A method for obtaining approximate analytic periods for a class of nonlinear oscillators

This paper deals with nonlinear oscillations of conservative single-degree- of-freedom systems with odd nonlinearity. By combining the linearization of the governing equation with the method of harmonic balance, we establish t wo approximate analytic formulas for the period. These two formulas are val id for small as well as large amplitudes of oscillation. Three examples are used to illustrate that the proposed formulas can give very satisfactory a pproximate results.