환상압연공정에서 측면유동에 의한 어미현상(Fishtailing)의 예측에 관한 연구

김광희; 양동열

Korean Journal of Rheology, Vol.4, No.1, 35-45, June, 1992

Export Citation

환상압연공정에서 측면유동에 의한 어미현상(Fishtailing)의 예측에 관한 연구

Prediction of Fishtailing in Ring Rolling by the 3-D Rigid-Plastic Finite Element Method

김광희, 양동열

초록

어미현상의 예측을 위하여 사각단면의 링을 환상압연하는 공정을 3차원 강소성 유한요소법으로 해석하였다. 환상압연공정의 점진적이고 변형영역이 두롤 사이 근처로 국한되므로 계산시간을 줄이기 위하여 두 롤 사이를 통과하는 부분만을 해석하였다. 변형도율의 분포, 압연력, 구동롤의 토오크, 링과 롤 사이의 접촉면에서의 압력분포 및 변형된 링의 단면모양을 계산하였다. 압연력, 구동롤의 토오크, 특히 변형된 링의 단면보양, 즉 어미현상은 계산결과와 실험이 잘 일치하였다.

The open-pass ring rolling of rectangular cross-section is simulated by the three-dimensional rigid-plastic finite element method to predict fishtailing. Because the ring rolling process is incremental and the deformation 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. The strain rate distribution, roll separating force, driven roll torque, normal pressure distribution and the cross-sectional configuration of the deformed ring are calculated. Comparisons between computation and experiment show good agreement in roll separating force, driven roll torque and especially in the cross-sectional configuration of the deformed ring, i.e. the effect of fishtailing.

Keywords:rigid-plastic finite element method/ring rolling/fishtailing

[References]

Hawkyard JB, Johnson W, Kirkland J, Appleton E, Int. J. Mech. Sci., 15, 873 (1973)
Yang DY, Ryoo JS, Choi JS, Johnson W, Analysis of Roll Torque in Profile Ring Rolling of L-sections, Proc. 21st Int. MTDR Conf., 69, London (1980)
Ryoo JS, Yang DY, Johnson W, Ring Rolling; The Inclusion of Pressure Roll Speed for Estimating Torque by Using a Velocity Superposition Method, Proc. 24th Int. MTDR Conf., 19, Manchester (1983)
Mamalis AG, Hawkyard JB, Johnson W, Int. J. Mech. Sci., 18, 11 (1976)
Yang DY, Kim KH, Int. J. Mech. Sci., 30, 571 (1988)
Yang DY, Lee CS, Cho HS, Lee CW, Cho NS, Ryoo JS, Development of a New Computer-Aided Manufacturing System for the Hot Ring-Rolling Process, Proc. 3rd ROMP Conf., 229, Kyoto (1984)
Park JJ, Kobayashi S, Int. J. Mech. Sci., 26, 165 (1984)
Yoon JH, Yang DY, Int. J. Mech. Sci., 30, 887 (1988)
Cook PM, True Stress-Strain Curves for Steel in Compression at High Temperature and Strain Rates, for Application to the Calculation of Load and Torque in Hot Rolling, Proc. Conf. Materials at High Rate of Strain, 86, Inst. Mech. Engrs., London (1957)
Mamalis AG, Johnson W, Hawkyard JB, J. Mech. Eng. Sci., 18, 184 (1976)
Mamalis AG, Johnson W, Hawkyard JB, J. Mech. Eng. Sci., 18, 196 (1976)

[1] Hawkyard JB, Johnson W, Kirkland J, Appleton E, Int. J. Mech. Sci., 15, 873 (1973)

[2] Yang DY, Ryoo JS, Choi JS, Johnson W, Analysis of Roll Torque in Profile Ring Rolling of L-sections, Proc. 21st Int. MTDR Conf., 69, London (1980)

[3] Ryoo JS, Yang DY, Johnson W, Ring Rolling; The Inclusion of Pressure Roll Speed for Estimating Torque by Using a Velocity Superposition Method, Proc. 24th Int. MTDR Conf., 19, Manchester (1983)

[4] Mamalis AG, Hawkyard JB, Johnson W, Int. J. Mech. Sci., 18, 11 (1976)

[5] Yang DY, Kim KH, Int. J. Mech. Sci., 30, 571 (1988)

[6] Yang DY, Lee CS, Cho HS, Lee CW, Cho NS, Ryoo JS, Development of a New Computer-Aided Manufacturing System for the Hot Ring-Rolling Process, Proc. 3rd ROMP Conf., 229, Kyoto (1984)

[7] Park JJ, Kobayashi S, Int. J. Mech. Sci., 26, 165 (1984)

[8] Yoon JH, Yang DY, Int. J. Mech. Sci., 30, 887 (1988)

[9] Cook PM, True Stress-Strain Curves for Steel in Compression at High Temperature and Strain Rates, for Application to the Calculation of Load and Torque in Hot Rolling, Proc. Conf. Materials at High Rate of Strain, 86, Inst. Mech. Engrs., London (1957)

[10] Mamalis AG, Johnson W, Hawkyard JB, J. Mech. Eng. Sci., 18, 184 (1976)

[11] Mamalis AG, Johnson W, Hawkyard JB, J. Mech. Eng. Sci., 18, 196 (1976)