Method of Self Adaptive Rezoning for the Case of Large Deformation Finite ElementProblems Utilizing Rezoning Indicators Derived from Eigenvalue Testing

摘要

Rezoning is required when elements within a Lagrangian based finite element meshbecome distorted due to large deformations and strains. Rezoning halts the solution process to correct distorted elements which cause inaccuracies and ill conditioning. The solution is restarted after the remeshing and the remapping of the element variables in the rezoning regions. To date the rezoning process has remained an interactive process with very little theory. A method for self adaptive rezoning is delineated based upon finite element modeling assumptions of structural problems involving large deformations and strains. Linear isoparametric quadrilateral elements using selective reduced integration are examined. Geometrical measures of an element are defined in terms of aspect ratio, taper ratio, and skew angle. The amount of distortion of an element is related to these terms when compared to the same terms for an ideal element.