  We show that a model proposed by Rubin, Rosenau, and Gottlieb [J. Appl. Phys.
77 (1995) 4054], for dispersion caused by an inherent material characteristic
length, belongs to the class of simple materials. Therefore, it is possible to
generalize the idea of Rubin, Rosenau, and Gottlieb to include a wide range of
material models, from nonlinear elasticity to turbulence. Using this insight,
we are able to fine-tune nonlinear and dispersive effects in the theory of
nonlinear elasticity in order to generate pulse solitary waves and also bulk
travelling waves with compact support.
