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An important basis of the technology strategy of the Partnership of a New Generation of Vehicles (PNGV), is the assumption that major advances in a number of different technologies must be made, before the realization of most of the challenging goals of the new generation of vehicles. One of those technologies is the reliance on lightweight alternative materials in order to produce lightweight components to achieve the projected fuel economy increases. However, this push toward lightweight components should not be on the basis of sacrificing vehicle performance, handling, reliability or safety. Toward this objective, engineers frequently are relying on super-fast computers as well as new approaches to achieve a new generation of designs of automotive components, based on some form of optimization techniques. These techniques however, usually imply increasing the number of constraints imposed on a particular design objective, which is the weight of the vehicle in this case.

A scheme which addresses the determination of the time step for time integration of non-linear explicit structural dynamic equations is described. Explicit time integration algorithms based on nodal partitions and mass scaling for crash applications are presented. This allows for greater advantage to be taken of local stability criteria, and thus improves the efficiency of the explicit time integrator. Consistency, convergence and stability analyses of this algorithm for first order systems are given. Issues relating to the effect of user selection of the proper technique on the outcome of the analysis, are discussed. The adequacy of the technique is evaluated by measuring its performance in various benchmark model problems. Example problems are included to demonstrate the accuracy and stability of the method. The stability conditions for general integration parameters in an element partition are also discussed.

During frontal and rear end type collisions, very large forces will be imparted to the passenger compartment by the collapse of either front or rear structures. NCAP tests conducted by NHTSA involve, among other things, a door openability test after barrier impact. This means that the plastic/irreversible deformations of door openings should be kept to a minimum. Thus, the structural members constituting the door opening must operate during frontal and rear impact near the elastic limit of the material. Increasing the size of a structural member, provided the packaging considerations permit it, may prove to be counter productive, since it may lead to premature local buckling and possible collapse of the member. With the current trend towards lighter vehicles, recourse to heavier gages is also counterproductive and therefore a determination of an optimum compartment structure may require a number of design iterations. In this article, FEA is used to simulate front side door behavior.