一类二阶非线性方程周期解的存在性

Existence of Periodic Solutions for a Class of Second Order Nonlinear Equations

研究了二阶非线性滞后型微分方程x¨(t)+P[x.(t)]+Q(x.(t),x(t-τ))=f(t)。通过Lyaponov方法给出了周期解存在性定理,推广了一些已知结果。

The second order nonlinear retarded differential equation x（t）＋P[x（t）]＋Q（x（t）,x（t-τ））=f（t）is considered. A theorem on existence of periodic solutions is given by means of the Lyapunov＇s method. This obtained result generalizes some known results.