Research on impact vibration response of hinged fluid-conveying pipe with bilateral gap constraints

Abstract

Factors such as loose supports or barriers over the fluid-conveying pipe may cause bilateral gap constraints. Flow-induced vibration will occur during pumping, which leads to collision between the pipe and the constraints. A piecewise linear spring model with large stiffness is employed to simulate the collision process between the pipe and the constraints, and numerical simulation is carried out for the collision of hinged fluid-conveying pipe with the bilateral gap constraints. The dynamic characteristics of hinged fluid-conveying pipe with pulsating internal flow excitation and bilateral gap constraints during impact vibration are studied. Influences of various parameters including frequency, average flow rate of the pulsed internal flow excitation, position of the bilateral constraints, and gap dimensions on the system are investigated. Three paths are found for the pipe system entering chaotic window from stable periodic motion: entering chaotic window after the occurrence of period-double bifurcation, transitioning into chaotic window after developing almost periodic motion, and jumping into chaotic window directly. If the distance between two constraints is closer, the pipe between the constraints will be subject to stronger constraints during the collision process, which can cause the system to enter chaos easily. Many dynamic phenomena have been observed, such as a sliding bifurcation when periodic incomplete chattering-impact developing periodic complete chattering-impact, strong centrosymmetric properties in the bifurcation diagram and the Poincaré map at the mid-point of the pipe, jumping between stable periods, period-double vibration response, inverse period-double vibration response, grazing motion, and viscous motion.