In this paper, a novel portable sliding friction and wear test rig is introduced. Unlike other laboratory-based test setups, this setup can be used for both indoor and outdoor experiments. There is also no limitation on the size and type of the substrate surface that can be used for the friction and wear test in contrast to typical test rigs, which have some limitations for the size and type of substrate surface. A small six-wheel ground robot is developed to drag the sample on an arbitrary surface for a desired distance and velocity. A ground robot is an unmanned ground vehicle, capable of driving on the ground without humans on board. The speed of this robot can be measured and controlled precisely. The nominal normal load is adjusted using dead weights placed on the sample holder and the friction force is measured using a load cell. An adjustable sample holder was also designed and built to hold different-size specimens. The results of styrene–butadiene rubber block sliding on an asphalt track are presented to validate the test setup and illustrate the potential of the system for friction and wear testing. In addition, the effect of sliding velocity on the friction and wear is studied, and the correlation between the wear rate and the friction coefficient is investigated. These experimental results can be used to estimate the friction and life span of a tire tread compound on the real asphalt road. Finally, the formation of abrasion pattern observed on the rubber surface sliding on an asphalt track is discussed, which provides an insight into the understanding of dominant wear mechanism of tire tread compound on typical asphalt surfaces.
Reciprocating sliding friction and wear test apparatus