An active head-neck model in whole-body vibration: Vibration magnitude and softening

An active head-neck model is introduced in this work to predict human-dynamic response to different vibration magnitudes during fore-aft whole-body vibration. The proposed model is a rigid-link dynamic system augmented with passive spring-damper tissue-like elements and additional active dampers that resemble the active part of the muscles. The additional active dampers are functions of the input displacement, velocity, and acceleration and are based on active control theories and a kd-tree data-searching scheme. Five human subjects exposed to random fore-aft vibration with frequency content of 0.5-10 Hz were tested under different vibration with magnitudes of 0.46 m/s2, 1.32 m/s2, and 1.66 m/s2 rms. The results showed that the proposed model was able to reasonably capture the softening characteristics of the human head-neck response during fore-aft whole-body vibration of different magnitudes.