Analysis Of Tractive Performance For Wheel On Sandy Road Using Discrete Element Method

In recent years, Chinese Lunar Exploration Project has made significant progress and Jade Rabbit had landed on the moon successfully; on the other hand, the desert region in northwest of our country is rich in oil resources and heavy-duty vehicles is yet to be developed; meanwhile, China now is making great effort to develop marine resources and naval forces is carrying out landing traninng frequently, thus high speed landing equipment need to be solved. Lunar siol, desert and sands are typical sandy road conditions, so the research on the wheel-terrain interaction is significant for politics, economy and military.The wheel-terrain interaction problem belongs to Terramechanics. Based on the theory of Terramechanics and Discrete Element Method(DEM), this paper studied the dynamic simulation of wheel-terrain interaction on sandy road in the microscopic point. The main contents and results of this paper are listed as follows:1. Various indexs were introduced to describe soil's physical characteristic and mechanical property, also the Bekker's press-sinkage model and Janosi's shear model. A mechanic model of the rigid rolling wheel on sandy road was constructed.2. A brief introduction of DEM and PFC3 D was made and the author carried out simulated triaxial compression test using FISH in PFC3 D to calibrate the basic microscopic properties of model based on lunar soil stimulant.3. A soil bin model and a “CLUMP” rigid wheel model were built and a 3D system of soil bin was built based on the basic microscopic properties. A simulation test of wheel tractive performance was made and got some test results. The system has got verified from the simulated pressure plate test and compared with the indoor soil bin test.4. The paper studied the influence of coefficient-slip, wheel configuration parameters and shape of soil particle to the tractive performance for wheel. The results showed that keep coefficient-slip at 50% were useful and increase the wheel diameter or width and shape difference can improve the tractive performance.