Analytical study of stress distribution models for estimation of stresses beneath plain rigid wheels and a vertical force on TRI-1 lunar soil simulant

In this paper, three stress distribution models are considered, namely: Reece from 1965, Bekker from 1969,Wong-Reece from 1967. Two types of wheels are considered for the preset study, i.e., a small wheel with diameter of 160mm and width 32mm, whereas for a large wheel with diameter of 210mm and width of 50mm. TRI-1 or Tiruchirappalli soil simulant is considered for the interaction studies, which is an anorthosite based lunar soil simulant. The normal stress, shear stress and vertical forces are determined when the wheel starts moving on TRI-1 soil simulant. Entry and exit angles are also calculated for all models to estimate vertical forces. The maximum normal stress found for the small wheel was 32.121 kN/m2 (Wong-Reece model). In the case of the large wheel, the maximum normal stress was found to be 39.016 kN/m2 (Reece model). Vertical forces are found from the obtained normal stresses and shear stresses, and are presented graphically. The dimensionless stress ratio of both the wheels for the considered models, i.e., DNSR and DSSR, is also found.