Study on the manufacturing process of precision linear guide rail through shape rolling and shape drawing

이상호,이상곤,김병민 대한기계학회 2010 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.24 No.8

Guide rails are one of the most important components in terms of equipment because the quality of the linear rail in-fluences on the precision linear motion. For long rails used in the guide rail, high dimensional accuracy as well as a cross-sectional shape is required. As a production method of guide rail, drawing process is mainly used. But, the shape rolling process is open used for the pre-process of the other metal forming process such as forging, extrusion, and shape drawing. The shape rolling process is one of the most effective processes which can make long products with constant irregular cross-sectional shape. Therefore, the tool shape is a very important process variable to obtain the required final product. The objective of this paper is the design of roll shape of the rolling process to produce the initial material with irregular cross sectional shape for shape drawing. Also, the die shape of the drawing process is determined to satisfy the dimensional accuracy of the final product. In this study, FE-analysis and artificial neural network (ANN) were applied to achieve the objective. Further, shape rolling and shape drawing experiments were performed to verify the result of FE-analysis. From results, it was possible to design the roll shape of shape rolling process effectively.

Shape recognition performance analysis and improvement in Sendzimir rolling mills

정철수,박정현,한성익,김종식 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.4

Twenty-high Sendzimir rolling mills (ZRMs) typically use small diameter work rolls to provide massive pass reduction. Because ofthe small diameter of the work rolls, a rolled steel strip has a complex shape mixed with quarter, edge, and center waves. When the stripshape is controlled automatically, actuator saturation occurs in the shape actuator such as AS-U rack. These problems affect productivityand the quality of products made from the rolled material. We analyzed problems on the shape control system of a ZRM. The shape recognitionperformance was analyzed by comparing the measured and recognized shapes by multi-layer perceptron (MLP) method. Inaddition, neural network using the radial basis function (RBF) method was proposed to improve the shape recognition performance of theshape control system in a ZRM. P-gain which compensates the scale of the strip shape is added to prevent actuator saturation. Finally, weverify the variation of actuator position using ZRM’s shape control simulator. Through simulation results, we found that shape recognitionperformance can be improved by the proposed method based on RBF neural network and actuator saturation problem can be improvedby increasing shape recognition performance.

