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Nonsteady Plane-strain Ideal Forming with Elastic Dead Zone

탄성 변형 영역을 고려한 비정상 평면 변형 이상 공정 이론

  • 이원오 (서울대학교 재료공학부) ;
  • 정관수 (서울대학교 재료공학부, 서울대학교 신소재공동연구소) ;
  • ;
  • 강태진 (서울대학교 재료공학부)
  • Published : 2004.10.01

Abstract

Ever since the ideal forming theory has been developed for process design purposes, application has been limited to sheet forming and, fur bulk forming, to two-dimensional steady flow. Here, application for the non-steady case was performed under the plane-strain condition based on the theory previously developed. In the ideal flow, material elements deform following the minimum plastic work path (or mostly proportional true strain path) so that the ideal plane-stram flow can be effectively described using the two-dimensional orthogonal convective coordinate system. Besides kinematics, fur a prescribed final part shape, schemes to optimize a preform shape out of a class of initial configurations and also to define the evolution of shapes and boundary tractions were developed. Discussions include the two problematic issues on internal tractions and the non-monotonous straining. For demonstration purposes, numerical calculations were made for a bulk part under forging.

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