Discrete Design Variables
Discrete design variable entities define and store discrete design variables for optimization problems.
Discrete design variables do not have a display state in the modeling window.
Nastran Cards
| Card | Description | 
|---|---|
| DDVAL | Define real, discrete design variable values for discrete variable optimization. Supported as a ddval entity. | 
OptiStruct Cards
| Card | Description | 
|---|---|
| DDVAL | Define real, discrete design variable values for discrete
                variable optimization or to define relative rotor spin rates in rotor
              dynamics. Note: Bulk Data
                  Entry |