• 한국정밀공학회지
• /
• 제22권8호
• /
• pp.100-107
• /
• 2005

The objective of the study is to improve the quality of wheel bearing hub by the rigid-plastic finite element analysis and the response surface methodology. The rigid-plastic finite element codes, AFDEX-2D and DEFORM-3D, were used to analyze the two-dimensional and three-dimensional forging processes, respectively. The response surface analysis is used to find the minimum underfill by the variation of design variables such as the height of billet after upsetting and punch angles of blocker dies. The metal flow of forged product shows good agreement with the results from 2D and 3D analysis. Also, the quality of the wheel bearing hub has been improved by the optimization of design variables and the machining time has been reduced by the machining allowance.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2002년도 춘계학술대회 논문집
• /
• pp.620-623
• /
• 2002

Spinning has been used widely for the manufacture of hollow parts with rotational symmetry. With developing CNC machine, CNC machine center can be applied to the spinning processes. In this paper, a study on the development of CNC spinning technology without mandrel is carried out. The deforming process of the spinning process was simulated by DEFORM 3D to give basic design data.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2003년도 The 8th Asian Symposium on Precision Forging ASPF
• /
• pp.152-157
• /
• 2003

A typical die-set for enclosed-die forging of half axle gears in double action hydraulic press is presented, the important factors those influence on precision forming of half axle gears are analyzed, warm forming process of half axle gears is simulated by FEM software $DEFORM\_3D$. The results show, that proper die structure and dimension, suitable web thickness and position can improve material filling, ensure full filling of tooth cavity.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 1999년도 춘계학술대회논문집
• /
• pp.120-123
• /
• 1999

The precision cold forging process for steering yoke of automobile has been analysed by using rigid-plastic finite element analysis code DEFORM-3D Also the experiment has been performed through the optimized process. Until now steering yoke has been largely manufactured by hot forging or welding of forged head and shaft parts because of technical difficulty. the study has shown successful results of the precision cold forging through the proper selection of the process.

• 한국의류학회지
• /
• 제27권9_10호
• /
• pp.1015-1025
• /
• 2003

This paper proposes a method for constructing the virtual characters adopting the personal body types for the clothing coordination. At first, the method produces the 38 kinds of the Korean 3D body models considering sex, ages and body types, and constructs model DB. We select a model similar to the personal body size from DB and deform the selected model according to body size. The method deforms the model linearly for height 12 items, width 6 items, depth 5 items and round 13 items, and constructs the personal character fitted to the personal body size. The preprocess for model deformation consists of grouping for body part and establishing the feature points. Linear deformation for each group leads us to easy construction of the virtual personal characters. This method has two advantages as follows: 1. Large reduction of man power, cost and time for DB construction of the body 3D models, since the preprocess permits us to effectively use the various body models whose geometrical structures are different, 2 Suitability to Web-based clothing coordination, since the body deformation method is simple and its speed is very high.

• 한국기계가공학회지
• /
• 제17권5호
• /
• pp.117-122
• /
• 2018

3D printing technology and its applications have grown rapidly in academia and industry. We consider a 3D printing system designed for the selective laser sintering (SLS) method, which is one of the powder bed fusion (PBF) techniques to build up the final product by layering sintered powder slices. Thermal distortion of printing products is a critical challenge in 3D printing. This study investigates temperature-dependent conformational behaviors of 3D printed samples of sintered poly-ether-ether-ketone (PEEK) powders using molecular dynamics simulations. The wear and chemical resistance properties of PEEK are understood, as it is a well-known biocompatible material used for implants. However, studies on physical phenomena at nanoscale in PEEK are rarely published in public. We simulate dissipative particle dynamics to elucidate how a cavity regime forms in PEEK at different system temperatures. We demonstrate how PEEK structures deform subject to the system temperature distribution.

