BIFURCATION AND CHAOS OF ALT –TANKER WITH SQUARE DAMPING AND PIECEWISE LINEAR STIFFNESS

The bifurcation and chaos of ALT (Articulated loading tower)-Tanker system under regular excitation are studied. The system is simplified into single degree of freedom dynamics model with piecewise linear restoring forces and square damping, then the piecewise nonlinear motion equation of ALT is established. The steady periodic solution of ALT is obtained by incremental harmonic balance (IHB) method. The stability analysis is performed by using Floquet theory. The path-following procedure using the incremental arc length method is used to trace response curves and the road of entering into chaos. The system exhibits two kinds of chaotic motion through a sequence of period doubling bifurcations. The max Lyapunov exponent diagrams of two kinds of chaotic motion from beginning to vanishing are obtained for validating chaotic motion of the system.