Influence of longitudinal force and internal pressure on the frequency of free vibrations of an underground oil pipeline

Abstract

This paper is based on the equation obtained earlier by V.G. Sokolov to find the frequencies of natural vibrations of straight sections of large-diameter pipelines. In this work, to take into account the effect of hydrostatic pressure on the pipeline wall from oil flowing at different speeds, the solution obtained by M.A. Ilgamov and A.S. Volmyr is used. At the same time, the effect of a stationary fluid flow on the pipeline wall is taken into account in the equation written in forces for the last term of the normal component of inertia forces. The resulting modified equation allows determining the frequency characteristics of the pipeline both according to the rod theory (without taking into account the deformation of the cross section) and according to the theory of shells (taking into account the deformation of the cross section).

Parametric vibrations of the underground oil pipeline

“…With an increase in the internal working pressure, the instability regions for all thinness parameters increase. This is explained by an increase in the natural vibration frequencies, which were studied in [17,18]. 1.…”