Berlin 2015 – scientific programme
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DY: Fachverband Dynamik und Statistische Physik
DY 62: Poster - Dynamics
DY 62.17: Poster
Thursday, March 19, 2015, 16:00–18:00, Poster A
3D contact force measurement in a granular packing — •Junaid Masud 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, the physics is expected to be different inside 3D granular packings.
Towards this end, we have implemented a two photon spectroscopy technique, by harnessing the pressure dependent fluorescence property of ruby [3]. The technical challenges, introduced by the high refractive index (RI ~ 1.76) of ruby, are solved by designing a high numerical aperture (NA~1.4) objective lens and finding a RI matched light scattering free immersion liquid solution. The first proof of concept experimental results 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)