Multibody modelling of pedestrian collisions requires the definition of contactimpact between the pedestrian and the vehicle. An examination of relevant impact test data reveals large rate-dependent components of the reaction force, permanent indentation, and concomitant energy loss. Contact-impact models previously used in simulations of pedestrian impacts typically have not adequately modelled one, two or all three of these phenomena. This paper presents a phenomenological contact-impact model based on the Hunt-Crossley model of impact, which includes rate-dependent damping, and is extended to include permanent indentation. The proposed model suitably characterises impact test data in a form that can also be implemented in the multibody simulation code MADYMO (Tass-Safe, Netherlands). The proposed contact-impact model was used to characterise the impact between a legform and the bumper of a vehicle, based on two impact tests conducted at different impact speeds. A single contact-impact definition in MADYMO closely reproduced the dynamics of both tests. The proposed model may be suitable in a wide range of impact conditions where the impact is modelled using multibody techniques and it is practicable to conduct impact tests as part of the modelling process. contact-impact properties, impact test, multibody simulation, nonlinear damping, pedestrian collisions
