System and method for rheological characterization of granular materials

摘要

A system for characterizing rheological properties of granular material. A cylindrical measurement cup containing granular material is subject to a uniform vibration induced by a vibration exciter at a user-determined frequency. At the same time, a rotation or an oscillation of a rotating vane tool is performed within the powder and a response measured. Baffles are affixed to the inner wall of the measurement cup to prevent slippage of the granular material during measurement. An energy imparted to the system from the vibration exciter can be measured by an accelerometer coupled to the measurement cup. When sufficient vibrational energy is supplied to the system, a powder contained therein achieves a particle "temperature" sufficient such that the powder behaves as an ergodic system. The visco-elastic properties of the ergodic powder can be reproducibly measured in accordance with known methodology used in molecular fluids, where the powder "temperature" can be varied by changing the vibration frequency or amplitude.