Effect of Wheel Surface Curvature Radius on Sinkage Performance of Sand Rigid Wheel

Abstract:

It is important that wheel surface curvature radius has an influence on the sinkage performance of rigid wheel in sandy environment. Based on wheel surface pressuresinkage experiment, dynamic experiment of soil bin bench and discrete element numerical simulation, the sinkage performance of rigid wheel moving on sand of flat, concave (wheel surface curvature radius was 80mm, 120mm, and 60mm) and convex (wheel surface curvature radius was 80mm and 120mm) surface of six different wheel surface curvature radii in three different shape and size sand particles (coarse diameter quartz sand, fine diameter quartz sand and dust volcanic ash) were analyzed. The pressuresinkage experiment showed that compared with other rigid wheel of different wheel surface curvature radius, the sinkage of rigid wheel with flat surface was the smallest on fine diameter quartz and dust volcanic ash. Compared with other sand medium, the sinkage of all wheels with flat, concave and convex surface were the smallest of all on coarse diameter quartz sand. Numerical simulation of wheel surface pressuresinkage showed that the force field distribution of sand particle under flat surface wheel was homogeneous and overflowed particles were small. Dynamic experiment of soil bin bench showed that the sinkage of concave R80 wheel was the smallest at the beginning of travelling period (the displacements were less than 50cm), then the sinkage of concave R60 wheel was the smallest at the travelling steady state (the displacements were larger than 70cm). On the dust volcanic ash, within the scope of the whole movement, the sinkage of concave R60 wheel was the smallest of all. Therefore, on the fine diameter quartz and dust volcanic ash, the larger wheel surface curvature radius of concave surface wheel, the better antisubsidence performance. In addition, dynamic discrete element simulation on fine diameter quartz sand demonstrated that stress area of concave wheel was focused on both sides of the wheel and concave structure could have an effective effect on preventing sand in lateral flowing and reducing the disturbance of sand. This research not only provided the reference frame for estimating the sinkage performance of wheels with different wheel surface curvature radius on different sand media, but also provided the vital theoretical basis for the design of wheel/tire wheel surface structure of desert or deep space exploration vehicle.