I/O Options and Subcase Information Entry The DENSITY command can be used in the I/O Options section to request density output for a topology optimization.


DENSITY (format_list, type, topo, peakoutput) = option


Argument Options Description
format <HM, H3D, OPTI, OP2, blank>
Results are output in HyperMesh results format (.res file).
Results are output in Hyper3D format (.h3d file).
Results are output in OptiStruct results format (.dens file).
Results are output in Nastran output2 format (.op2 file). 6
blank (Default)
Results are output in all active formats for which the result is available.
type <ALL, DES>

Default = DES

Results are output in all simulations.
DES, blank
Results are only output in the design history simulations.
topo <TOPO>

No default

Results are output only for topology design elements. Density values for non-design elements in the model are not output. Currently available only for the OPTI (.dens) format.
peakoutput <PEAKOUT>

Default = Blank

Only the filtered frequencies from the PEAKOUT Subcase and Bulk Data Entries will be considered for this output.
option <YES, ALL, NO, NONE, SID>

Default = YES

YES, ALL, blank
Results are output.
Results are not output.
Results are output for the specified set of elements (SID).


  1. When the DENSITY command is not present, density results are output.
  2. Density results are only available for topology optimizations.
  3. Outputting the density results in all simulations allows analysis results to be plotted on the density iso-surface in HyperView.
  4. The frequency of this output is controlled by the DESIGN keyword on an OUTPUT definition or, if no OUTPUT definition exists with the DESIGN keyword, by the DENSRES I/O Option.
  5. Multiple formats are allowed on the same entry; these should be comma separated. If a format is not specified, this output control applies to all formats defined by the OUTPUT command, for which the result is available.
  6. Density results are reported as element strain energy in the .op2 file.
  7. Multiple instances of this card are allowed. If instances are conflicting, the last instance dominates.