Discrete Hertzian chains and solitons

We consider elastic grains which repel upon contact according to the Hertz potential V=aδn, n>2, where δ is the overlap between adjacent grains and report numerical and analytical studies for the case of a 1-D chain of spherical grains to show that an impulse initiated at an end of a chain of Hertzian grains in contact, eventually propagates as a soliton for all n>2.