Department of Mathematics, College of Sciences, Hohai University, Nanjing 210098, China
Copyright © 2010 Jifeng Chu and Ting Xia. This is an open access article distributed under the
Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Let be continuous -periodic functions with . We establish one stability criterion for the linear damped oscillator . Moreover, based on the computation of the corresponding Birkhoff normal forms, we present a sufficient condition for the stability of the equilibrium of the nonlinear damped oscillator , where is a continuous -periodic function, is continuous -periodic in and dominated by the power in a neighborhood of .