不同粗糙度平面上静止颗粒堆底的切应力分布

Tangential stress distribution at the bottom of a static granular pile on the planes of different roughness

在两种不同粗糙底面上测量了用从固定点以相同流量落下颗粒的方法制备而成的圆锥堆底的切向应力分布.结果显示,粗糙度大的底面有相对较大的切向应力.利用一般的力平衡方程、库仑不等式、圆锥堆侧面的自由边界条件以及测量的数据可以验证,堆底面切向应力强度与法向应力分布出现中心凹陷现象有关,切向应力越大凹陷现象越明显.另外,提出了一个颗粒堆的非线性应力关系唯象模型.

We measured the distribution of tangential stress on bottom of conic piles, formed by pouring granular materials from a fixed point with a same flux, on two planes of different roughness. The results show that the stress depends on the plane roughness and the rougher one has the stronger stress. Using the general equations of force balance, Coulomb inequality, free boundary conditions for side surfaces of the piles, and the measured data, it could be shown that the strength of tangential stress are related with dip observed in distribution of normal stress. Namely a stronger tangential stress has a more notable dip. Finally we proposed a nonlinear phenomenological model of stress relation for granular piles.