Indentation tests and rolling simulations of a compliant wheel on soil at different consistencies

Abstract

The investigation presented addresses the response of a compliant wheel in interaction with deformable soil dependent on the water content, and accordingly on soil consistency. Two fine soils are considered. The basic soil properties and the soil shear strength are obtained from routine tests. A non-pneumatic Tweel in full size is tested in a loading device against a rigid base and against soil placed in a container in order to assess its stiffness and the compressional behavior of the soil, respectively. The measured pressure sinkage curves are then utilized in conjunction with a standard explicit FEM code to calibrate a hyperelastic model for the Tweel and an elasto-plastic constitutive model for the soil. Soil-tire interface strength is obtained from shear tests on a flat tire section embedded in soil. The numerical model is then applied to investigate how the water content affects the global response of the tire-soil system under different scenarios of free rolling, braking and driving. The methodology followed, complemented by appropriate soil testing, can be used as guide for the implementation of more elaborate models.