Journal of the Korean Society for Precision Engineering (한국정밀공학회지)

Korean Society for Precision Engineering (한국정밀공학회)
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Investigation on the Automatic Surface Generation for Extrusion Die of T-shaped Section using NURBS Surface and Area Mapping Method

NURBS 곡면과 면적 사상법을 이용한 T-형 압출 금형곡면의 자동생성에 관한 연구

  • 임종훈 (대진대학교 기계설계공학과 대학원) ;
  • 유동진 (대진대학교 컴퓨터응용기계설계학과)
  • Published : 2003.10.01
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Abstract

In order to construct the extrusion die surface of T -shaped sections, an automatic surface construction method based on NURBS surface and area mapping method is proposed in the present work. In the present study, a center point for area mapping is determined by introducing the mapping concept based on constant area proportionality between original billet and final product. The characteristic points of inlet profile are determined using the traditional area mapping method and the root finding numerical method. The inlet and outlet profiles are precisely described with NURBS curves using the characteristic points of entry and exit sections. For the construction of NURBS surface, an interpolation method for the pre-determined two section curves has been developed to be used in the generation of interior control points and weights. To show the validity of the proposed method, automatic die surface generation is carried out for the T-shaped section and T-shaped section with rounded corners.

Keywords

References

  1. Nagpal, V. and Altan, T., 'Analysis of the Three-Dimensional Metal Forming in Extrusion of Shapes with Use of Dual Stream Functions,' Proc. 3rd North American Met. Res. Conf. Pittsburgh, Pennsylvania, pp. 26-40, 1975
  2. Nagpal, V., 'On the Solution of Three-Dimensional Metal Forming Processes,' J. Eng. Ind. Trans. ASME Series B. Vol. 99, pp. 624-629, 1977 https://doi.org/10.1115/1.3439289
  3. Yang, D. Y. and Lee, C. H., 'Analysis of ThreeDimensional Extrusion of Section through Curved Dies by Conformal Transformation,' Int. J. Mech. Sci., Vol. 20, pp. 541-552, 1978 https://doi.org/10.1016/0020-7403(78)90012-7
  4. Gunasekera, J. S. and Hoshino, S., 'Analysis of Extrusion of Non-Circular Sections through Shaped Dies,' Annals of CIRP, Vol. 29, pp, 141-145, 1980 https://doi.org/10.1016/S0007-8506(07)61310-9
  5. Gunasekera, J. S., Gegel, H. L., Malas, J. C. and Doraivelu, S. M., 'Computer Aided Process Modeling of Hot Forging and Extrusion of Aluminum Alloys,' Annals of CIRP, Vol. 31, No. 1, pp. 131-136, 1982 https://doi.org/10.1016/S0007-8506(07)63283-1
  6. Yang, D. Y., Han, C. H. and Kim, M. U., 'A Generalized Method for Analysis of ThreeDimensional Extrusion of Arbitrarily Shaped Sections,' Int. J. Mech. Sci., Vol. 28, pp. 517-534, 1986 https://doi.org/10.1016/0020-7403(86)90050-0
  7. Shin, H. W., Kim, D. W. and Kim, N. S., 'A Simplified Three-Dimensional Finite-Element Analysis of the Non-Axisymmetric Extrusion Processes,' Journal of Materials Processing Technology, Vol. 38, pp. 567-587, 1993 https://doi.org/10.1016/0924-0136(93)90071-D
  8. Joun, M. S. and Hwang, S. M., 'Die Shape Optimal Design in Three-Dimensional Shape Metal Extrusion by the Finite Element Method,' lnt. J. Num. Methods Eng., Vol. 41, pp. 311-335, 1998 https://doi.org/10.1002/(SICI)1097-0207(19980130)41:2<311::AID-NME286>3.0.CO;2-2
  9. Celik, K. F. and Chitkara, N. R., 'Application of an Upper Bound Method to Off-Centric Extrusion of Square Section, Analysis and Experiments,' Int. J. Mech. Sci., Vol. 42, pp. 321-345, 2000 https://doi.org/10.1016/S0020-7403(98)00131-3
  10. Chitkara, N. R. and Celik, K. F., 'Extrusion of Non-Symmetric T-Shaped Sections, an Analysis and some Experiments,' Int. J. Mech. Sci., Vol. 43, pp. 2961-2987, 2001 https://doi.org/10.1016/S0020-7403(01)00044-3
  11. Celik, K. F. and Chitkara, N. R., 'Extrusion of Non-Symmetric U- and I-Shaped Sections through Ruled-Surface Dies : Numerical Simulations and some Experiments,' Int. J. Mech. Sci., Vol. 44, pp. 217-246, 2002 https://doi.org/10.1016/S0020-7403(01)00055-8
  12. Les Piegl and Wayne Tiller, The NURBS Book, Springer, 1995