• 한국산학기술학회논문지
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• 제16권2호
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• pp.952-962
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• 2015

열간 링 롤링 공법은 열간단조 후의 잠열을 이용하기 때문에 가공 부하가 적고 최종 환형제품에 가까운 제품을 제조하는 장점이 있다. 본 연구에서는 열간 링 롤링 공법에 의한 대형 직경의 환형 부품의 다중형상 링 제조를 목표로 AFDEX2D 및 AFDEX3D/HEXA/RING 시뮬레이터(simulator)를 이용하여 열간 단조공정부터 링 롤링 공정까지 연계된 공정을 유한요소 해석하였다. 또한 링 롤링공정의 유한요소해석 시간을 줄이기 위해 소성변형이 일어나고 있는 영역에서만 요소망을 조밀하게 재구성하는 이중요소 시스템을 적용하였다. 이 유한요소해석 결과를 바탕으로 실제 공정을 설계하고 실험하여 개발된 제품이 품질 규격을 만족하는지를 확인하였다. 또한 링 롤링 실험 완성품을 통하여 부품의 품질수준 및 공정능력을 평가하였다. 그 결과, 개발된 환형 부품은 40%의 투입재료 감소과 최종 제품의 원소재 회수율이 24% 증가하였다. 또한 링 롤링 제품은 내, 외경의 진원도가 0.5mm로 우수하였으며 공정능력 분석결과 외경 Cpk 1.49, 내경 Cpk 0.85를 확보하여 환형 부품의 다중 형상 열간 링 롤링 공정의 최적화를 실현하였다.

• 한국정밀공학회지
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• 제19권12호
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• pp.158-162
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• 2002

In this paper, the usefulness of a three-dimensional forging simulation technique is verified through its application to process design in rotor pole forging. A simulator, AFDEX3D developed based on the rigid-plastic finite element method and hexahedral elements, is employed. The simulated results of an application example found in a precision forging company are compared with the actually forged ones in detail. It has been verified that the simulation results are in good agreement with the actual phenomena.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 춘계학술대회 논문집
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• pp.252-255
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• 2008

We conduct finite element simulation of a cross-wedge rolling process using AFDEX 3D. The die is realistically modeled with emphasis on the hatched plicate over the slope or forming region. Coulomb frictional law is used to prevent slip between material and die. Constant shear frictional law is also investigated and it is esmphasized that the constant shear frictional law is improper for cross-wedge rolling simulation.

• 한국정밀공학회지
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• 제22권8호
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• pp.100-107
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• 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.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1487-1492
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• 2007

In this paper, we apply a forging simulator to automatic simulation of a connecting-rod forging process and compare its results with others found in the literature. The process information comes from the distributed examples of DEFORM3D. The process is fully automatically simulated using the tetrahedral element capability of AFDEX3D, developed by the authors. Our results are compared with the results found from the related literature, already simulated using DEFORM3D by other researchers. The comparison shows that our results are relatively excellent especially in terms of mesh quality on which the solution accuracy depends mainly.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 추계학술대회 논문집
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• pp.128-131
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• 2009

In this paper, three-dimensional finite element analysis of screw rolling process of a long shaft bolt is conducted by using a rigid-plastic finite element method based metal forming simulator AFDEX 3D. A whole sequence of cold forming processes of a long shaft bolt composed of forging and screw rolling processes is simulated to reveal the mechanism of screw formation. A mesh density control function is applied near the major plastic deformation region to achieve computational efficiency.

• 소성∙가공
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• 제19권4호
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• pp.248-252
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• 2010

In this paper, three-dimensional finite element analysis of thread rolling process of a 12 point flange head bolt is conducted using a rigid-plastic finite element method based metal forming simulator AFDEX 3D. A whole sequence of cold forming processes of a long shaft bolt composed of four forging stages and final thread rolling process is simulated to reveal the mechanism of thread formation. A mesh density control function is applied near the major plastic deformation region to achieve computational efficiency. It has been shown both numerically and experimentally that longitudinal lengthening or shortening is negligible in thread rolling.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 춘계학술대회 논문집
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• pp.437-440
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• 2009

In this paper, an aluminum ring forging process of manufacturing an optimized perform for a hot forging process is simulated using AFDEX 3D, a general-purpose metal forming simulator based on rigid-thermoviscoplastic finite element method. Non-isothermal analysis is carried out and the predictions are compared with the experiments in terms of dimensional accuracy. It was shown that the predictions are in good agreement with the experiments.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 추계학술대회 논문집
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• pp.183-188
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• 2007

We simulated a hot forging process for the spider with four legs and an enclosed die forging process for the spider with three legs using an intelligent forging simulator AFDEX 3D and compared the predictions with the experiments in terms of the deformed shape. The formation of characteristic lines was emphasized in the simulation to simulate the extruded legs with higher accuracy.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 춘계학술대회 논문집
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• pp.458-461
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• 2008

We carry out non-steady state finite element simulation of a porthole extrusion process for manufacturing a radiation pipe under isothermal assumption. It is assumed that welding takes place at the moment that the material contacts the plane of symmetry. Welding phenomena are revealed by observing the contacting mechanism of the material passed through the portholes. It is emphasized that mesh density control and intelligent remeshing during welding process govern the solution accuracy and the program applicability. AFDEX 3D is employed.