Analysis of a forced strongly non-linear two-degree-of-freedom system by means of the power-series method

A power-series solution is presented for the periodic motion of an undamped strongly non-linear two-degree-of-freedom system excited by harmonic force s. The analysis is facilitated by transforming the time variable into an ha rmonically oscillating time. The frequency of the new time variable is dete rmined by observing the equality between the rate of change of dynamical en ergy and the power delivered by the forces. The results show good agreement with the modified Lindstedt-Poincare method and the incremental harmonic b alance method. (C) 2001 Academic Press.