How to solve Free element Edges in FEA meshing - FEA applications and Tutorials

Handling Free Element Edges

When we combine elements within a mesh, it may result in the creation of free edges in the interior of the mesh. It is mandatory to cross check and ensure that there are no free edges at the interior of the mesh , before sending the model to Solver.

For example, let us assume we combined four linear elements to create a single linear element (A). And now, the mid-nodes on the new element aren't connected to this element; they're connected to surrounding elements (B). (The new element isn't a 6-noded quadrilateral hybrid element.) Therefore, free edges occur in the interior of the mesh where the new element is adjacent to existing elements (C).

You can eliminate free element edges in one of two ways:
  • Use Combine Elements option to propagate the combined elements throughout the mesh. This eliminates all free element edges. Here:
A = mesh containing combined elements
B = combined groups of four elements
C = Free Element Edges verifies there aren't any free edges in the interior of the mesh.

  • Stitch the new elements into the mesh by using various combinations of Split Elements, Combine Elements, Delete, (Create) Element, and Node Connectivity commands. 
C = Use Free Element Edges to verify that there aren't any free edges in the interior of the mesh.