New phenomena associated with the nonlinear dynamics and stability of autonomous damped systems under various types of loading

The present study deals with the nonlinear dynamics and stability of autono mous dissipative either imperfect potential (limit point) systems or perfec t (bifurcational) non-potential ones. Through a fully nonlinear dynamic ana lysis, performed on two simple 2-DOF models corresponding to the classes of systems mentioned above, and with the aid of basic definitions of the theo ry of nonlinear dynamical systems, new important phenomena are revealed. Fo r the first class of systems a third possibility of postbuckling dynamic re sponse is offered, associated with a point attractor on the prebuckling pri mary path, while for the second one the new findings are chaos-like (most l ikely chaotic) motions, consecutive regions of point and periodic attractor s, series of global bifurcations and point attractor response of always exi sting complementary equilibrium configurations, regardless of the value of the nonconservativeness parameter.