# Minimize Mass

Minimizing mass is one of several optimization objectives, and is available with topology, gauge, and lattice optimization.

## Minimizing Mass for Topology Optimization

When running a topology optimization, minimizing the mass of a design space will result in a shape that is the lightest weight possible that can still support the applied loads. If you select Minimize Mass as your optimization objective, you will need to specify one or more of the following:
1. Stress Constraints - applied using the Run Optimization window and specified in terms of a safety factor.
2. Frequency Constraints - applied using the Run Optimization window.
3. Displacement Constraints - applied using the Displacement Constraints tool.
Note: Once optimization is complete, the best result when minimizing mass is generally found by dragging the topology slider to the far right in the Shape Explorer.

## Minimizing Mass for Gauge Optimization

When running a gauge optimization, minimizing the mass of a design space will change the thickness of the part to minimize mass. If you select Minimize Mass as your optimization objective, you will need to specify one or more of the following.
1. Stress Constraints - applied using the Run Optimization window and specified in terms of a safety factor.
2. Displacement Constraints - applied using the Displacement Constraints tool.
3. Frequency Constraints - applied using the Run Optimization window.

## Minimizing Stiffness for Lattice Optimization

When running a lattice optimization, minimizing the mass of a design space will result in a shape that is the lightest weight possible that can still support the applied loads. If you select Minimize Mass as your optimization objective, you will need to specify one or more of the following:
1. Lattice - applied using the Run Optimization window.
2. Stress Constraints - applied using the Run Optimization window and specified in terms of safety factor.
3. Frequency Constraints - applied using the Run Optimization window.
4. Displacement Constraints - applied using the Displacement Constraints tool.

## Example 1: Minimizing Mass Subject to Stress Constraints

The motorcycle bracket pictured below was optimized by minimizing mass subject to stress constraints, defined in terms of a minimum safety factor. As the safety factor increases, more material to resist the loads you've applied.

## Example 2: Minimizing Mass Subject to Stress and Displacement Constraints

A displacement constraint can be applied to restrict a certain point on your model from deflecting more than a specified distance from its original location. In the example images below, a displacement constraint has been applied to the foot peg of the motorcycle bracket in addition to a stress constraint. As the allowable displacement at the peg decreases, the optimized shape requires more material to resist the deflection.
Note: When using displacement constraints, we recommend applying stress constraints as well. If used alone, displacement constraints can bias the optimization, resulting in disconnected areas, as shown in the first image below: