Abstract
The human body behaves like a vibrating physical system having mass, elastic and damping properties. In order to study the biodynamic behavior of the body, it is common practice to model the body as a lumped single or a multiple-degree-of-freedom (MDOF) system. Standards have been developed using the frequency-weighted root-mean-square (rms) acceleration input to the body as the primary measure of whole-body vibration exposure. In this paper, absorbed power during exposure to vertical whole-body vibration is considered as a potential indicator of the physical stress affecting comfort and health. A four-degree-of-freedom biodynamic model is chosen to represent the body and the absorbed power for the different body segments and the total body is computed. On the basis of the model and of the guidance provided in ISO 2631-1:1997 relating vibration exposure with health risk, computations are carried out to define a health guidance caution zone based on absorbed power.