Fiber reinforcement on spherical granular beds under triaxial compressions

In this study, triaxial compressions of spherical granular beds that are reinforced by immersed flexible fibers, are simulated using the discrete element method (DEM). The DEM model is calibrated for the simulation studies of flexible fiber reinforced granular beds according to the agreement between experimental and simulation results. It is found that yield stresses of the particle beds increase as fiber concentration or its aspect ratio increases, while the yield stresses are insensitive to fiber flexibility. Configuration of the immersed fibers has a remarkable impact on compressive strength of the beds. Compared to the case with randomly distributed fibers, a vertically-placed fiber bundle augments the maximum yield stresses while exhibits negligible effect on residual stresses. Placing the fibers in a cage or net structure can dramatically enhance the strength of the particle beds, depending on the distances between the individual fibers.