波纹表面接触土壤颗粒动态响应仿真分析

Simulation on Dynamic Behavior of Soil Particle Contact with Wavy Surface

为揭示波纹表面的降阻机制,以蚯蚓体表为研究对象,应用离散单元法对接触土壤颗粒动态响应进行仿真分析。仿真得出:波纹表面接触的土壤颗粒运动过程微观可分为'分散—团聚—分散'3个阶段,宏观表现为土壤与波纹试样之间形成孔隙;波纹表面接触颗粒的X向位移与试样的前进方向一致,呈线性增加,平均位移为60.33 mm,Y向速度随着波纹表面的凹凸起伏呈正弦变化、产生微震,且大于光滑表面接触颗粒振幅,波纹表面接触颗粒和波纹的接触位置直接决定受力的大小和方向。分析表明:波纹表面接触颗粒的运动幅度和频率大于光滑表面,颗粒产生微震,且波纹表面与土壤间存在孔隙,从而使得接触面积减小、阻力降低。

The earthworm＇s surface was selected as the object to study the mechanism of resistance reduction of wavy surface, and discrete element method （DEM） was used to simulate the dynamic response of the contact soil particle with wavy surface. The results of simulation showed that the contact time was shorter when the particle contacted with wavy surface, and the particle separated at 1.0 s. Macroscopic showed that the porosity was formed between the wavy sample and soil particle. X direction displacement of the contact particle was increased linearly and in the same direction, the average displacement was 60.33 mm. Y direction velocity was changed with the concave-convex of the wavy surface like sinusoidal variation, and generated microseism, the amplitude of the wavy surface was bigger than the smooth surface~ Contact position directly determined the size and direction of the contact force. Analysis showed that the amplitude and frequency of the contact particle with wavy surface was greater than smooth surface. The results can supply the reference to design the bionic wavy surface.