Experimental Investigation of the Tractive Performance of an Instrumented Off Road Tire in a Soft Soil Terrain
Naranjo, Scott David
MetadataShow full item record
The main goal of this study is to improve the understanding of the interaction between a pneumatic tire and deformable terrain. A design of experiments has been implemented, that gives insight into the effect of individual tire and soil parameters, specifically wheel slip, normal load, inflation pres-sure, and soil compaction, as well as into the effect of combinations of such parameters on the tire and soil behavior. The results of such test data is exceedingly relevant, providing significant infor-mation to tire design for tire manufacturers, to users for operating conditions selection, as well as providing modeling parameters for tire models. Moreover, experimental investigation of tire-soil interaction provides validation data for tire models operating under similar conditions. In support of the validation of a soft soil tire model currently being developed at Virginia Tech under the auspices of the Automotive Research Center, experimental work has been performed on a low-speed, indoor single-wheel tester built to investigate studies in terramechanics. The terramechanics rig provides a well-controlled environment to assure repeatable testing conditions and void vehicle component ef-fects. The test tire for the rig is instrumented with a wireless sensory system that measures tire de-flection at the contact patch; combining this system with other instruments of the rig allows accurate estimations of wheel sinkage. A methodical soil preparation procedure has rendered great data to analyze several relations, such as the drawbar pull and the sinkage dependency on slip. The data col-lected indicated that, when looking at the effect of individual parameters, by increasing the soil com-paction, the normal load, and by decreasing the inflation pressure will result in a higher normalized drawbar pull. A higher normal load under all conditions consistently lowered the max tire sinkage depth. The sinkage has increased dramatically with the slip ratio, growing threefold larger at high slip (70-90%) when compared to lower slip (0-5%) ratios.
- Masters Theses