Spectral analysis of nonlinear systems

Abstract

Two separate nonlinear differential systems are investigated in the frequency and time domains using plots generated by Mathematica. Spectral density plots are of particular interest as they can conveniently demonstrate the effect on a system of changing one of the parameters. The effects of the starting displacement on the nonlinear pendulum, and the behavior of the Lorenz system when the Rayleigh number is varied, are considered in this way.Proucena su dva razdvojena nelinearna diferencijalna sistema u frekventnom i vremenskom domenu koriscenjem crteza generisanih kodom Mathematica. Crtezi spektralne gustine su posebno interesantni jer mogu da podesno pokazu efekat promene jednog od parametara sistema. Na ovaj nacin su posmatrani uticaji pocetnog pomeranja na nelinearno klatno kao i ponasanje Lorencovog sistema pri promeni Rejlijevog broja.