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 survey shows that the bulk density of lunar soil increases with the depth. The compaction of lunar soil also differs in the depth. The lunar soil mechanical condition plays an important and non-negligible roll on the mobility of the rover. It is important to make research on the change of the mechanical parameters at different lunar soil conditions, and it is also important to research the trafficability of rover on different lunar surface condition. The presented paper simulates the lunar soil with different depth by means of three kinds of lunar soil simulant on different compact condition. Based on the direct shear apparatus, it was researched that the cohesion, internal friction angle, bull density of lunar soil simulant on different compaction conditions, including loose, normal, and compressed. The measurement results show that the bulk density and cohesion of the lunar soil simulant increase with the compact conditions in general. The bulk density changes within a narrow range from1.1 g/cm3 to 1.4 g/cm3. The cohesion increases, and changes significantly, which varies from 0 kPa to 0.5 kPa. The internal friction angle changes without regularity within a range from 30 deg to 40 deg. The measurement results can be used to explain the different trafficability of wheels after repeatedly passing the same lunar surface. Also it will be of significant to the evaluation of the rover mobility at different lunar soil condition.