Vertical Mode Human Body Vibration Transmissibility

Frequency response of standing humans subjected to sinusoidal vibration is presented. The vibratory input was a vertical displacement to the feet, and the output was the corresponding vertical response of the head. Twelve subjects (eight male and four female) were tested in the frequency range of 1-50 Hertz (Hz) with small input amplitudes (0.003 to 0.02 in). The twelve experimentally obtained frequency response plots were averaged and a sixteen-mass linear lumped-parameter model was developed to match the average response in both magnitude and phase angle. This proposed matching model is analogous to human anatomy. Parametric values of mass distribution and joint stiffnesses available in the literature were incorporated in the model. Damping parameters for various joints in the human body were indirectly determined from this study.