Citation

Patil MK, Palanichamy MS. Math. Model. 1985; 6(5): 421-442.

Copyright

(Copyright © 1985, Elsevier Publishing)

DOI

10.1016/0270-0255(85)90063-6

PMID

unavailable

Abstract

Experimental studies of the vibrations transmitted to and tolerated by tractor and truck drivers indicate that the drivers are subjected to extremely uncomfortable levels of vertical and pitch vibrations in the frequency range of 0.5 to 11 Hz. In this study, an occupant-tractor system is modeled as a lumped parameter system. The composite model is simulated for vertical and pitch vibrational response to ground reaction by steady-state sinusoidal forcing function inputs and for transient responses by trapezoidal type of inputs. A relaxation type seat suspension located in the plane of the center of gravity of the chassis of a tractor is introduced, and the parameters of the seat suspension are determined for minimized human body responses. When these responses are compared with those of an optimized relaxation seat suspension located behind the center of gravity at the conventional location of a tractor and also with the experimental results of other investigators, it is found that the recommended location is the best among those considered. It reduces all the human body-segment responses significantly and the acceleration level to much below the eight-hour 'exposure limit' tolerance curve, and thus improving riding comfort.