야지노면에서의 바퀴 주행 해석을 위한 DEM 토양 모델링

A numerical analysis using discrete element method (DEM) was conducted to estimate of soil parameters required for a wheel driving force prediction over loose soil. Two types of DEM models are described in the present paper; a triaxial compression model for determination of bulk soil material properties and a single rigid wheel traversing model to investigate effects of the soil parameters on traversability. The triaxial compression model calibrates local contact parameters between particles, such as Young’s modulus, dynamic friction coefficient, rolling friction coefficient, damping coefficient, adhesion and etc., to adjust the bulk soil material properties like internal friction angle and shear strength. Also parametric studies were conducted to investigate effects of friction coefficients and adhesion between particles on the internal friction angle and the shear strength. On the other hand, the wheel traversing model shows the relationship between the bulk soil material properties estimated by the triazial compression model and traversability indicated by wheel slip, sinkage and drawbar pull. This study gives a simple and efficient way to build the wheel-soil model of unknown terrain with the bulk soil material properties driven by DEM model.