An Investigation of the Effects of a Dynamic Vibration Absorber (DVA) to the Comfort of a Bus's Driver Seat

The frequency weighted acceleration, relative displacement, and Seat Effective Amplitude Transmissibility (SEAT) of a bus driver's seat are investigated by a 4 degrees of freedom (4DOF) vertical dynamic model, including a dynamic vibration absorber (DVA). The Root Mean Squared (RMS) values of the gain responses in the frequency domain are analyzed in the DVA damping ratio domain to help determine the optimal value of the DVA' s suspension. The obtained results show that the comfort evaluation index, in the case of a bus driver's seat with DVA, can be improved by more than 15% and nearly 10%, respectively, with the seat suspension natural frequency of 1~Hz and 4~Hz respectively. The comfort is better with the lower seat suspension natural frequency and vice versa. Especially in the case of both the seat and the DVA suspensions with low natural frequencies, all the three mean of evaluation indexes in the whole damping ratio domain of the DVA, have improved by more than 12%. This is the case with all three evaluation indexes which are the best when the damping ratio of the DVA is greater than 0.6.