Attached
Parameters of the Road-Vehicle—Load system influence the vibration effects
generated at vehicular road transportation. Vertical vibration acceleration
(PSDmax) experienced by the tomato boxes and tomatoes within the box was
studied using the popular transport means in lllukkumbura area in Matale. The
road quality was estimated using the International Road Roughness Index (lRl).
Fully loaded Mitsubishi Canter truck at an average speed of 20 kmh'l on a road
rated at lRl between 2 to 3.5 mm/m registered increasing trend in the PSD of
vibration from the front side towards the rear side of the truck in the horizontal
direction. The observed average PSD values are in the approximate ratio, front :
middle : rear 2
l : 3: 6. Also the PSD of the vibration was found to be amplified
from the bottom stack towards the topmost stack in the vertical direction. The
observed average PSD values at 1“, 2nd, 3‘“, and 41h stacks are in the approximate
ratio, 1 : l : l.5 : 2.5. PSD of vibration was studied with a
fully loaded truck at
different speeds on a road consisting of segments rated at varying RI. The fully
loaded truck at different speeds on a road consisting of segments rated at varying
lRl registered varying PSD values of vibration. Even at lower speeds such as 25
kmh'I the vibration acceleration produced at “poor” quality (lRl > 5 mm/m)
roads was nearly 4 times higher compared to that produced at “fair" URI 2 to 3.5
min/m) or “good” quality (1R1 0.9 to 2 mm/m) roads. Registered pattern of the
PSD appears to be similar at the tomato boxes and at the tomatoes within the
same box.
