基于SPH算法的平面刀土壤切削过程模拟

以我国华北一年两熟区保护性耕作地土壤为原型,利用ANSYS/LS_DYNA对平面刀切削土壤过程进行数值模拟,并通过理论分析和试验,验证SPH算法在模拟平面刀切削土壤过程方面的可行性。结合MAT147土壤材料模型,SPH算法及点-面侵蚀接触,运用ANSYS/LS_DYNA软件对平面刀切削土壤过程进行有限元分析。仿真结果表明,SPH算法能够直观模拟平面刀切削土壤整个过程,最大等效应力为5.851 MPa,主要集中在与平面刀接触的土壤上;平面刀切削全过程表明,土壤所受等效应力波动较小,切削过程比较平稳;稳定切削时切削功耗在10.2 kW附近波动,通过理论和试验验证,仿真切削误差不大于0.05。由此说明SPH算法进行平面刀切削过程的数值模拟是可行的。

Simulation of Soil Cutting Process by Plane Blade Based on SPH Method

This paper numerically simulated the soil cutting process of plane blade, one of the important components in no-till working implement, by ANSYS/LS_DYNA, with soil of conservation tillage in one year two crops area of North China. By theoretical analysis and test, the viability of SPH method on simulating the soil cutting process of plane blade was verified. By using MAT147 soil material model, SPH method and nodes-surface eroding contact, the finite element analysis on the soil cutting process of plane blade was implemented by ANSYS/LS_DYNA. Simulation result showed that SPH method could visually simulate the soil cutting process. The maximum Von Mises stress was 5.851MPa and focused on the soil touching with plane blade. The Von Mises stress of soil had small fluctuation, so that the cutting was stable. The power consumption was approximately 10.2kW at steady state, and the simulation error was not more than 0.05. It was proved that SPH method was viable, and finite element simulation could obtain parameters easily, such as scatter feature, force and power consumption, and reduce experimental cost and time. It provided a scientific basis for design optimization of conservation tillage anti-blocking implements.