INVESTIGATION OF STABILITY ON NONLINEAR OSCILATIONS
WITH ONE DEGREE OF FREEDOM
Julka Knezevic-Miljanovic1 and Ljubica
Lalovic2
1Mathematics faculty of Belgrade, Serbia and Montenegro
2Faculty of Mechanical Engineering of Kraljevo, Serbia and
Montenegro
(Received May 15, 2003)
Abstract. This paper
presents a phase portrait of differential equation of vehicle
vertical oscillations when establishing force in springs is
changed under nonlinear laws:
Fc=c(x+ax2)and
Fc=c(x+ax3), c > 0, a ¹ 0.
Analysis of nonlinear oscillation stability has been done using
the phase portrait analyses.