Optimization Methodology for Innovative Automotive Crash Absorbers Definition in Different Vehicle Configurations

The simulation of vehicle crash impacts requires accurate and computationally expensive Finite Elements analysis. An effective procedure consists in considering and establishing what improvement can be made on an equivalent sub-model of the full vehicle. In this way, all the analysis can be performed on smaller models saving computational time. A full vehicle simulation is required only at the end of the design process to validate the results of the sub-model analysis.

The authors developed a software based on a genetic optimization algorithm in order to optimize the geometrical parameters of a variable thickness crash absorber reaching the same pulse profile in different vehicle configurations. A numerical study of the folding thin-walled aluminum tubes with variable thickness has been performed in order to achieve the same deceleration behavior for each configurations with maximum energy absorption-to-mass ratio. This would allow to define the best pulse profile in order to easily manage airbag control unit calibration and passive control system in each vehicle configuration.

Moreover, the performance in terms of folding length and peak forces have been considered.

Different optimization strategies have been implemented in order to find out the one that guarantees to achieve the optimization target with the lowest computational cost.

Results show how the approach proposed by the authors allows to obtain different variable thickness crash adsorber, one for each configuration, with the same pulse profile and better energy absorption-to-mass ratio, than the original constant thickness model.

The Author

Andrea Merulla