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Discrete optimization

Solving the optimization problem with a discrete variable.

Solution with LS-OPTui

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Solution with LS-OPTui

Variables

Variables

Load the com.linear file you created in the first part or download the input file above.

Modify the Variable thood

  1. Select the Variables panel.
  2. Switch the Type from the variable thood to Discrete Var.
  3. Enter the distinct values in the text box 1 2 3 4 5 (separated by a space).
discrete_variable1.png

Run

Run

Run Panel

  1. Select the Run panel.
  2. For Number of Iterations enter 10.
  3. Push the Run button.
discrete_run1.png

Com-file

Com-file

The created command file may look like this:

"Optimization Problem"
$ Created on Wed Jan 2 14:26:04 2008
solvers 1
responses 5
$
$ NO HISTORIES ARE DEFINED
$
$
$ DESIGN VARIABLES
$
variables 2
Variable 'tbumper' 3
Lower bound variable 'tbumper' 1
Upper bound variable 'tbumper' 5
Variable 'thood' 1
Variable 'thood' discrete {1 2 3 4 5}

$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ OPTIMIZATION METHOD
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
Optimization Method SRSM

$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ SOLVER "1"
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
$ DEFINITION OF SOLVER "1"
$
solver dyna960 '1'
solver command "/home/prak1/LS-DYNA/ls971_s_7600_1224_ia32_redhat90"
solver input file "/home/prak1/LS-OPT/beispiele/crash_optimization/files/discrete/main.k"
solver check output on
solver compress d3plot off
$ ------ Pre-processor --------
$ NO PREPROCESSOR SPECIFIED
$ ------ Metamodeling ---------
solver order linear
solver experiment design dopt
$ ------ Job information ------
$
$ RESPONSES FOR SOLVER "1"
$
response 'Disp2' 1 0 "BinoutResponse -res_type Nodout -cmp x_displacement -id 432 -select TIME "
response 'Disp1' 1 0 "BinoutResponse -res_type Nodout -cmp x_displacement -id 167 -select TIME "
response 'MaxAccel' 1 0 "BinoutResponse -res_type Nodout -cmp x_acceleration -id 167 -select MAX -start_time 0.0000 -filter SAE -filter_freq 60.0"
response 'MASS' 1 0 "DynaMass 2 3 4 5 MASS"
response 'HIC' 1 0 "BinoutResponse -res_type Nodout -cmp HIC15 -gravity 9810.0 -units S -id 432"

composites 1
$
$ COMPOSITE RESPONSES
$
composite 'Intrusion' type weighted
composite 'Intrusion' response 'Disp2' -1 scale 1
composite 'Intrusion' response 'Disp1' 1 scale 1
$
$ OBJECTIVE FUNCTIONS
$
objectives 1
objective 'HIC' 1
$
$ CONSTRAINT DEFINITIONS
$
constraints 1
constraint 'Intrusion'
upper bound constraint 'Intrusion' 550
$
$ JOB INFO
$
iterate param design 0.01
iterate param objective 0.01
iterate param stoppingtype or
iterate 10
STOP

Results

Results

Comparison of the results of the continuous and discrete analysis.

 

 ContinuousDiscrete
thood3.8482
tbumper1.6493.5574
HIC163.2221.3
Mass0.60960.6717
Intrusion549.42536.65

Download

Download

The complete data set (input and command files) is available for download as tar.gz crash_discrete.tar.gz or zip-file crash_discrete.zip.