The purpose of this functionality is to provide an iso-density surface based on the volumetric density information from a topology optimization. Through tetrameshing for 3D models and inheriting boundary conditions, the results from FEA topology can be used for quick reanalysis.

FEA topology support is available for first and second order shell and solid elements. For 3D models, the recovered iso-surface can be tetrameshed-by-property automatically. FEA topology provides two options for the processing of non-design elements: Keep smooth narrow layer around and Split all quads. Keep smooth narrow layer around will retain an artificial layer of elements around the non-design space in the interpretation, and Split all quads will split quad elements in the non-design space, if present, to generate a tetra connection between design and non-design regions. Finally, FEA topology preserves boundary conditions by inheriting them from the original model (<prefix>.fem). Those boundary conditions unattached to nodes/elements after geometry recovery are deleted to ensure reanalysis.

An example of FEA topology for reanalysis is shown below with the following input data definition:

Result of FEA topology for reanalysis

The same model is run, this time with Keep smooth narrow layer around on, and Split all quads off. This approach creates a layer of elements around the non-design region and pyramids around the quad elements, if quads exist, to connect to the design space tetrahedral elements.

Result of FEA topology with a layer of elements around non-design space

Tetramesh will be applied on the iso-surface result if there is one close volume at least. The advantages of the tetramesh in FEA topology include: