Quantification of constant stiffness force-shortening model parameters for vehicles tested under United States side impact protocols

Abstract

This study presents a methodology for deriving all coefficients of the constant stiffness force-shortening model for the sides of vehicles tested under the United States Federal Motor Vehicle Safety Standard 214 dynamic and high-speed lateral New Car Assessment Program tests. The method utilizes the a priori known moving deformable barrier configuration and velocity vector at impact as a constraint for the momentum transfer that occurs between the collision partners. The zonal force balance method is then used to reduce the global momentum exchange relationships to solve for the damage onset speed for the geometrically reduced and structurally homogenized two-dimensional model for the test vehicle. The calculated damage onset speed is then used in conjunction with the dimensional properties, inertial properties and the shortening profiles of the collision partners in conjunction with the known model coefficients for the moving deformable barrier in order to solve for the Campbell linear stiffness and the CRASH3 stiffness coefficients.

Keywords:

• Force-shortening model
• lateral impact
• accident reconstruction