ABSTRACT
Introduction Reduction of the Biharmonic Dynamics System to the Duffi ng Equation As is well-Known, a nonlinear system can perform a chaotic motion under the action of periodic forces [1-4]. Frequently the Duffi ng equation is used to illustrate chaos [1-4], and the chaotic behavior of various forms of the Duffi ng equation [5], some of which exhibit two-frequency excitation [6] as well as the chaotic motion of Duffi ng system with bounded noise [7] have been investigated. However the Duffi ng equation in the expanded (generalized) form has many mechanical applications and it can be interesting to researchers.
