颗粒滚动摩擦系数对堆积特性的影响

为探讨颗粒摩擦系数对堆积特性的影响,利用离散单元法,模拟静摩擦系数固定时,变化滚动摩擦系数对椭球形颗粒堆积角及堆积体的影响.利用自制斜面仪测定了颗粒静摩擦系数,并对滚动摩擦系数与堆积角建立线性方程.结果表明,滚动摩擦系数对颗粒堆积特性有显著影响,颗粒堆积角随滚动摩擦系数增大而增大,边界圆与连续圆间的间隙随滚动摩擦系数增大而减小.依据颗粒堆积过程中旋转动能的变化可以阐述上述结果,建立的滚动摩擦系数与堆积角的线性方程可为具体颗粒物料滚动摩擦系数的获取提供数值测量思路.模拟堆积的过程可为散体物料一些不易测量的参数进行虚拟实验标定.

Influence of granular co efficient of rolling friction on accumulation characteristics

The influence of friction coefficient, in terms of fixed static friction coefficient (sfc) and different rolling friction coefficients (rfc), on the accumulation characteristics of particle, including the angle of repose and accumulation body, is simulated using the discrete element method. The sfc of a particle is measured with a home-made cant instrument, and a linear equation is developed to describe the relationship between the rfc and the angle of repose. Results show that rfc has obviously an influence on the accumulation characteristics of particles: the angle of repose of particles increases as rfc increases, the gap between the boundary circle and the continuous circle decreases with increasing rfc. Based on the change of rotational kinetic energy in the process of accumulation of particles, the above results can be explained. And the linear equation can provide ideas for numerical measure of granular rfc. For some difficultly measured parameters of bulk materials, the simulation of accumulation process is a valid virtual calibration test.
Keywords： coefficient of rolling friction particle accumulation discrete element simulation