여성용 셔츠칼라 형태 및 이미지의 실제와 3D 시뮬레이션 비교 연구 - DC Suite 5.0 Program을 중심으로 -

차수정 한국기초조형학회 2016 기초조형학연구 Vol.17 No.3

본 연구는 다양한 여성용 셔츠칼라 제도법에 대해 알아보고, 실제 제작된 의복과 3D 시뮬레이션 의복의 칼라 형태 및 이미지를 비교해 봄으로써 그 차이를 알아보고자 하였다. 셔츠칼라 형태는 같은 제도법에 따라 제도하였음에도 불구하고 실제와 3D 패턴 상에서 약간의 차이를 나타냈다. 칼라사이각도와 칼라사이길이는 대체로 비례하여 칼라사이각도가 작은 때 칼라사이길이도 짧게 나타났으나 3D 패턴에서는 반드시 적용되지 않아 차이를 보였다. 또한 칼라내측각도와 칼라외측각도에서도 차이를 나타냈다. 실제와 3D 시뮬레이션 실험의의 칼라에 대한 이미지를 평가한 결과, 실제는 깔끔한, 우아한, 멋있는, 세련된, 여성스러운, 감각 있는, 시원스러운, 매력 있는, 개성 있는, 날카로운 이미지가 높게 나타났으며, 3D 시뮬레이션 실험의의 경우에는 자유분방한, 부드러운 이미지가 조금 더 강한 것으로 나타나 차이를 보였다. 실제 실험의 칼라에서는 세련되고 여성스러우며 감각적인 오피스룩에 어울리는 이미지를, 3D 시뮬레이션 칼라에서는 자유롭고 부드러운 타운웨어나 리조트웨어에 어울리는 칼라의 이미지를 느낄 수 있었다. 실제 칼라의 이미지를 평가한 결과, 전문적이고 지적이며 깔끔하고 현대적인 이미지를 표현해야 하는 수트나 오피스룩의 칼라는 A1, A6 제도법을, 현대적이면서 날카로운 이미지를 표현하고자 하는 패셔너블한 룩의 칼라는 A4, A2 제도법을, 발랄하고 편안한 느낌이 필요한 리조트나 타운웨어의 칼라로는 A3, A7 제도법을 응용한다면 효과적일 것으로 생각된다. 본 연구는 실제 의복과 3D 시뮬레이션 의복에서 느껴지는 이미지와 패턴의 차이를 알아봄으로써 3D 시뮬레이션 의복의 실용화를 위해 보안되어야 할 점에 대해서 알아보고 패턴제도법에 따른 이미지와 형태의 차이를 파악할 수 있었다는 점에서 유용한 정보를 제공할 수 있을 것으로 생각된다. This research is to look into various women’s shirts collar drafting methods and to recognize the difference by comparing shape of collars of clothes made in real and 3D simulated images. Despite the same drafting method, collar shape had some differences of real and 3D patterns. In case of 2D pattern the angle of collar point to point was proportioned the length of collar point to point. If the angle of collar point to point was small, the length of collar point to point was same. But 3D pattern didn't have to be applied so 2D pattern and 3D pattern had differences. The results of evaluation of real and 3D simulation collar images, real collar had highly images like neat, elegant, swank, refined, feminine, fashionable, racily, magnetic, unique, sharp and 3D simulation clothes had wild and soft image strongly. It could feel to be suitable for office look like a sophisticated, feminine and sensuous in real collar. In 3D simulation collar, it had a image of town wear and resort wear like wild and soft. The evaluation results of real collar image, the suit and office look collar of having professional, neat and modern images put to use the methods of A1 and A6. If you represent the collar of fashionable look of having modern and sharp images, you need to use methods of A4 and A2. In case of resort and town wear collars, if it use the methods of A3 and A7, it can express vivid and comfortable images. This study give a valuable information of putting to practical use 3D simulation clothes as presenting differences of images and pattern between real and 3D simulation.

아이형 현수클램프의 L-PBF 적층 제조를 위한 열 이력 시뮬레이션 및 서포트 기반 최적화

윤석철,박 영,신재호 대한전기학회 2024 전기학회논문지 Vol.73 No.2

This study performed thermal history simulation and strategy optimization for additive manufacturing of eye-shaped catenary clamps used in high-speed railway overhead lines. Instead of the conventional casting material CuAl10Fe2, SUS 316L material suitable for additive manufacturing and having good toughness was used. The thermal analysis simulation software for additive manufacturing was utilized to optimize the additive manufacturing strategy for the parts where heat diffusion was not sufficient. The optimized additive manufacturing strategy was verified by simulation while adding supports, and the accuracy of the simulation was confirmed by comparing the simulation results with the actual experimental results. The results of this study can provide useful guidelines for additive manufacturing of eye-shaped catenary clamps and can be applied to other parts with complex shapes.

Design of Roll Profile in Shape Rolling by 3D-EFA

이상진,이경훈,고대철,이상곤,김병민 한국정밀공학회 2015 International Journal of Precision Engineering and Vol.16 No.4

The design of roll profile in shape rolling is important as a key role in improving product quality, such as dimensional accuracy,ensuring defect-free property and good mechanical properties. In this study, the design method using three dimensional electric fieldanalysis (3D-EFA) is proposed to design intermediate roll profiles for the shape rolling. The shape of equi-potential lines asintermediate roll profiles could be generated between the initial shape and final shape by 3D-EFA. The intermediate roll profile foreach pass is selected among a numerous equi-potential lines, and the effectiveness of the selected roll profiles is verified by FEsimulation. The over- or under-filling area is calculated from the result of FE-simulation, another equi-potential line is selected tocompensate for the area of the error. The proposed method is applied to a shape like rear door hinge that is generally designed bythe trial and error method to show the applicability of this method for various shapes. The lab-scale experiment is carried out withplasticine, and the results are within the allowable tolerance of ±0.5 mm. Therefore, the proposed method can be widely used to designroll profiles for complex shapes thereby reducing the design time.

