月壤静力学特性的离散元模拟

Statics characteristics of lunar soil by DEM simulation

以典型月壤的物理力学性质为参照标准,采用颗粒流程序PFC3D对月壤静力学特性进行了离散元模拟研究。通过离散元模拟三轴试验反复调整颗粒细观参数,建立了月壤离散元接触力学模型;描述了月面探测车辆行驶下的月壤承压特性模型与剪切特性模型;从月面探测车辆的行驶观点出发,模拟压板试验,得出了载荷-沉降关系;通过模拟履带板试验得出了剪切应力-位移关系。最后,计算出了月壤的变形模量K为1635 kN/mn+2、变形指数n为1.22,剪切变形模量k为1.35 cm。结果表明,模拟试验值与模型预测趋势一致。

According tO its physical mechanics properties, the statics characteristic of lunar soil is studied using DEM software PFC3D. The DEM contacting mechanics model of lunar soil was built by triax-test to adjust the particle micro parameters. The pressure-sinkage model and shear model of the lunar rover passing on lunar surface were described. Then the plate-sinkage-test was simulated to obtain the relationship between load and sinkage; and the shear-test was simulated to obtain the relationship between shear and displacement. Finally the terra-mechanics parameters of the lunar soil were calculated as： the deformation modulus K=1635 kN/m^n＋2 , the sinkage exponent n= 1.22 and the shearing strength displacement modulus k= 1.35 cm. These values obtained by DEM simulation are close to that obtained by prediction model.