Axial-flow-induced Vibration of a Rod Supported by Two TranslationalSprings

摘要

An axial-flow-induced vibration model was proposed for a rod supported by two translational springs at both ends.For the derivation of the vibration model, the normal mode method was used to solve the random vibration problem of thecylinder subjected to the randomly fluctuating pressure acting on its surface by axial flow. The first natural frequency andmode shape functions for the flow-induced vibration, so-called FIV, model were derived by using Lagrange's method basedon the single mode approximation. The vibration displacement at reactor conditions were calculated by the proposed modelfor the spring-supported rod and by the previous model for the simple-supported(SS) rod. The resulting vibrationdisplacement for the spring-supported rod was larger than that of the SS rod, and the discrepancy between bothdisplacements was much larger at low flow velocity than at high flow velocity. The vibration displacement for the springsupportedrod appeared to decrease with the increase of the spring constant.