전자파 레이더 모의해석에 의한 다층 경계 콘크리트 철근 및 내부 공동형상 검출 특성

박석균(Park Seok Kyun) 대한토목학회 2006 대한토목학회논문집 A Vol.26 No.4A

다층경계를 갖는 콘크리트 내의 철근 위치와 공동(공극) 형상을 효과적으로 검출하기 위해, 본 연구에서는 다층경계를 갖는 철근 콘크리트의 레이더 응답 및 무근 콘크리트 내 공동의 형상추정이 가능한 전자파 레이더의 해석 알고리즘을 개발하는데 목표를 두고 있다. 이들 조건에서의 철근 및 공동형상을 검출 또는 추정하기 위해 레이더 모의해석 모텔은 다양한 경계조건과 공동형상을 갖는 철근 또는 무근 콘크리트에 대해 적용되었다. 그리고 레이더 모의해석 결과에 대한 출력신호(회장) 는 컨볼루션법에 의해 계산하여 나타내었다. 그 결과 본 모의해석 기법은 철근콘크리트의 다층경계와 콘크리트의 공동형상에 대한 레이더 응답해석에 활용이 가능할 것으로 판단된다. More than effectively judging the existence of reinforcing bars under multi boundary layers and void shapes in concrete, this study aims to develop the analysis algorithm of radar response on multi boundary layers in reinforced concrete and radar capable of estimation of the shape of specific voids in plain concrete. To detect or estimate reinforcing bars and void shapes in these conditions, the simulation analysis model of transmission and reflection wave of electromagnetic radar is used. This radar simulation model is carried out with reinforced or non reinforced concrete of various boundary conditions and void shapes. And, the output signals (images) of radar simulation results are calculated and represented by convolution method. As the results, it is clarified that this simulation analysis technique can be used to analyze radar response on multi boundary layers in reinforced concrete and void shapes in concrete.

Development of Voxel Based Machining Shape Simulator

Keiichi Shirase,Tomoyuki Kouno,Keiichi Nakamoto (사)한국CDE학회 2010 한국CAD/CAM학회 국제학술발표 논문집 Vol.2010 No.8

In this study, voxel model representation is applied for a geometric machining shape simulator. A voxel model generally requires a huge amount of memory for shape representation, therefore the multilayer Octree structure of voxels is utilized to reduce the memory usage and improve the accuracy for the complicated shape representation of three-dimensional objects. Based on actual tool paths, case studies of machining shape simulation were carried out to examine the relation between the Octree layer levels with calculation time and memory usage. Furthermore, the ability to simulate machining shapes for both 3-axis and 5-axis milling operation were verified.

성형 오차 예측 모델을 이용한 가변 성형 공정에서의 탄성 회복 보정

서영호(Y. H. Seo),강범수(B. S. Kang),김정(J. Kim) 한국소성·가공학회 2012 소성가공 : 한국소성가공학회지 Vol.21 No.8

The objective of this study is to compensate the elastic recovery in the flexible forming process using the predictive models. The target shape was limited to two-dimensional shape having only one curvature radius in the longitudinaldirection. In order to predict the shape error the regression and neural network models were established based on the finite element (FE) simulations. A series of simulations were conducted considering input variables such as the elastic pad thickness, the thickness of plate, and the objective curvature radius. Then, at sampling points in the longitudinal-direction, the shape errors between formed and objective shapes could be calculated from the FE simulations as an output variable. These shape errors were expressed to a representative error value by the root mean square error (RMSE). To obtain the correct objective shape the die shape was adjusted by the closed-loop using the neural network model since the neural network model shows a higher capability of estimating the shape error than the regression model. Finally the experimental result shows that the formed shape almost agreed with the objective shape.

