非规则泥沙颗粒流动堆积过程中接触模型参数研究

Study on parameters of contact model for non-uniform gravel particles in movement and accumulation processes

采用离散元法研究颗粒的流动与堆积过程时,物性参数和接触参数的选择是否合理直接影响着模拟结果的准确性。对于非规则颗粒而言,这些参数的选取尤为重要。以非规则泥沙颗粒为例,根据其形状和大小的不同建立了四种颗粒模型。设计了一系列试验来标定泥沙颗粒的密度、恢复系数、静摩擦系数、内摩擦系数,并通过试验与模拟相结合的方法标定了颗粒间滚动摩擦系数。通过试验和离散元仿真的手段对比了顶层泥沙在V型箱和L型箱中的流动过程,结果表明试验与仿真得到的运动轨迹吻合,验证了所采用的测定物料参数和接触参数方法的可行性和参数选择的合理性。

Discrete element method（ DEM） is used to simulate the flow and accumulation processes of the particles.The accuracy of the simulation results is directly influenced by the choice of physical parameters and contact parameters.Four kinds of irregular particle models are established according to their shape and size in this paper.A series of experiments were designed to calibrate the density,recovery coefficient,static friction coefficient and internal friction coefficient of the gravel particles.Friction coefficient between the particles is also determined by the combination of experiment and simulation.Flow processes of the top layer particle in V shape box and L shape box are compared by means of experiment and DEM simulation.It is shown that the trajectory of the top layer particle in DEM simulation coincides well with the experiment trajectory.