Quartz grain crushing

Here, we propose a simple example made with eight round grains (fig.1). This aggregate is subject to uniaxial vertical loading applied through constant forces acting on the two bounding platens. In the second principal direction (perpendicular to the loading and horizontal on the sketch), the grains are free (i.e. they can move as much as necessary to accommodate the compression without breaking). An iterative procedure allows us to present the space evolution of each grain and its internal stress field evolution (see animation). This indicates that the stress field is not constant and evolves with time in respect to grain contact number and the geometry of those contacts. The maximum stress difference is located along the grain contact lines. The magnitude of stress difference is not identical for all contact lines and for all grains. Contact lines more closely aligned with the loading direction seem to show a higher stress difference.