Dynamics of a time delayed Duffing oscillator

This paper focuses on the primary resonance of the time delayed Duffing oscillator solved by means of the multiple scales method. The second order approximation is used because the first approximation applied in the literature does not exhibit specific phenomena of the studied system. The Duffing system is investigated in two aspects. First of all, how delay displacement feedback influences the primary resonance of the classical Duffing oscillator in order to control the system and, on the other hand, how the external harmonic force influences vibrations of the system with time delay which is essential in applications, e.g. in machining. Stability of solutions and their bifurcations caused by the system parameters are shown. Especially, coexistence of possible stable and unstable solutions is investigated versus time delay and external excitation parameters. The selected analytical results are compared with numerical simulations. The model presented in the paper is considered as a general problem of non-linear oscillator with time delay but specific attention is paid to cutting process control.