The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 14, 1995
Filed:
Oct. 28, 1993
Sing C Tang, Plymouth, MI (US);
James C Carnes, Willis, MI (US);
Ford Motor Company, Dearborn, MI (US);
Abstract
Method for predicting post-buckling deformation of a sheet of metal during a draw forming process, for use with a computer including memory, by introducing a set of springs to stabilize the sheet metal close to the onset of buckling, thereby enhancing convergence of numerical solutions. The method is for use with sheet metal forming tools including a draw die, a punch and binder having surfaces designed to form the sheet metal into a part, the sheet metal being represented as a mesh including a plurality of nodes. The method includes applying a displacement increment to the sheet metal nodes and identifying a singularity in a tangent stiffness matrix associated with the sheet metal close to the onset of buckling. The method also includes introducing a plurality of springs at the sheet metal nodes so as to eliminate the singularity and enhance convergence of the numerical solution of the displacement increment.