推土板表面形态对土壤动态行为影响的离散元模拟

土壤行为的变化过程直接受触土部件结构的影响，研究不同表面推土板作用下土壤动态行为的变化规律和影响因素对于触土部件的优化设计具有重要意义。根据液桥对土壤微观力学结构的影响，在传统离散单元法理论的基础上，建立了土壤颗粒接触非线性力学模型，并对光滑和波纹形表面形态推土板前端土壤的动态行为进行了离散元模拟。结果表明：离散元模拟不仅准确再现了实验中表面形态对板面前端土壤动态行为影响的定性和定量结果，而且通过离散元细观分析从土壤内部土壤颗粒运动合理解释了土壤宏观形态的变化规律以及推土板表面形态对土壤动态行为的影响，即波纹形表面使板面前端土壤波动频率变大，而波动幅度变小。该研究为土壤－机械相互作用分析提供了新的研究思路和手段。

Simulation of dynamic behavior of soil ahead of the bulldozing plates with different surface configurations by discrete element method

The changing process of soil behaviors is influenced by structure of soil-touching parts directly. Therefore, research on the variation laws and the influenced factors of dynamic behaviors of soil, subjected by a bulldozing plate with different surfaces, is very important for the optimized design of soil-touching parts. The nonlinear mechanical model of contact between soil particles was established based on the effects of liquid bridges on mechanical microstructure of soil and the basic Distinct Element Method(DEM) theory. The dynamic behaviors of soil ahead of the bulldozing plates with smooth and wavy surfaces were simulated by DEM from macroscopic and mesocopic aspects. Results indicate that the DEM simulations reappear the qualitative and the quantitative results by laboratory test accurately, moreover, the mesocopic analyses by DEM explain the variation laws of dynamic macroscopic behaviors of soil through soil particles motion in soil body, and open up the influencing factors on these behaviors resulted from the surface configurations of the bulldozing plate, namely, the wavy frequency of dry soil ahead the plate with wavy surface becomes larger, but the wavy range of these dry soil becomes smaller. These studies provide new research ideas and methods for analysis in soil-tool interaction.