考虑咬合修正系数的自密实砂浆3D-DEM模型

在自密实砂浆的3D离散元模拟(discrete elementmethod,DEM)中,为了准确模拟其摩擦特性,降低单元间相互咬合引起的阻碍作用,该文采用咬合修正系数(engagingfactor,fe)对砂浆单元接触模型进行修正。计算单元接触力时,将与运动方向相反的作用力乘以fe后进行合力的计算。采用自主开发的离散元程序对剪切算例进行数值模拟,验证了fe可有效降低单元间阻碍作用,抗剪摩擦力最大可降低85%以上。对自密实砂浆的摩擦性能进行实验研究并对结果进行模拟,结果表明:通过选取合适的fe和接触参数,模拟结果与实验结果比较吻合。

3D DEM contact modeling of self-compacting mortar with the consideration of the engaging factor

An engaging factor,fe,was developed to quantitatively simulate the friction behavior of self-compacting mortar(SCM) with the 3D discrete element method(DEM) by modifying the DEM contact model for the mortar.When calculating the contact force between elements,each force acting in the opposite direction to the relative velocity is multiplied by the engaging factor to calculate the resultant force.This DEM model can accurately simulate the shear performance of mortar elements by using this engaging factor.The shear resistance force between elements is then reduced by up to 85%.Comparisons with experimental data for the friction behavior of self-compacting mortar show that the mortar friction behavior can be successfully simulated by an appropriate engaging factor and contact parameters.