• 대한기계학회논문집A
• /
• 제36권11호
• /
• pp.1361-1370
• /
• 2012

본 논문은 응력 등가정하중을 이용하여 금속제조공정에서 원하는 성형품과 단조품의 최종형상을 얻기 위한 형상최적화 방법을 제안한다. 성형품의 최종형상은 블랭크의 형상에 따라 달라지고 단조품의 최종형상은 빌렛의 형상에 따라 달라진다. 따라서 원하는 형상의 제품을 얻기 위해 구조최적화방법 중 형상최적화방법을 적용하였다. 금속성형 공정은 비선형 동적해석을 수행하므로 등가정하중법을 이용한다. 등가정하중법 중 가상모델을 이용한 응력 등가정하중은 등가정하중을 산출하는 새로운 방법으로 재료 특성의 가치를 재정의하여 응력 등가정하중을 계산한다. 본 논문에 포함된 예제를 통해 원하는 제품의 최종형상을 얻기 위한 최적의 블랭크 및 빌렛 형상을 도출하여 제안한 방법의 유용성을 검증한다.

• 한국구조물진단유지관리공학회 논문집
• /
• 제14권3호
• /
• pp.123-130
• /
• 2010

본 논문에서는 기존 건축물의 내진성능을 향상시키기 위해 시공성과 설치 비용적인 측면에서 상대적으로 우수한 강재댐퍼를 대상으로 기존 개발된 장치와 새로 개발된 형상의 장치에 대한 평가를 해석적으로 수행하였다. 해석결과는 강도 및 에너지 소산능력으로 평가하였으며, 제안된 내력 산정식의 적용을 아울러 평가하였다. 연구대상 댐퍼의 스트럿 형상은 V형, S형이며, 댐퍼의 스트럿 높이와 각도를 주요 변수로 한 후 ABAQUS를 이용하여 유한요소 해석하였다. 해석은 최대변위를 50mm로 하고 점진적인 이력변위곡선을 적용하여 수행하였다. 항복강도, 최대강도, 에너지 소산능력 평가결과, V형 및 S형 모두 우수한 성능을 보유한 것으로 평가되었으며, 또한 스트럿 각도 $60^{\circ}$ 및 높이 140, 200 mm의 성능이 안정적인 것으로 평가되었다. 전체적으로는 S형의 응답이 V형보다 안정적인 것으로 평가되어, S형 강재댐퍼의 적용성이 V형보다 유리한 것으로 평가되었다.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2001년도 추계학술대회 논문집
• /
• pp.85-88
• /
• 2001

Deep drawing process, one of sheet metal forming methods, is used widely. Circular or square shape blanks are currently studied mainly. Especially, circular blank for coating case of chip condenser remains bridges when it is made out of aluminum coil. The bridge reduces Material-withdrawal-rate of aluminum coil to $60\%$. This paper proposes a no-bridge blank instead of circular blank. To get the different values of two cases, comparison circular blank with no-bridge blank is accomplished in the point of thickness strain in the vicinity of flange. In order to find optimal condition in new proposed blank, several process variables - those are blank holder shape, die shape radii, punch shape radii and blank holding force - are changed.

• 소성∙가공
• /
• 제20권2호
• /
• pp.124-131
• /
• 2011

A flexible stretch forming process is useful for small quantity batch production because various shape changes of the flexible die can be achieved conveniently. In this study, the design variables, namely, the punch size, curvature radius and elastic pad thickness, were quantitatively evaluated to understand their influence on sheet formability using statistical methods such as the correlation and regression analyses. Forming simulations were designed and conducted by a three-way factorial design to obtain numerical values of a shape error. Linear relationships between the design variables and the shape error resulted from the Pearson correlation analysis. Subsequently, a regression analysis was also conducted between the design variables and the shape error. A regression equation was derived and used in the flexible die design stage to estimate the shape error.

• 한국자동차공학회논문집
• /
• 제2권2호
• /
• pp.33-41
• /
• 1994

The procedure to design the engine mount is briefly discussed and the optimum shape design process of engine mounting rubber using a parametric approach is suggested. An optimization code is developed to determine the shape to meet the stiffness requirements of engine mounts, coupled with the commercial nonlinear finite element program ABAQUS. A bush type engine mount used in a current passenger car is chosen for an application model. The shape from the result of the parameter optimization is determined as a final model with some modifications. The shape and stiffness of each optimization stage are shown and the stiffness of the optimized model along the principal direction is compared with the design specification of the current model. Finally, an overview of the current status and future works for the engine mount design are discussed.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2009년도 춘계학술대회 논문집
• /
• pp.256-259
• /
• 2009

