Non-linear vibration of coupled Duffing oscillators by an improved incremental harmonic balance method

Abstract

The incremental harmonic balance method is improved by (i) reversing the order of increment and linearization to find the bifurcated solution branches, (ii) using a fast Fourier transform to compute the solution increments and the Floquet matrix, and (iii) finding the secondary path after a bifurcation by an improved arc-length method. A system of two Duffing oscillators linked with a linear stiffness is taken as a numerical example. The qualitative change of solution due to the change of the linking stiffness is studied in detail.