Global Search Option
The global search option is incorporated directly in OptiStruct. It does not require an external program to run with OptiStruct.
It is activated by the DGLOBAL Bulk Data and I/O Options Entries.
DGLOBAL = 10
...
BEGIN BULK
...
DGLOBAL 10
Engine Mount Optimization Example
PARAM, MASSPROP
DGLOBAL = 10
SENSITIVITY = ALL
SENSOUT = FL
$
INCLUDE '/ANALYSIS/H3D_FILES.dat'
TITLE = ENGINE MOUNT LOCATION OPTIMIZATION
$ ENGINE MOUNT LOCATIONS
SET 400 = 6966 6967 6968 6998 6999 7000
DESVAR = 400
DESOBJ = 1
RANDOM = 2400
SET 2 =1006001,9006002
ACCE(SORT1,PHASE,PLOT,PSDF) = 2
SUBCASE 10 $RIGHT SIDE INPUT
DLOAD=10
ANALYSIS = MFREQ
FREQUENCY = 100
SPC = 1
MPC = 400
METHOD = 1
SUBCASE 20 $LEFT SIDE INPUT
DLOAD=20
FREQUENCY = 100
ANALYSIS = MFREQ
SPC = 1
MPC = 400
METHOD = 1
$
OUTPUT(XYPLOT)
XYPUNCH ACCE PSDF / 1006001(T1)
XYPUNCH ACCE PSDF / 1006001(T2)
XYPUNCH ACCE PSDF / 1006001(T3)
XYPUNCH ACCE PSDF / 9006002(T1)
XYPUNCH ACCE PSDF / 9006002(T2)
XYPUNCH ACCE PSDF / 9006002(T3)
BEGIN BULK
$-------------------------------------------------------------------------------
$ PARAM CARDS FOR ANALYSIS
PARAM WTMASS 1.
$==01==><==02==><==03==><==04==><==05==><==06==><==07==><==08==><==09==><==10==>
$
FREQ1 1 1.0 0.2 95
EIGRL 1 45.0
$
$-------------------------------------------------------------------------------
$==01==><==02==><==03==><==04==><==05==><==06==><==07==><==08==><==09==><==10==>
DOPTPRM DESMAX 50
DGLOBAL 10
$-------------------------------------------------------------------------------
$==01==><==02==><==03==><==04==><==05==><==06==><==07==><==08==><==09==><==10==>
$
$-----------------------------------------------------------------------$
$ Left Engine Mount Point of Action
$
GRID 4500 1250.0 -325.0 747.0
GRID 4505 1250.0 -325.0 747.0
GRID 4501 1260.0 -325.0 747.0 123456
GRID 4503 1250.0 -325.0 757.0 123456
CBUSH 5955 5964 4505 4500 5901
CORD1R 5901 4500 4503 4501
$--1---|---2---|---3---|---4---|---5---|---6---|---7---|---8---|---9---|-------|
RBE2 5961 4004501 123456 4500
RBE2 5962 6004501 123456 4505
CONM2 5956 6004501 00.0035 0.0 0.0 0.0
CONM2 5957 4004501 00.0035 0.0 0.0 0.0
DESVAR 6966 EM4501X 10.0 -70.00 80.00 0.2
DVGRID 6966 4505 1.0 1.0 0.0 0.0
DVGRID 6966 4500 1.0 1.0 0.0 0.0
DESVAR 6967 EM4501Y 10.0 -60.00 30.00 0.2
DVGRID 6967 4505 1.0 0.0 1.0 0.0
DVGRID 6967 4500 1.0 0.0 1.0 0.0
DESVAR 6968 EM4501Z 10.0 -90.00 70.00 0.2
DVGRID 6968 4505 1.0 0.0 0.0 1.0
DVGRID 6968 4500 1.0 0.0 0.0 1.0
$--1---|---2---|---3---|---4---|---5---|---6---|---7---|---8---|---9---|-------|
PLOTEL 5977 6004501 4501
PLOTEL 5979 6004501 4503
$
PBUSH 5964 K 450.0 300.0 500.0 0.0 0.0 0.0
B 0.0 0.0 0.0 0.0 0.0 0.0
GE 0.040 0.040 0.040 0.0 0.0 0.0
$-----------------------------------------------------------------------$
$ Right Engine Mount Point of Action
$
$
GRID 4510 1250.0 325.0 747.0
GRID 4515 1250.0 325.0 747.0
GRID 4511 1260.0 325.0 747.0 123456
GRID 4517 1250.0 325.0 757.0 123456
CBUSH 5964 5964 4515 4510 6001
CORD1R 6001 4510 4517 4511
$--1---|---2---|---3---|---4---|---5---|---6---|---7---|---8---|---9---|-------|
RBE2 5994 4004511 123456 4510
RBE2 5995 6004511 123456 4515
CONM2 5996 6004511 00.0035 0.0 0.0 0.0
CONM2 5997 4004511 00.0035 0.0 0.0 0.0
DESVAR 6998 EM4511X 10.0 -75.00 80.00 0.2
DVGRID 5998 4515 1.0 1.0 0.0 0.0
DVGRID 5998 4510 1.0 1.0 0.0 0.0
DESVAR 6999 EM4511Y 10.0 -20.00 80.00 0.2
DVGRID 6999 4515 1.0 0.0 1.0 0.0
DVGRID 6999 4510 1.0 0.0 1.0 0.0
DESVAR 7000 EM4511Z 10.0 -65.00 60.00 0.2
DVGRID 7000 4515 1.0 0.0 0.0 1.0
DVGRID 7000 4510 1.0 0.0 0.0 1.0
$--1---|---2---|---3---|---4---|---5---|---6---|---7---|---8---|---9---|-------|
PLOTEL 6011 6004511 4511
PLOTEL 6013 6004511 4517
PLOTEL 24511 6004511 4004511
INCLUDE '/ANALYSIS/OPTIMIZATION_CARDS.dat'
INCLUDE '/ANALYSIS/SIMPLE_ROAD_INPUT.dat'
INCLUDE '/ANALYSIS/CONNECTIONS_WO_ENGING_MOUNTS.dat'
INCLUDE '/ANALYSIS/NON_H3D_FILES.dat'
ENDDATA
In this model, the left and right mount locations are being optimized for improving the driver's seat track for a simple rough road shake input. A majority of the component files are in the CMS super element format. The simple component files are in OptiStruct. The super elements are required in order to make each optimization run faster.
This run will consist of several optimization runs from different starting points. Each optimization output will be added into a separate directory. The .pch files from each directory can be viewed in HyperGraph and the best results can be chosen.
The resulting .grid file for the best results can be included in the basic model file by the ASSIGN,UPDATE card. This will automatically update the engine mount locations for you.