• The Korean Journal of Rheology
• /
• v.4 no.1
• /
• pp.35-45
• /
• 1992

어미현상의 예측을 위하여 사각단면이 링을 환상압연하는 공정을 3차원 강소성 유 한요소법으로 해석하였다. 환상압연공정의 점진적이고 변형영역이 두롤 사이 근처로 국한되 므로 계산시간을 줄이기 위하여 두롤사이를 통과하는 부분만을 해석하였다. 변형도율의 분 포, 압연력, 구동롤의 토오크, 링과 롤 사이의 접촉면에서의 압력분포 및 변형된 링의 단면 모양을 계산하였다. 압연력, 구동롤의 토오크, 특히 변형된 링의 단면모양, 즉 어미현상은 계 산결과와 실험이 잘 일치하였다.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2004.06a
• /
• pp.89-94
• /
• 2004

Profile ring rolling process for large slewing rings of alley steels are developed. A profile ring with a round groove located asymmetrically on the outer surface is rolled. The process is simulated by the finite element method. The general-purpose commercial finite element analysis software, MSC.Superform, was used. Experiments are carried in the ring rolling machine and compared with the analysis.

• JOURNAL OF ELECTRICAL WORLD
• /
• no.7 s.91
• /
• pp.13-21
• /
• 1984

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.28 no.10
• /
• pp.1492-1499
• /
• 2004

In this paper, defect formation in ring rolling is revealed by computer simulation of ring rolling processes. The rigid-plastic finite element method is employed for this study. An analysis model having relatively fine mesh system near the roll gap is used for reducing the computational time and a scheme of minimizing the volume change is applied. The formation of the central cavity formation defect in ring rolling of a taper roller bearing outer race and the polygonal shape defect in ring rolling of a ball bearing outer race has been simulated. It has been seen that the results are qualitatively good with actual phenomena.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2013.05a
• /
• pp.1105-1106
• /
• 2013

• 제어로봇시스템학회:학술대회논문집
• /
• 1986.10a
• /
• pp.534-539
• /
• 1986

This paper considers the ring rolling process contorl and treats the problem of controlling the pressure roll and conical roll motion which critically affects final quality of the rolled products. Since the process dynamics reveals nonlinear characteristics and parameter uncertainty, an adaptive control scheme was applied. The results show that this proposed adaptive control scheme can produce rolled rings of closer dimensional tolerances as compared with nonadaptive control system.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2003.05a
• /
• pp.164-167
• /
• 2003

Profile ring rolling process is simulated by using the general purpose commercial finite element analysis software MSC.Superform Because the deforming region is restricted to the vicinity of the roll gap, only a ring segment spanning the roll gap is analysed in order to save computation time and cost. A profile ring with an external round groove is chosen as an example to be analysed. The rolls with and without groove were analysed to compare the amount of side spread. It is found that the grooves in the rolls reduce the amount of side spread.

• Transactions of Materials Processing
• /
• v.12 no.7
• /
• pp.631-639
• /
• 2003

Ring rolling process is simulated by using the general-purpose commercial finite element analysis software, MSC.Superform. Because the deforming region is restricted to the vicinity of the roll gap, only a ring segment spanning the roll gap is analyzed in order to save computation time and cost. First, a plain ring rolling of rectangular cross-section is simulated. Comparisons between computation and experiment show good agreement in the cross-sectional configuration of the deformed ring. Then, a profile ring with an external round groove is analyzed. The rolls with and without groove have been analyzed to compare the amount of side spread. It is found that the grooves in the rolls are effective in reducing the amount of side spread.

• Transactions of Materials Processing
• /
• v.24 no.3
• /
• pp.161-166
• /
• 2015

The finite element method has been widely used in the analysis of ring rolling. For ring rolling it requires a high computational expense due to the non-steady state material flow characteristics of the process. The high computational expense causes the finite element analysis to be impractical for industrial applications. In the current study, we aim to develop a practical implicit finite element modeling method for ring rolling. This method uses a step-wise steady state assumption and is called the “Stepped method”. The stepped method divides the whole process time of unsteady-state flow model into a finite number of steady-state models. It then solves the process at several specific time steps until convergence is reached. In order to confirm the performance and validity of the newly proposed stepped method, the result from the stepped method were compared to the results from a Lagrangian finite element method and to results from experiments reported in the literature.

• Journal of the Korean Society for Precision Engineering
• /
• v.10 no.2
• /
• pp.40-47
• /
• 1993

To diversify the area of application of UBET to the analysis of ring rolling which produces rings having more complex cross-sectional configuration, an element of triangular cross-section has been introduced and the corresponding kinematically admissible velocity field has been derived while considering the material flow between neighboring elements. The theoretical perdictions in roll torque and profile formation show good agreement with the experiments. The effect of process parameters such as feed rate and taper angle of the roll groove has been discussed.