  In recent paper (Goloveshkin and Myagkov 2014) we proposed a two-dimensional
energy-based model of fragmentation of rapidly expanding cylinder under plane
strain conditions. The model allowed one to estimate the average fragment
length and the number of fragments produced by ductile fracture of the
cylinder. In present note we show that the proposed approach can be used to
estimate the number of fragments in a problem of fragmentation of an expanding
ring.
