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BP: Fachverband Biologische Physik
BP 16: Poster - Glasses / Stat. Phys. Bio. / Networks (joint DY/BP/CPP/SOE)
BP 16.5: Poster
Dienstag, 1. April 2014, 09:30–12:30, P1
Mechanical Properties of Sheared Wet Granular Piles — •Somnath Karmakar1, Marc Schaber1, Anna-Lena Hippler1, Martin Brinkmann2, Mario Scheel3, Marco Di Michiel3, and Ralf Seemann1,2 — 1Experimental Physics, Saarland University, Saarbrücken, Germany — 2MPI for Dynamics and Self-Organization, Göttingen, Germany — 3European Synchrotron Radiation Facility, Grenoble, France
Adding small amount of wetting fluid to dry granulates typically leads to the granular stiffness which arises due the formation of minute liquid contacts between individual granules by the virtue of capillary forces. We experimentally study the mechanical properties of wet granulates, composed of monodisperse spherical glass or basalt beads. The glass microspheres are almost perfectly wetted by water whereas the basalt microspheres have a rather large contact angles with water. The different wettability causes a difference in the shape and volume distribution of the appeared liquid morphologies. We have investigated the shear strength, measured under cyclic shear deformation for various system parameters like liquid content, shear rate and absolute pressure. At large absolute pressures, the associated energy dissipation of a sheared wet granulate is considerably smaller than that of a completely dry bead assembly; where the wetting fluid might act as a 'liquid lubricant' by lowering the wet bead pile's shear stiffness. With time resolved X-ray microtomography, we could shed some light on the underlying microscopic mechanisms of the sheared wet granulates.