하도록 하였다. 각 볼트홀의 2차원 위치 정보를 기반으로 볼트홀의 순서를 정렬하였으며, 정렬된 볼트홀의 위치 정보를 바탕으로 인접한 볼트홀 간의 각 축의 거리 정보를 계산하여 조립부 볼트홀 위치 중심의 형상 품질을 분석하였다. 측정된 볼트홀 간의 거리 정보는 실제 도면의 거리 정보와의 절대오차와 상대오차를 계산하여 성능 비교를 진행하였으며, 중앙값 기준 1mm 내의 절대오차와 4% 이내의 상대오차의 계측 성능을 확인하였다.