Features of Human Body Vibration

摘要

Fifteen sitting subjects were exposed to various levels of random vibrations in a vertical position. Transfer functions and coherence functions of head, shoulder and ilium responding to the seat were obtained. Nonlinearity of human response was observed , and the resonance frequencies were decreased with the increasing of the levels of vibration. The least square methods to fit the human transmissibility with "one-degree-of-freedom" and "two-degrees-of- freedom" models were utilized. The parameters of the models were determined. The precision of the prediction ability of models was proved. The dynamic models were used to predict the responses of the human body, which is useful for forest engineering applications and for protecting man from vibrations with fewer human tests,and even without human tests.