LAUSR

Abstract The properties of the simulated lunar soil, which are of great importance to guide the investigation on the lunar due to the rarity and preciousness of the lunar soil, are extremely complex such that their precise probability distributions are hard to obtain but their bounds are easy to gain. In this study, an innovative non-random analysis method is developed to capture the ultimate soil shear stress based on the non-probabilistic convex model and Mohr–Coulomb failure criterion. Specifically, we extend the traditional Mohr–Coulomb failure criterion, which is usually in deterministic case, to an uncertain case by using a symmetrical positive definite matrix to characterize the correlation of the uncertain parameters related to the soil parameters. To obtain the upper and lower bounds of failure shear stress of the simulated lunar soil, the problem of calculating the stress bounds is converted into two optimization problems, which are solved by using Lagrangian method. Considering whether the time is involved or not in the uncertainties of the soil parameters, both time-invariant and time-variant interval uncertainties problems can be tackled by the proposed method. The effectiveness and accuracy of the proposed method is evidenced by numerical examples and data retrieved from the experimental results exactly between the upper and lower bounds. It indicates that the proposed method can provide important guidance for the design and optimization of lunar soil sampling mechanisms.