• 소성∙가공
• /
• 제16권8호
• /
• pp.575-581
• /
• 2007

The high dimensional accuracy of the cold forged part could be acquired by the accurate dimensional modification for the die, which is, the dimensional changes from the die through forged part to final part after heat treatment were considered. The experimental and FEM analysis are performed to investigate the dimensional changes from the die to final part on cold forged part, comparing with the machined gear. The dimension of forged part is compared with the die dimension at each stage, such as, machined die, cold forged part, and heat-treated-part. The elastic characteristics and thermal influences on forging stage are analyzed numerically by the $DEFORM-3D^{TM}$. The analyzed residual stress of forged part is considered into the FE-analysis for heat treatment using the $DEFORM-HT^{TM}$. The effects of residual stress affected into the dimensional changes could be investigated by the FEA. Each residual stress of gears was measured practically by laser beam type measurement.

• 소성∙가공
• /
• 제22권7호
• /
• pp.383-388
• /
• 2013

Metal flow of the beam blank during H-beam rolling was examined in order to correlate the rolling defects with the beam blank configuration. For this purpose, H-beam rolling was performed on the beam blank where stainless steel bolts were inserted as the marker at the web and flange. The positional variation of the marker was monitored at each rolling pass, and the result was compared with the 3D FEM simulation employing the point tracking function. The simulation results were reasonably agreed with the experimental within the error of 0.5~1mm on both web and flange of the H-beam. It is anticipated that the 3D FEM simulation employing the point tracking function provides the guidance information on analyzing the correlation between the rolling defects and the beam blank configuration in H-beam rolling.

• 한국멀티미디어학회논문지
• /
• 제16권1호
• /
• pp.108-118
• /
• 2013

최근 컴퓨터 비전, 컴퓨터 그래픽스 분야의 급속한 발전과 하드웨어의 우수한 성능으로 인해 3차원 모델링 기술 또한 급속히 발전 되었다. 그리고 다양한 3D 컨텐츠들의 등장으로 3차원 모델링 기술의 수요가 더욱 많아지고 그 질 또한 높아지고 있다. 3D 얼굴 모델은 이러한 컨텐츠들에 폭 넓게 적용될 수 있어 활용성이 높다. 본 논문에서는 주어진 한 장의 2D 정면 얼굴 영상으로부터 3D 얼굴을 모델링하는 방법을 제안한다. 이를 위해 다수의 정점으로 구성된 3D 일반 얼굴 모델을 입력 얼굴 영상과의 대응관계를 통해 변형하여 3D 얼굴을 모델링한다. 우선 AAM을 이용하여 입력된 얼굴 영상에서 특징점을 추출한다. 그리고 추출된 특징점만으로 직관적인 모델을 변형하기 위해 메쉬 워핑을 적용한다. 여기에 얼굴의 깊이 정보를 유도하기 위하여 한 장의 정면 얼굴 영상을 활용한 명도 변화 기반의 깊이 값의 추출을 시도한다. 이러한 과정을 통해 경제적으로 부담되지 않으며 사용 환경에 대한 제한이 적어 보편적으로 활용될 수 있는 3D 얼굴 모델링 방법을 구현하고 그 타당성을 실험으로 보인다.

• 대한기계학회논문집A
• /
• 제34권10호
• /
• pp.1543-1548
• /
• 2010

분말단조 공정은 정형의 자동차부품을 제작하는데 널리 이용되고 있다. 분말야금이란 금속 원료 분말을 사용하여 원하는 제품의 형태로 성형을 한 다음 적정온도에서 소결하여 필요한 금속 제품을 제조하는 기술을 말한다. 본 연구에서는 자동차 엔진의 경량화를 위한 피스톤 제작에 관한 것이다. 분말단조로 제작 되어진 엔진 피스톤의 특성을 유한요소해석을 통해서 알아보겠다. 유한요소해석은 DEFORM/3D 를 이용해서 성형성을 평가하도록 하겠다. 성형온도, 구배각도, 마찰계수의 변화에 따른 피스톤의 성형성을 알아보겠다.