Paper Number 3.4
Evaluation
of the Contact Pressure Distribution
of a Rear Combine
P.A. Misiewicz[1]
T.E. Richards
K. Blackburn
M.J. Hann
R.J. Godwin
School of Applied Sciences
Cranfield
Bedfordshire
MK43 0AL
Email: p.misiewicz.s06@cranfield.ac.uk
Voice: +44 7752954149
Only a vehicle’s tyres
have contact with the ground on which they roll, therefore, the tyre contact
patch transmits all the forces from the vehicle to the ground. Furthermore, the
size of tyre contact patch and contact pressure distribution affect the forces
acting on the wheel which are traction force, rolling resistance and braking
force. It determines the vehicle's grip, wear on the rubber and fuel
consumption.
The aim of this paper
is to report on the findings of the research which involved the development of
a method to estimate tyre contact pressure and its distribution. The results of
an investigation into the contact pressures obtained when a smooth rear combine
tyre was loaded on a hard surface are presented. The tests employed a
piezo-electric pressure mapping system. The experiments involved placing the
pressure sensors on an un-deformable surface and loading them with a rear
combine tyre at a range of inflation pressures and loads. This method allowed
an accurate measurement of the mean and maximum contact pressure, and pressure
distribution across the contact area.
The results obtained
indicate non-uniform pressure distribution across the contact patch. The
findings gave an understanding of the influence of tyre inflation pressure and
load on the resulting contact pressure which contributed to a better
understanding of tyre behaviour.