Optimal Impact Isolation for Injury Prevention Evaluated by the Head Injury Criterion

Abstract

The optimal control of the deceleration of a particle moving along a straight line after an impact against an isolated surface is considered. The force applied to the particle by the surface is treated as the control variable. The deceleration distance is minimized subject to a constraint on the Head Injury Criterion functional. This functional is an integral criterion that is utilized in engineering biomechanics to evaluate the expected severity of impact-induced head injury of a human being. The solution obtained provides characteristics of the limiting capabilities for the prevention of head injuries by means of an impact isolator, such as a coating of the surface against which the impacts occur. The head injuries can be due to impact occurrences, including traffic crashes, falling, and contacts with ballistic objects.

Redesign of the vehicle bonnet structure for pedestrian safety

“…The normal acceleration reflects the rate of change in the direction of the head centre's motion or the rate of change in the direction of the head centre's velocity vector, while the tangential acceleration reflects the rate of decreasing amplitude of the head centre's velocity or the loss of the head's kinetic energy. However, previous studies have disregarded how the normal acceleration at the impact instant affects the HIC value, owing either to the lack of consideration of the change in the direction of the head centre's motion [7,14], or the assumption that the head centre's motion at the impact instant is directed along a straight line [15]. No previous research has assessed how the normal acceleration at the impact instant affects the HIC value.…”