Hi Shantanu,
you may want to try LIGGGHTS, www.liggghts.com. It is basically LAMMPS with re-writes and add-ons for granular (DEM) simulations.
In LIGGGHTS, you can define material properties such as Young’s modulus and Poisson’s ratio for each atom type and coefficients of friction and restitution for each pair of atom types. Stiffness an damp coefficients are then calculated from these properties.
Christoph