DSA

I/O Options and Subcase Information Entry The DSA command can be used in the I/O Options section to request Design Sensitivity Analysis results in a Frequency Response Analysis.

Format

DSA (TYPE, PEAKOUT, PROPERTY) = SID

Examples

DSA(DISP,PROPERTY)=12
DSA(VELO,PEAKOUT)=45
DSA(ACCE,PEAKOUT,PROPERTY)=23

Definitions

Argument Options Description
TYPE <DISP, PRES, VELO, ACCE, ERP> Available options:
DISP (Default)
Displacement
PRES
Pressure
VELO
Velocity
ACCE
Acceleration
ERP
Equivalent radiated power
PEAKOUT Default = blank If PEAKOUT is present inside the parentheses of the DSA entry, the filtered frequencies from the PEAKOUT card will be considered for DSA results.
PROPERTY Default = blank If PROPERTY is present: This indicates that design sensitivities represent the change in design response due to a change in design properties (instead of design variables).

If PROPERTY is not present: This indicates that design sensitivities represent the change in design response due to a change in design variables.
SID/ALL <SID, ALL>
SID
Refers to the ID of a SET of type GRIDC.
ALL
Requested values are output for all relevant entities.

Comments

  1. If multiple instances of the DSA request are defined within a subcase or outside all the subcases, then the union of all these instances will be used for the output.
  2. If the input deck does not contain any optimization data (apart from DESVARs), a MASS objective function is automatically created along with responses and constraints corresponding to the DSA request. If the input deck contains a valid optimization setup, then it is augmented with the DSA request.
  3. In the H3D file, the "SCALE" value is only printed when the PROPERTY argument is not present within the parentheses of the DSA entry. The sensitivities are pre-scaled when the PROPERTY argument is present in the DSA entry, so the scaling factor is not required in the H3D file.
  4. OUTPUT, H3DSENS can be used to include (or exclude) user-defined responses in the DSA output. DSA output (including user-defined responses) is limited to displacement, velocity, acceleration, acoustic pressure, ERP and powerflow DRESP1 responses.
    Output Sensitivities requested via the DSA output request (responses are automatically defined) Sensitivities output from a complete Optimization setup (User-defined responses via DRESP1)
    OUTPUT, H3DSENS, USER Yes Yes
    OUTPUT, H3DSENS, NOUSER Yes No
  5. Design variables and their corresponding design properties must be defined in the input deck if sensitivity output is requested through the DSA entry.
  6. DSA output for ERP is available for ALL panels. Set ID (SID) cannot be used and is ignored, if specified.