Title:
STRETCH FLANGE CRACK EVALUATION METHOD, METAL SHEET SELECTION METHOD, PRESS DIE DESIGN METHOD, COMPONENT SHAPE DESIGN METHOD, AND PRESSED COMPONENT MANUFACTURING METHOD
Document Type and Number:
WIPO Patent Application WO/2020/184712
Kind Code:
A1
Abstract:
The present invention provides technology for more easily evaluating stretch flange cracks in the sheared end face of a metal sheet under evaluation. The present invention includes at least two sets of reference strain gradient information (10c) with different forming conditions, said information being obtained by carrying out a forming analysis of a hole expansion test performed on an arbitrarily selected second metal sheet under predetermined forming conditions and converting the hole expansion ratio into a hole edge strain consisting of the true strain, and said information being the relationship between the hole edge strain and the radial strain gradient. The metal sheet under evaluation is subjected to hole expansion forming under the same respective forming conditions as the forming conditions corresponding to the at least two sets of reference strain gradient information (10c), and at least two limit hole expansion ratios for the hole expansion limit of the metal sheet under evaluation are calculated. A formable area (ARA) of the metal sheet under evaluation is calculated from the at least two sets of reference strain gradient information (10c) and the at least two limit hole expansion ratios for the hole expansion limit. Stretch flange cracks in the sheared end face of the metal sheet under evaluation are evaluated using the calculated formable area (ARA).
Inventors:
FUJII KENTO (JP)
SHINMIYA TOYOHISA (JP)
YAMASAKI YUJI (JP)
SHINMIYA TOYOHISA (JP)
YAMASAKI YUJI (JP)
Application Number:
PCT/JP2020/011189
Publication Date:
September 17, 2020
Filing Date:
March 13, 2020
Export Citation:
Assignee:
JFE STEEL CORP (JP)
International Classes:
B21D22/00; G06F30/10; G06F30/23
Foreign References:
| JP2019034312A | 2019-03-07 | |||
| JP2011140046A | 2011-07-21 | |||
| JP2010069533A | 2010-04-02 | |||
| JP2012170993A | 2012-09-10 | |||
| JP2019047363A | 2019-03-22 |
Other References:
EIJI IIZUKA ET AL., PLASTICITY AND MACHINING, vol. 51-594, 2007, pages 700 - 705
See also references of EP 3939713A4
See also references of EP 3939713A4
Attorney, Agent or Firm:
TANAKA Hidetetsu et al. (JP)
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