An exponential stability criterion for nonlinear second-order functional differential equations with time-variable delays

This paper is concerned with the exponential stability for nonlinear second-order functional differential equations (FDEs) with time-variable delays. An exponential stability relationship between the FDEs and the corresponding ordinary differential equations (ODEs) is derived. It is proved under some appropriate conditions that the second-order FDEs can preserve the exponential stability of the corresponding ODEs. This stability result is also illustrated with a numerical approach.