FILTER_TYPE

The filter technique for the objective function can be changed using the parameter FILTER_TYPE in the optimization settings (OPT_PARAM command). Changing the filter technique for the objective function is mainly interesting for stiffness optimization problems.

The FILTER_TYPE can be set to STANDARD and LOW, respectively. The filter for FILTER_TYPE = LOW is a relaxation of the STANDARD filter. It is useful for coarse meshes yielding a clearer solid-void design and a lower number of optimization iterations. For reasonable and fine meshes FILTER_TYPE equal to LOW would often cause checkerboard.

FILTER_TYPE equal to LOW might also be useful for stabilizing dynamic problems like modal eigenfrequency optimization and frequency response optimization.

Important:
  • Changing the filter option has no effect when the objective is to minimize the mass.
  • Changing the filter option has no effect when manufacturing constraints are present.