Influence of unloading modes of spring-mass-damper models on vehicle to pole collision simulation results

Our intention, in this brief note, is to investigate what influence the viscoelastic models´ unloading properties have on models´ accuracy of representing vehicle crash event. Two types of simple spring-mass-damper systems (Kelvin models) such underdamped and critically damped conditions are analyzed. Subsequently, two different unloading scenarios are specified: elastic rebound in which only the damper is an energy dissipating element and plastic collision in which the model´s maximum achievable displacement is at the same time its constant deflection at the zero-force level. By comparing models´ behavior not only in terms of their time responses but also in terms of their force-deflection characteristics, it is concluded which of them is the most suitable to represent vehicle to pole collision.