A STUDY ON DAMPED RESPONSE OF. A HUMAN BODY VIBRATING MODEL UNDER SITTING POSTURE

Abstract

In this work, modeling of vibratory system of human body and its study under sitting postures have- been presented. The human body is developed as a spring-mass-damper. . system. A generalized procedure for the vibratory modeling through anthropomorphic model and assumptions underlying are clearly stated. The inertial, stiffness values of the segments are obtained using anthropometric data and elastic modulii of bones and tissues. An initial effort was made to consider the viscosity of blood and synovial fluid in predicting the behaviour of the multi-degree damped vibratory systems. Three sets of effective damping coefficients were obtained on the basis of viscosity of blood and synovial fluid. In the present work two models of 16 degree of freedom corresponding to two sitting postures are considered. To study the effect of damping, the response of the head has been obtained for three different sets of damping coefficients. Similarly, the frequency response of other segments is also obtained for three sets of damping coefficients. The validation of the present work is done by developing the model for a 50th percentile U.S. male and comparing the frequency response with experimental response of U.S. male available in the literature. On the basis of this work, vibratory models of individuals can be framed which can predict the actual frequency response with reasonable accurac