Influence of flow velocity variability on pipeline stability boundaries

The parametric oscillations of a classical system under nonconservative loading — a flexible pipeline with a flowing liquid — are considered. The parametric effect on the system is determined by the variability of the fluid flow rate. The stability of the rectilinear form of the pipeline equilibrium according to the Floquet–Lyapunov theory is investigated by the method of monodromy matrices. Under the assumption of a harmonic deviation of the flow velocity from a certain constant value, in particular, the amplitude and frequency, the main attention is paid to the study of the influence of the characteristics of the parametric influence on the position of the stability boundary of the rectilinear form of the pipeline equilibrium.