On Frequency-Dependent Damping Coefficients In Lumped-Parameter Models Of Human Beings

Abstract

A three-degree-of-freedom model of the human body, which included both vertebral and visceral paths between the seat and head, was formulated and programmed for solution using the IBM Continuous System Modeling Program. The parameters representing spring stiffnesses and dampening coefficients were varied until the body-to-seat or head-to-seat acceleration ratios converged to existing experimental data at corresponding input frequencies. The model exhibited linear behavior for input frequencies up to approx. 6Hz and a possible transition region for input frequencies between 6 and 10Hz. For input frequencies between 10 and 30 Hz, visceral dampening was found to vary parabollically with input frequency