# Matfrac

Use the Material Fraction optimization utility to set up an optimization problem to minimize the combined compliance index and constrain the volume fraction to be less than a user-defined value.

1. Click Matfrac.
2. Enter a matfrac value.
3. Click calculate.
The objective is set to minimize COMB for the entire model, while constraining the VOLFRAC for the entire model to be less than the MATFRAC value entered.