A discussion on ideal and nonideal systems

Resumo

In this paper we discuss the nature of the so called ideal and non-ideal models for a two-degree-of-
freedom unbalanced motor foundation. In the latter model, the mutual interaction between the machine and the

foundation is taken into account, while in the former only the action of the motor on the foundation is considered.
In the non-ideal system, for limited power conditions, the so-called Sommerfeld Effect may occur, of stagnation
of rotation frequency before resonance peaks. If mode energy is available to overcome this situation, a jump occurs
to considerably higher frequency rotation regimes, no intermediate stable steady states in between.