STABILITY BOUNDARIES FOR FLUID-CONVEYING PIPES WITH FLEXIBLE SUPPORT UNDER AXIAL LOAD

The interaction of fluid velocity and axial load on the instability of a pipe is investigated. The downstream end of the pipe is free and th e upstream end is pinned with a rotational spring. For an infinite spr ing stiffness, the system reduces to a cantilevered pipe. Flutter or d ivergence instability may occur, depending on the combination of veloc ity and load. Results are obtained by direct numerical solution of the governing equations. An approximate procedure based on a variational principle is also presented. The effects of the axial load, spring sti ffness, and mass parameter are studied, and the results are compared t o the standard case of a cantilevered pipe without axial load.