The problem is of a simplified vehicle moving at a constant velocity and crashing into a pole.
![vehicle_crash1.png](./resolveuid/551102aa1a29d563a1a76e87a923990a) | |
Fig. 1(a): Deformed vehicle after 50 ms | Fig. 1(b): Design variables with part numbers |
The problem illustrates the following features: - A simple single iteration optimization
- Dealing with an infeasible design formulation
- Use of composite functions
- Specifying an appended file for the simulation input
- Trade-off study
- Use of the LS-DYNA result interface
- Updating response surface approximations using the Repair feature
- Discrete-continuous optimization
| The criteria of interest are the following: - Head injury coefficient (HIC) of a selected point (15ms)
- Component Mass of the structural components (bumper, front, hood and underside)
- Intrusion computed using the relative motion of two points
Design variables: - The hood, front and underside (parts 3, 4 and 5 in Fig. 1(b)) are grouped under a single design variable: thood
- The bumper (part 2 in Fig. 1(b)) is identified as another design variable: tbumper
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Design Formulation
The design formulation is as follows:
- Minimize HIC(15 ms) subject to Intrusion (50 ms) < 550 mm. The intrusion is measured as the distance between the nodes 167 and 432 (for the location of the nodes see Fig. 1).
Possible Approaches for Problem Solution