US 11,886,778 B2
Shifting a forming limit curve based on zero friction analysis
Thomas James Oetjens, Troy, MI (US); Thomas Lorne Chartrand, Clarkston, MI (US); and Alexander Paul Oetjens, Troy, MI (US)
Assigned to MAGNA INTERNATIONAL INC., Aurora (CA)
Filed by Thomas James Oetjens, Troy, MI (US); Thomas Lorne Chartrand, Clarkston, MI (US); and Alexander Paul Oetjens, Troy, MI (US)
Filed on Nov. 18, 2019, as Appl. No. 16/687,294.
Application 16/687,294 is a continuation in part of application No. 15/317,585, abandoned, previously published as PCT/US2015/034845, filed on Jun. 9, 2015.
Claims priority of provisional application 62/010,749, filed on Jun. 11, 2014.
Prior Publication US 2020/0082044 A1, Mar. 12, 2020
Int. Cl. G06F 30/20 (2020.01); G06F 17/15 (2006.01); B21D 22/20 (2006.01); G01N 3/28 (2006.01); G06F 30/333 (2020.01); G06F 113/24 (2020.01)
CPC G06F 30/20 (2020.01) [B21D 22/20 (2013.01); G01N 3/28 (2013.01); G06F 17/15 (2013.01); G06F 30/333 (2020.01); G06F 2113/24 (2020.01)] 20 Claims
OG exemplary drawing
 
1. A method for shifting a forming analysis based on zero friction analysis, comprising:
calculating a first alpha stress value from a ratio of a minor stress and a major stress from a predefined property of a hemispheric dome test of a die, the die being employed to deform sheet metal used to perform the hemispheric dome test;
determining a forming limit diagram (FLD) based on the major stress and the minor stress;
generating a second alpha stress value of a zero friction analysis of an upper fiber;
determining an alpha stress value ratio based on the first alpha stress value and the second alpha stress value;
generating a beta value of a zero friction analysis of a middle fiber;
generating a corrected zero friction test using the alpha stress value ratio and the beta value;
determining an updated FLD based on the major stress, the minor stress, and the corrected zero friction test; and
using the updated FLD to deform sheet metal using the die.