Experimental testing of an off-road instrumented tire on soft soil

• An experimental study on the pneumatic tire–deformable terrain interaction was conducted.
• Higher normal load, lower inflation pressure, and higher soil compaction improved the drawbar pull.
• The higher normal load had a negative impact on the tire performance past 60% slip.
• Newly developed WITS system provided good data for the tire carcass deflection.
• The experimental results from this study are used for validating the Hybrid Soft Soil Tire Model.

This study enhances the understanding of pneumatic tire–soft soil interaction through experimental work designed to investigate the effect of individual and combinations of tire/soil parameters on the tire/soil behavior. Its outcomes provide significant information to tire manufacturers, to users (for operating conditions selection), and to researchers (for modeling parameters and validation data).To support the development of the Hybrid Soft Soil Tire Model (HSSTM), funded by the Automotive Research Center (ARC), experimental work has been performed on the Terramechanics Rig at AVDL. Although separate publications detail the HSSTM, a short description of the model and its capabilities is also included here. The rig provides a well-controlled environment and ensures repeatable testing conditions. A wireless sensory system that measures tire deflection has been developed and employed for accurate estimation of wheel sinkage. The data collected indicated that, by increasing the soil compaction or the normal load, or by decreasing the inflation pressure results in a higher normalized drawbar pull. The combined effect of increase in soil compaction and decrease in inflation pressure yields an even higher normalized drawbar pull. The sinkage increased dramatically with the slip ratio, growing to values 3–4 times larger at high slip versus lower slip ratios.