LOCALIZATION OF THE ATTRACTORS OF THE NONAUTONOMOUS LIENARD EQUATION BY THE METHOD OF DISCONTINUOUS COMPARISON SYSTEMS

The construction of simple discontinuous comparison systems with non-l inear elements of the ''dry friction'' type is proposed. The sets of c losed trajectories of such systems, which are contact-free with respec t to the vector field of the initial system, enable one to obtain esti mates of the dissipation domain simply. A similar approach is also use d to construct annular domains. The absence of the property of converg ence in the case of a Lienard system with a periodic additive term fol lows from the existence of these domains. (C) 1996 Elsevier Science Lt d.