Title: Techniques for reducing computational time in vehicle rollover simulations

Authors: P.R. Marur, S. Namdeo

Addresses: India Science Lab, General Motors R&D, ITP, Bangalore 560066, India. ' Easi India, J.P. Nagar III Phase, Bangalore 560078, India

Abstract: Numerical simulation of vehicle rollover requires nearly an order higher computation time compared to frontal/side impact simulations, as vehicle rollover event is several times longer than the other crash scenarios. The computation time can be considerably reduced if the deformable parts in the vehicle model can be switched to rigid during the rollover analysis. The Deformable-to-Rigid (D2R) switching, available as a standard option in the most explicit Finite Element (FE) codes, however, can be exercised only through systematic meshing of the components and by careful selection of the time of switching. This paper describes a method for setting up the FE model for multiple D2R switching, and selecting the time of switching based on system energy considerations. The dependence of the time of activation of D2R on the overall dynamics of the vehicle is demonstrated and a theoretical basis for the selection of time of rigid switching based on system energy is established using a 2-dof model. Curb trip rollover is simulated using a full FE model of a pick-up truck with the proposed method, and a reduction of 75% in computation time is achieved.

Keywords: deformable-to-rigid switching; D2R; vehicle rollover; rollover simulation; curb-trip rollover; crashworthiness; vehicle safety; FEM; finite element method; vehicle dynamics; pick-up trucks.

DOI: 10.1504/IJVS.2007.016752

International Journal of Vehicle Safety, 2007 Vol.2 No.4, pp.441 - 456

Published online: 21 Jan 2008 *

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