非均匀颗粒二维动力性状的模拟与研究

通过构造二维离散元模型,分析了土体在动荷载作用下的运动情况,并对任意时间步的应力应变进行了分析。针对以往的单一颗粒的模拟,提出了运用两种不同形状的颗粒进行模拟,即圆盘颗粒和椭圆盘颗粒。并且针对不同泊松比和弹性模量,利用Hertz接触理论,对圆盘圆盘接触、圆盘椭圆盘接触以及圆盘或椭圆盘与四周边界的接触进行了讨论,并对具体接触的法向受力以及颗粒重叠量进行了解析推导。最后通过变化不同动荷载的均值得到σd-εd表示的"骨干曲线",通过对"骨干曲线"的非线性模拟,得到土的动力本构模型。

Simulation and research on two dimensional dynamic properties of non-uniform particles

In this paper, the motion of the soil under dynamic loads is analyzed by constructing a two-dimensional discrete element model, and the stress and strain at any time step are analyzed. The simulation is made by using two different shapes of particles which are the disk particles and the elliptical disc particles, directed against the simulation of single particle in the past.And these two kinds of particles have different Poisson''s ratio and elastic modulus.Using Hertz contact theory, the contact between disc particles, between disc particles and elliptical disk particles and between disk particles or elliptic disk particles and the surrounding boundary are discussed in this paper.The normal stress and the particle overlap of the specific contact are deduced.Finally, by changing the mean value of different dynamic loads, the "backbone curve" is obtained, and the dynamic constitutive model of soil can be obtained by the nonlinear simulation of the "backbone curve".