IFEM Various fixes and improvements for handling of 2D Lagrange meshes with non-uniform element types

Various fixes and improvements for handling of 2D Lagrange meshes with non-uniform element types

Open kmokstad opened this issue 11 months ago • 11 comments

This is a collection of several un-related fixes and improvements, to facilitate solving general unstructured Lagrange FE models read from external files. Among other things:

Tesselation of unstructured 2D patches with different element types (if a mix of quads and triangles are present).
Skip integration point loop entirely for elements with explicit matrices in 2D, flagged by negative nGauss. Also skip for 3-noded elements.
Accept non-continous external element index sequences
Option to fix all nodes within a specified box
Improved error handling for SuperLU (accept near-singular matrices, with warning)
Elimination of degenerated triangles created by merging duplicated nodes
Calculation of inverse nodal point mapping with output to VTF.

TODO: Still some work on result handling, permutation of element and element-node results if two or more element types. That can be a separate PR, when time comes..