Creo Topology Optimization > Optimization Setup > Design Constraints > To Create a Mass Fraction Design Constraint
  
To Create a Mass Fraction Design Constraint
1. Click Home > Design Constraint. The Design Constraint dialog box opens.
2. In the Name box, type a name for the design constraint.
3. To change the color used for the design constraint, click , and select a color in the Color Editor dialog box.
4. To define the physical feature to use as a constraint, in the Response type box, select Mass Fraction (MASSFR).
5. To define all or a portion of the model to which the design constraint applies, next to Constraint target, do one of the following:
To apply the design constraint to the entire model, select the All design regions check box.
To apply the design constraint to only a portion of the model, clear the All design regions check box, and then do the following:
To include items for this design constraint, click the Volumes, Components collector, and then select volumes or components.
To exclude regions from the optimization for this design constraint, click the Excluded regions collector, and select volumes to exclude.
6. Under Constraint Bounds, type a value for Lower Bound and Upper Bound.
7. Select an option for Bound Type:
Actual—Use the actual value as the constraint bounds.
Scale of initial—Use a percentage of the initial response value as the constraint bounds.
8. Click OK.