Author(s)

F. J. Szabó

Abstract

The behaviour of the metal structure of a car seat subjected to impact loading has been investigated computationally by the finite element program system COSMOS/M, where a macro has been developed for the calculation of energy transformations during impact with the body of the driver in an accident. The finite element results and the calculated impact behaviour have been verified by an experiment. Having good agreement between the computational and experimental results, the macro calculating the behaviour data of the structure has been implemented to the optimization process for minimum mass. For the optimization the Random Virus Algorithm (RVA) is used, which is a new algorithm developed by the author for use in multidisciplinary optimization problems. The new concept of the algorithm is to model the very fast reproduction of biological (or computer) viruses, which give extremely good efficiency to the optimization algorithm. The optimization algorithm, the finite element model and the energy calculation are stored and running as one macro inside the finite element system. The results of the finite element calculations, experiments and of the optimization are presented in tables, finite element contour pictures and photos of the experiments. The method is able to take into account higher eigenmodes and eigenshapes therefore it can be applicable for higher speed impacts, too, after strong experimental verification. The macro makes it possible to use all the multidisciplinary or multiphysics features of the original finite element program system, therefore makes it possible to combine several phenomena during the multidisciplinary optimization, e.g. heat transfer or temperature dependent material characteristics with impact load, which can open new horizons for the optimization of structures for extreme loads during accidents, terror-attacks, explosions or tornados. A numerical example of the metal structure of a car seat is presented. Keywords: optimization, impact load, metal structures, programming FEM.

Keywords

optimization, impact load, metal structures, programming FEM.