Abstract
The purpose of this study is to understand dynamic characteristics of sitting human body which is exposed to multidimensional base excitation. By performing a vibrational test, transfer functions from the seat to the mouth and the forehead are measured with respect to three translational directions. Transfer functions of rotation of the head (pitch, roll) are calculated. Dynamic characteristics are estimated by using these transfer functions. In this paper. with focusing on the rotational motion of the head, the dependency of the transmissibility of transfer functions on the input vibration amplitude is examined experimentally. To investigate the non-linearity is essential so that the applicability of the linear model is considered. As a result, some non-linearity of the human body is revealed : the amplitude of transmissibilities decrease with increase of input vibration amplitude.
