Agricultural tyre stiffness change as a function of tyre wear

Abstract

Vehicle designers use tyre characteristic parameters to parameterize tyre models during the design phase of a vehicle to determine the ride comfort, handling and performance. Tyre data is mostly presented only for new tyres with 100% tread on them. Soft terrain traction and minimal compaction have always been major requirements for agricultural tyres, however agricultural vehicles are increasingly being used on asphalt/non-deformable terrain as commercial farms are ever increasing in size. As operational costs are always forced to a minimum, agricultural vehicles operate with tyres ranging from new to fully used condition ranging from 100% down to almost 0% tread on them. During the operational life of a tyre the tyre characteristics change as the tyre tread wears down. This study investigates the change in tyre characteristics on hard terrain with tyre wear at a single load condition, two different inflation pressures and three tread wear conditions. Significant trends are noted with dramatic changes in traction and tyre stiffnesses as the tyre wear changes.