In order to investigate the effect of strain states attributed to the lubrication during shape rolling, shape rolling for V-sectioned sheets was carried out with and without lubrication. The evolution of strain states during shape rolling was studied by three-dimensional finite element method (FEM). Shape rolling with and without lubrication produces shape-rolled samples in fairly similar outer shapes, since the distribution of normal strain components is nearly independent of the lubrication condition. In contrast, the distribution of shear strain components strongly depends on the lubrication condition.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2008년도 춘계학술대회 논문집
• /
• pp.349-352
• /
• 2008

In this study, a design method of developed shape for double-curved pressure vessel segment heads was proposed in consideration of in-plane strain induced by forming works. In order to obtain the developed shape of double-curved plate, at first, the segments are subdivided into elements and then they are stacked into a series of strips producing the outline of the approximately developed shape. The developed shape was determined by imposing the in-plane displacement obtained from forming analysis and regression analysis on the outline of the approximately developed shape. The validation of the proposed design method was verified by applying it to the actual products.

• 한국실내디자인학회논문집
• /
• 제20권6호
• /
• pp.228-235
• /
• 2011

The 卍 shape which is used as an aesthetical feature for traditional architecture can be seen in the stair railings of the house shaped ceramic potteries in the Eastern Han dynasty(A.D. 25-220) but with the introduction of Buddhism, it has been widely used for the decoration of the sarira(small crystals of the cremated monks) case. After the shape was seen in the Yungang and Dunhwang grottoes mural paintings, the use of it has been expanded. In Korea during the excavation of the Gyeongju Anapji which was the Eastern palace of the Shilla dynasty, a 卍 shaped wood which had been used as a handrail was found and this shape was also used in the railings of the Shilsangsa Baekjangarn temple stone pagoda and lantern and in the sarira case excavated in the Songrimsa temple stone pagoda. In Japan, the Nara period(A.D. 710-794) when there were many cultural exchanges with the Korean peninsula, the handrails of the 2ndfloor of the main hall of Hoyu-ji temple has a 卍 shape. This can be confirmed that this shape has been widely used as a design in Asian Buddhist architecture. Gilsangoonhae(吉祥雲海) which is the symbolic meaning of this shape means for long life and luck which had been used generally for the window designs of temples, palaces, and houses. In this study, it is giving the definition the beginning and the symbolic meaning of the 卍 shape which is being used from the ancient times until nowadays and the change of this shape used for window designs.

• 한국멀티미디어학회논문지
• /
• 제15권1호
• /
• pp.63-70
• /
• 2012

본 논문에서는 ASM(active shape model)의 성능을 향상시키기 위하여 형태(shape) 정렬 방법과 이차원 특징벡터 추출 방법을 제안한다. 기존 알고리즘은 입력 이미지의 중간 검출 랜드마크와 기준 모델 간의 정렬을 위하여 스케일, 회전, 이동 정보 만을 이용한다. 하지만 위의 평면적인 정보 만으로는 얼굴과 같이 입체적인 물체의 포즈 변화나 삼차원적인 움직임 등을 제대로 반영할 수 없다. 이를 개선하기 위하여 자유도를 증가시킴으로써 형태의 복잡한 변화에 보다 강인한 형태정렬 방식을 제안한다. 또한, 멀티스케일로 이차원 프로파일을 구하고 이들의 공분산 행렬을 trimming하여 검출속도를 향상시키는 방법을 제안한다. 비교적 다양한 포즈로 촬영한 얼굴 이미지 데이터베이스를 이용하여 제안 알고리즘의 형태 검출 성능을 확인한다.

• 동아시아식생활학회지
• /
• 제16권6호
• /
• pp.646-654
• /
• 2006

This study was designed to examine body shape control and its related factors, including BMI(body mass index), desire for weight control, satisfaction with body shape, dissatisfaction with specific parts of body shape, starting period of concern about body shape, as well as experience, method, result, counsel, effort, expense and knowledge of body shape control. The survey was completed by 180 female university students in Gyeongsanbukdo through a self-administered questionnaire during September and October of 2006. The subjects were assigned to one of three groups based on self-estimated figure: 47.8% of the students estimated their figure as 'normal', while 38.3% of the students estimated themselves as 'thin' and 13.9% of the students as 'fat'. The results were as fellows. The mean age of the subjects was $19.45{\pm}1.67$ with a height and weight of $161.15{\pm}4.99cm$ and $52.63{\pm}10.78\;kg$, respectively. Their self-estimated figure was significantly related to BMI, desire for weight control, satisfaction, dissatisfaction with a specific part, and experience, counsel and effort in body shape control. This research suggests that students need to know how to properly control body shape in health and beauty.