Solution with LS-OPT

Define Solver and Input File

1. Select the Solvers tab.
2. For Command specify the LS-DYNA executable ls971_R4_2 (This name can be different on your computer).
3. For Input File browse the file main.k.
4. Enter a name for Name of Analysis Case, e.g. 1.
5. Push the Add button.

Define the Variables

1. Select the Variables tab. The variables are already defined in the input file main.k using *PARAMETER (see below) and therefore cannot be deleted.
2. For Type of tbumper switch the menu to Variable.
3. Enter 1 for the Minimum of the variable.
4. Enter 5 for the Maximum of the variable.
5. For Type of thood switch the menu to Variable.
6. Enter 1 for the Minimum of the variable.
7. Enter 5 for the Maximum of the variable.

Define the Responses

Define x-displacement of node 432

1. Select the Responses tab.
2. From the possible response types select: NODOUT.
3. For Node ID enter 432.
4. For Component select from the list Displacement.
5. For Direction select X Component.
6. For Response Name enter Disp2.
7. Push the Add button.

1. Stay in the Responses tab.
2. From the possible response types select: NODOUT.
3. For Node ID enter 167.
4. For Component select Displacement from the list.
5. For direction select X Component.
6. For Response Name enter Disp1.
7. Push the Add button.

1. From the possible response types select: NODOUT.
2. For Node ID enter 167.
3. For Component select Acceleration from the list.
4. Select the X Component.
5. From Select choose Maximum Value.
6. Enter 0.0 in the From time field (this will choose the max. value of acceleration in x-direction during the crash).
7. For Filtering choose SAE Filter.
8. Enter 60.0 for Frequency.
9. For Response Name enter MaxAccel.
10. Push the Add button.

1. From the possible response types select: Injury Criteria.
2. For Node ID enter 432.
3. For Component select from the list Head Injury Coef.
4. For Time interval select 15ms.
5. For Time unit select s.
6. For Length unit select mm.
7. For Response Name enter HIC.
8. Push the Add button.

Define mass responses for structural components

1. From the possible response types select: MASS.
2. In the List of Parts enter 2.
3. Push the (Add) > button.
4. Repeat the previous steps and create this list of parts:

   List of Parts:
   2
   3
   4
   5

   Note The part ID numbers can be found in Fig. 1(b): bumper (2), hood (3), front (4) and underside (5).

5. For Response Name enter MASS.
6. Push the Add button.
   

Define composite response intrusion of Disp1 and Disp2

1. From the possible response types select: Composite.
2. For Composite Components select Responses.
3. From Response select Disp2.
4. For Weight enter -1.0.
5. From Response select Disp1.
6. For Weight enter 1.0.
7. For Composite Function Type select Weighted.
8. For Response Name enter Intrusion.
9. Push the Add button.

Objective

1. Select the Objective tab.
2. From Response select HIC as the objective.
3. For Weight leave the default 1. If you have several objective functions, you may assign weight to each one according to their importance.
   

Constraints

1. Select the Constraints tab.
2. From Response select Intrusion as the constraint.
3. For Lower Bound accept the default -inf.
4. For Upper Bound enter 550.

Run LS-OPT

1. Select the Run tab.
2. Push the Run button. (Save the project as com.linear.single)