Dresden 2014 – scientific programme
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DY: Fachverband Dynamik und Statistische Physik
DY 41: Poster - Pattern/ Nonlinear Dyn./ Fluids/ Granular/ Critical Phen.
DY 41.30: Poster
Thursday, April 3, 2014, 17:00–19:00, P3
Measuring contact forces in 3D inside granular packing — •Junaid M. Laskar1, Stephan Herminghaus1, Matthias Schröter1, and Karen E. Daniels2 — 1Dynamics of Complex Fluids, Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany — 2Department of Physics, North Carolina State University, Raleigh, USA
Knowing the contact forces and their statistical distributions inside a granular packing is a central question in granular physics. Measurement of contact force distributions and force chains till now have been possible only in 2D [1,2]. However, measurement inside a 3D granular packing, where the physics is expected to be different, still remains an experimental challenge.
An intrinsic property of ruby is linear change of its fluorescence signal as a function of applied stress [3]. By making use of this property, an experimental technique is developed to measure contact forces inside the packing of ruby spheres. The results obtained by this technique, which is based on aplanatic solid immersion lens optics and two photon fluorescence spectroscopy, will be discussed.
References: [1] T. S. Majumdar and R. P. Behringer, Nature 453, 1079 (2005) [2] Karen E. Daniels and Nicholas W. Hayman, J. of Geophys. Res. 113, B11411 (2008) [3] Y. Chen et al., J. Appl. Phys. 101, 084908 (2007)