Forming Limit of Holed Dome in Two-Stage Stretch Forming

Abstract:

This paper deals with the accurate prediction of forming limit of a dome with a circular hole in two-stage stretch forming. Since this two-stage forming is a process of non-proportional deformation, a fracture criterion, which is capable to predict fracture limit of sheet metal under non-proportional strain path, is introduced. The limit dome height of steel blank is predicted by utilizing numerical optimization technique, in which the fracture criterion is used as a constraint function to avoid sheet breakage. The calculated result and the corresponding experimental result show that the fracture criterion can successfully predict the limit dome height in the two-stage forming while the classical forming limit diagram (FLD) overestimates it.

• Periodical: Advanced Materials Research (Volumes 146-147)
• Pages: 844-847
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.146-147.844
• Online since: October 2010
• Authors: Atsushi Hirahara, Ryutaro Hino, Fusahito Yoshida
• Keywords: Finite Element Analysis (FEA), Forming Limit Diagram (FLD), Non-Proportional Deformation, Numerical Optimization, Two-Stage Stretching Forming

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