
Mass constraint

Specify the targeted mass that the
part will be reduced by during optimization. Select one of the following:
Reduce mass by
(percentage)

Type the targeted percentage of mass
reduction.

Reduce mass by (absolute
value)

Type the exact value of the mass to
remove from the part's maximum design space.

The optimization algorithm will attempt to reach the targeted
mass reduction for the final shape through an iterative
process. 

Displacement
constraint

Specifies the upper limit for the
selected displacement component. In
Component, select the required displacement
variable. Select one of the following:
Specified
value

Type the targeted value for the selected
displacement variable, and specify the required units in
Units.

Specified factor

Type a factor to multiply the maximum
displacement calculated from a static study.

Select one of the following for a reference vertex location for
the displacement constraint:
Automatic (single max point)

The program selects by default the
vertex of the maximum displacement observed in the
model.

User defined

Select in the graphics area the
reference vertex for the displacement constraint.



Frequency
Constraint 
Mode Shapes

Add the number of mode shapes to enforce a frequency
constraint during optimization. Before you run a
topology study, run a frequency study with the
original model (maximum design space) to evaluate
the range of permissible natural
frequencies.

Comparator

Select one of the three options: is less
than to enter an upper frequency limit,
is greater
than to enter a lower frequency limit,
or is between to
enter a range of permissible frequencies for the
selected mode shape (for example, 1020).

Value (Hz)

Enter the frequency values in Hz for each mode
shape.

Mode tracking

When selected, the optimization solver tracks the order
of the selected mode shapes as derived from the original
geometry when enforcing frequency constraints throughout
the optimization iterations. When Mode
tracking is cleared, the solver tracks
the current order of mode shapes as derived for each
optimization iteration. For example, it is possible for
an optimization goal of a 50% mass reduction and a
frequency constraint on the first mode shape, the first
mode shape of the original geometry becomes the second
or third mode shape of the optimized geometry.

For example, you add a frequency constraint on a distinct
bending mode shape of a plate (the first mode in the original
plate geometry). As the model shape changes during iterations,
this distinct bending mode may move down in the frequency list.
By selecting Mode tracking, the solver
keeps track of the same mode as it moves positions in the list
of frequencies, and enforces the constraint on the same mode
shape. When you clear Mode tracking,
another mode shape may replace the original first bending mode
in the course of iterations. The solver then applies the
frequency constraint on this new mode that replaces the old
mode.


Stress/Factor of Safety
Constraint 
Stress Constraint

Select Specified value to
enter the maximum permissible von Mises stress for the
optimized geometry. Select Specified percentage to enter the
maximum permissible von Mises stress as a percentage of
the material's yield strength.

Factor of Safety Constraint

Enter a minimum factor of safety value for the optimized
geometry. The default failure criterion is the Maximum
von Mises stress.

