EFFECTS OF HELMET WEIGHT AND CENTER-OF-GRAVITY ON THE VIBRATORY DYNAMICS OF THE HEAD-NECK SYSTEM: A MODELING APPROACH

摘要

A four degree of freedom mathematical model was developed to describe the effects of varying helmet weight and center-of-gravity (CG) on the vibration characteristics of the head-neck-helmet system. The model consists of two pivot points connected by a system of rotational springs. Experimental data, collected from six subjects exposed to single- and multiple-axis vibration while wearing a variable weight/variable CG helmet, was used to determine rotational spring coefficients. Data from a simplified model was compared to experimental head-neck motion data to illustrate the change in head-neck-helmet motion due to the change in helmet weight and CG. Eventual optimization of the mathematical model will produce a useful tool to predict changes in pilot head-neck motion due to changes in helmet design.