Optimization min(BeadFraction) whit DCON(frf erp)

Rahul_P1

Hi all,

i set up an Topografi optimization in HM for Optistruct. The objective is to minimize the beadfraction. As constraint I uses frf erp form my frequResponse loadstep. The analysis is running.

Some rows of the inputDeck:

--------------------------------------------------------------
DESOBJ(MIN)=2
SUBCASE 2
LABEL Frequenzanregung
ANALYSIS MFREQ
SPC = 5
METHOD(STRUCTURE) = 1
RESVEC(APPLOAD) = NO
FREQUENCY = 9
SDAMPING(STRUCTURE) = 100
DLOAD = 7
ACCELERATION(PUNCH,PHASE) = 1
ERP(PUNCH) = ALL
OLOAD(PUNCH) = 1
DESSUB = 2

BEGIN BULK
SET 1 GRID LIST
+ 127062
SET 3 ELEM LIST
+ 161291 145099 145100 145101 145102 145103 145104 145105

PANELG 4PANAL_Au ERP 3

DTPG 1PSHELL 1
+ 8.0 60.0 YES 7.0 NORM BOTH
+ BOUNDS 0.0 1.0
DRESP1 2 RES2_BeaBEADFRAC COMB
DRESP1 1 RES1_ERPFRERP AVG 4
DCONSTR 1 1 60000.0

DCONADD 2 1

The optimization starts but the defined constraint is not recognized!?!?
Where is the problem?

Rahul_P1

Hi Fliffer,

I can see the constraint is added in DCONSTR. DCONSTR 1 1 60000, refers to DRESP1 which is a FRERP with a lower bound of 60000.

Rahul_P1

Hi PrakashPagadala,

the constraint is defined in the InputDeck, rigth. But if I execute OptiStruct the ERPConstraint is not noticed. The .out says

Objective Function (Minimize BEAD ) = 9.00000E-01
No active constraints

Where is the Problem with this Constraint? Maby RESVEC() = NO

Rahul_P1

Hi FIliffer,

can you add the following card and run the analysis?

RESPRINT= ALL.

go to Analysis-->Control Cards-->RESPRINT and activate ALL in the card.

also, before running from OptiStruct panel, make sure Export option is set to ALL.

Please let me know if this helped you or not.

Rahul_P1

It works:

The problem was, my DCONSTR is satisfied. I have to apply a new upper bound. Whithout RESPRINT = all i didn't get it.

Thank You!