Non-linear dynamics versus chaotic motion for MDOF structural systems

The evaluation of chaotic phenomena can be related either with the dynamical aspects of the motion (as in the assessment of the Lyapunov exponents and of the Kolmogorov entropy) or with its geometrical appearance in the phase space (as in the computation of the attractor dimension). Both these estimates are not satisfactorily reliable in a numerical context. Nevertheless, in engineering applications the goal is just to detect the regions of chaotic behaviour in the system parameter space. Even a rough delimitation of these regions can make it possible that the dynamical behaviour of a structure avoids showing unpredictable aspects or sensitivity to the initial conditions. This paper pursues the definition of the chaotic regions of an MDOF system by a parametric analysis in its embedding space.