Tri-Axial Vibration of the Head of Car Driver under Different Seating Conditions
Previous studies have quantified the biodynamic responses to vibration in a laboratory set-up using mainly rigid seats and single axis excitation. This study investigates the effect of the backrest contact, headrest contact, backrest angle, arm angle and the extent of gripping the steering wheel on the acceleration of the head in a real life multi-axis vibration environment. Fifteen male subjects drove a car on a paved road at a speed of 40 km/h adopting one of eight seating conditions at a time. The acceleration of the head was measured in the x, y and z-directions during the exposure duration. The results were presented as r.m.s. values and PSDs of the accelerations of the head. The greatest effect on the acceleration of the head resulted from using the backrest and the headrest. The arm angle and the extent of gripping the steering wheel showed no or little effect on the acceleration of the head. The effect of the seating conditions was found generally different from that reported in studies conducted in the labs with single, dual, or tri-axial vibration exposure.