Can one do Design Sensitivity Analysis on Normal Modes

Numair

Can one do Design Sensitivity on Normal Modes deck, if so is there a sample deck to do that, and then to process in the NVH Module.

I have created the following deck, but I am not getting the dsa.0.h3d file.  This is the top portion of what I have created.

$$ optistruct
$
OUTPUT,H3DSENS,FL,USER
METHOD(STRUCTURE) = 16

$$------------------------------------------------------------------------------$
$$ Case Control Cards $
$$------------------------------------------------------------------------------$
$$
$$ OBJECTIVES Data
$$
$
$HMNAME OBJECTIVES 1objective
$
DESOBJ(MIN)=22
$
$
$HMNAME LOADSTEP 1"loadstep1" 3
$
SUBCASE 1
LABEL loadstep1
ANALYSIS MODES
METHOD(STRUCTURE) = 16
DESSUB = 35
$$--------------------------------------------------------------
$$ HYPERMESH TAGS
$$--------------------------------------------------------------
$$BEGIN TAGS
$$END TAGS
$
BEGIN BULK
$$
$$
$
$HMNAME OPTICONTROLS 1"optistruct_opticontrol" 1
$
DOPTPRM DESMAX 0

$HMNAME DESVARS 1Mat1_E1
DESVAR 1 Mat1_E1120000.050000.0 210000.0
$HMNAME DESVARS 2Mat1_nu1
DESVAR 2Mat1_nu10.2162 0.2 0.4
$HMNAME DESVARS 3Mat1_E2
DESVAR 3 Mat1_E2160000.050000.0 210000.0

RobHoglund

Hi Numair,

Design Sensitivity output in NVH module with the OUTPUT,H3DSENS command is designed for frequency response analysis only with DSA.  If you want to output the design sensitivities of your design variables with respect to your responses I recommend looking at the commands (along with DOPTPRM,DESMAX,0):

OUTPUT,MSSENS (output to sensitivities to Excel)

OUTPUT,HGSENS (output to sensitivities HyperGraph)

There are a few other output types as well for sensitivities, it depends on the type of optimization you're performing.  Refer the section "Gradient-Based Optimization Method" in the help for details.

Thanks,

Rob H.