원추형 패턴이 적용된 GaN-LED에서의 광 추출 효율 향상을 위한 전산모사

안대용,이삼녕,김근율,유영문 한국물리학회 2014 새물리 Vol.64 No.8

In this study, the light extraction efficiency of a GaN-light-emitting diode (LED) designed on a sapphire substrate was analyzed using an optical ray-tracing method. Truncated cone-shaped patterns (TCPs) on a sapphire substrate were applied to improve the light extraction efficiency. The shape of the optimized TCP was designed through simulation. As a result, the light extraction efficiency of a LED chip with a TCP applied was about twice that of the LED chip with no pattern. The light extraction efficiency was enhanced by increasing the density and decreasing the size of the pattern simultaneously, which mean that the higher the number of patterns per unit area, the better the light extraction efficiency. The improvement in the light extraction efficiency through the TCP was mostly due to the top surface because the light extraction efficiency of top surface was increased by more than 2.5 times. 기하 광학적 광선 추적 방법을 이용하여 사파이어 기판 위에 설계된 GaN-LED 구조에 대해 광 추출 효율을 분석해 보았다. 광 추출 효율을 높이고자 사파이어 기판 위쪽에 상측이 절단된 원추형 패턴을 적용하였다. 최적화된 원추형 패턴의 모양을 시뮬레이션을 통해 설계하고 그 효율을 분석한 결과 패턴이 없는 경우에 비해 광 추출 효율이 약 2배 가량 증가하였다. 또한 단위 면적당 패턴이 차지하는 밀도가 크고 동시에 패턴의 부피가 작을수록 효율이 증가함을 보였다. LED소자의 각 면에 따른 광 추출 효율 증가는 TCP (truncated cone-shape pattern)에 의해 윗면으로부터 크게 기인하고 있었다.

시뮬레이션형 애플리케이션을 활용한 쌓기나무 학습이 초등학생의 수학과 학업성취와 ARCS기반 교수매체동기에 미치는 영향

하은경(Ha, Eun Kyoung),이영주(Lee, Young Ju) 학습자중심교과교육학회 2014 학습자중심교과교육연구 Vol.14 No.1

본 연구의 목적은 쌓기나무 단원 수업에서 시뮬레이션형 애플리케이션의 사용이 학습자의 학업성취와 교수매체동기에 미치는 영향을 규명하고자 하였다. 초등학교 6학년 학생 54명을 대상으로 시뮬레이션형 애플리케이션을 사용한 실험집단과 쌓기 나무를 사용한 통제집단으로 나누어 실험연구를 실시하였다. 교수매체동기 하위요인(주의집중, 관련성, 자신감, 만족감)에 대한 학생들의 인식을 분석하기 위하여 실험집단과 통제집단의 학생 10명에게 개인 면담을 실시하였다. 학업성취 효과측정 결 과 집단 간 차이가 없어 시뮬레이션형 애플리케이션 사용 수업이 쌓기나무학습만큼의 효과가 있는 것으로 나타났고, 시뮬레이션형 애플리케이션이 쌓기나무 학습에서 쌓기나무를 대체, 보완할 매체로서 가능성을 보여주었다. 교수매체동기 효과 측정결 과에서는 특히 주의집중 요인과 만족감 요인에서 학습 동기에 긍정적인 영향을 미치는 것으로 밝혀졌다. 인터뷰 결과 애플리케이션은 주의집중하기 좋았고, 정리할 필요가 없으며 편리하여 학생들의 만족도가 높았던 것으로 밝혀졌다. The purpose of this study is to examine the effects of use of simulation type applications on elementary school students’ academic achievement and instruction materials motivation in building blocks classes. We divided 54 six graders into the two groups: simulation type applications group and building blocks group. In order to investigate the students’ awareness about sub-factors of instruction materials motivation(attention, relevance, confidence and satisfaction), 10 students were selected from both experimental and control groups and personal interview was performed. The results showed that there was no difference between the two groups and simulation type applications had the potential to complement or replace the building blocks. Our data analysis suggests that the use of simulation type applications had positive impacts on students’ motivations in terms of attention concentration and satisfaction. In the interviews, students expressed that they could be focused. Students were also satisfied with the use of applications because it was not noisy and convenient and there was no need to clean up.