On the basis of the discrete element method (DEM), the non-linear mechanical model of the wear-resistant body surfaces was established. The step, convexity, and scale arranged structures of the wear-resistant surfaces and their abrasive wear systems were established with the software PFC2D®. Through the qualitative analysis on the morphology, the contact-bond fields and the contact-force chains, the minor injuries and the breakaway of the debris of the wear behaviors are observed. Besides, the dynamic force acted on the wear-resistant structures was studied through the quantitative analysis. Numeral simulation shows that the step structure was worn dramatically in its tip part, the convexity structure distributes the stress prominently and the scale structure shows the best wear-resistant function. The wear loss of the front monomers of the step, convexity, and scale structures are 2.43%, 2.02%, and 1.12% respectively after being worn for eight minutes in the simulation, which are in accordance with the experimental results. The numerical simulation on the abrasive wear behavior of the biological wear-resistant structures by DEM helps to reveal the wearable mechanism of the wear-resistant surfaces. Moreover, it provides a new method for studying the bionic wear-resistant surfaces and structures.

The adhesion and the compressibility of the soft soil will vary as the earth gravity changes. In this study, the pressure-sinkage characteristics in low gravity conditions were investigated by three-dimensional Discrete Element Method (DEM). The data of the DEM parameters were obtained by analyzing the pressure-sinkage relationship embedded in laboratory testing data. The pressure-sinkage experiments of the sample soil in different gravities were simulated by using the software PFC3D. Using the Bekker formula, the values of pressure-sinkage parameters were obtained. The results show that, when the earth gravity changes from one sixth of the standard earth gravity to the standard earth gravity, the sinkage exponent increases lineally. The cohesive module of deformation increases along the conic trend. The low gravities have a sensitive affect on the data of the frictional module of deformation, and the data distribute beside a line. The change laws of the pressure-sinkage parameters provide instructions for the optimization design of vehicles working in low gravity field planet.