Granular materials consist of a large number of
discrete macroscopic particles interacting with each other via contact forces.
They exhibit behavior similar to solids, liquids and gases in
different situations. Although simple in their composition, the wide
range of unusual phenomena exhibited by them is predominantly the
result of highly dissipative and nonlinear contact forces.
Measurement of these contact forces would therefore be highly useful
even in static situations. I intend to describe one such method we have
developed for a model granular system composed of photo-elastic
disks. The method consists of extracting contact forces by fitting
experimental images to a theoretical model. Distributions of normal
and tangential forces are obtained for a simple sheared system with the
use of this method.I will also describe ongoing and future projects.