Human-structure interaction: Standing people subjected to vertical structural vibration

Frequency Response Functions (FRFs) for the vertical acceleration of a flexible single degree-of-freedom test rig with a standing body have been measured with sweeping harmonic vibration at frequencies between 2.7 Hz and 14 Hz. 18 subjects (6 female and 12 male) participated in the experiment. The two resonance frequencies of the human-structure system were clearly observed and generally decreased with increasing vibration magnitude. The fundamental natural frequency of the standing subjects varied between 5.23 Hz and 7.88 Hz, with average values of 6.82 Hz at the vibration magnitude of 0.5 ms(-2) and 6.64 Hz at 1.0 ms(-2). The average damping ratio was about 24%, with no obvious effect related to vibration magnitude. It was also observed that the FRF amplitudes for women were distinctly larger than those for men between 5.5 and 10 Hz for the two vibration magnitudes.