When I am using ABAQUS Coupled Eulerian Lagrangian simulation, I meet with a material penetration issue. As in this figure, I set the bottom boundary to fully fixed in Eulerian domain. Then, I would expect that the material will not penetrate this boundary. But certainly there are some material penetrates the boundary in the blue circle.

Anyone has any idea why this penetration occurs that against the sets boundary conditions? And how can I fix it?

Many thanks,