基于FEM/DEM的轮胎-沙地相互作用的仿真

Simulation of Tire-Sand Interactions Based on FEM/DEM

介绍了离散元与有限元耦合方法(FEM/DEM)的基本原理,提出了对应轮胎-沙地接触计算的Slave区域自适应定义方法.基于室内土槽实验,建立了轮胎-沙地相互作用的三维仿真模型(不考虑轮胎变形),其中,沙地使用球形离散单元(DE)模拟,土槽、轮胎使用六面体有限单元(FE)描述.然后,采用基于FEM/DEM的自主开发软件CDFP对光面和人字形沟槽两种胎面结构轮胎在沙地的行驶行为进行仿真,通过光面轮胎仿真结果与相应实验结果的对比,验证了该方法的可行性和有效性.对比两种胎面结构轮胎的仿真结果(法向反作用力、挂钩牵引力等),解释了越野轮胎开凿沟槽的必要性.

In this paper, the basis of the combined finite and discrete element method （ FEM/DEM ） is intro-duced, and an adaptive Slave region method is proposed according to the FEM/DEM simulation of tire-sand interac-tions.Moreover, the three-dimension simulation models of tires running on sand are constructed based on a soil bin experiment with the tire deformation being neglected, where the sand is modeled by using spherical discrete ele-ments, the soil bin and the tires are discretized into hexahedron finite elements.Then, the running behaviors of the smooth and groove tires on sand at different slip ratios are simulated by using the self-developed software CDFP, which is an explicit combined discrete-finite element program.The simulation results of the smooth tire are com-pared with the corresponding experimental ones, thus verifying the feasibility and effectiveness of the proposed method.In addition, the comparison of the simulation results （ such as road reaction force and tire drawbar pull） of the smooth and groove tires explains the necessity of the grooves of off-road vehicle tires.