Development of a FE-DEM analysis with element transfer function and its application to contact problems in terramechanics

离散单元法是分析越野车辆行走装置或工作工具与越野地面接触问题的一种数值方法。然而，由于离散元法是建立在对分析中的所有元素进行接触判断和接触反力计算的基础上的，因此，利用真实的土颗粒单元进行离散元法分析还没有实现。为了实现上述接触分析，我们的小组已经提出了一种方法，如FE-DEM分析。本文提出了一种在离散元和有限元之间转换单元的新思想，以减少接触区周围所需离散元的总数。以农用轮胎牵引性能为例进行了有限元离散元法分析。分析结果表明，计算时间可以减少到约29倍小于传统的FE-DEM具有足够的精度。

The discrete element method (DEM) has become popular as a numerical tool to analyze the contact problems between off-road terrain and running devices or working tools of off-road vehicles. However, DEM analysis using the elements of real soil particles has not yet been realized, since DEM is based on the computation of contact judgment and contact reaction for all elements in the analysis. To realize the above-mentioned contact analysis, an approach such as FE-DEM analysis has been proposed by our group. In this study, a new idea of transferring elements between DEM and FEM is proposed so that the total number of necessary DEM elements around contact area can be reduced. A simple example of traction performance analysis of an agricultural tire was demonstrated by FE-DEM with the proposed element transfer function. The result of the analysis showed that the elapsed time of computation could be reduced to about 29 times smaller than the conventional FE-DEM with sufficient accuracy.