Analysis Of Linear And Nonlinear Dynamics Of Pipes Conveying Fluid

Pipes conveying fluid are widely used in shipping industry, aircraft industry, nuclear industry and so on. The vibration of pipes conveying fluid enjoy high popularity due to fluid structure interaction(FSI) in recent years. In this paper, the receptance method is used to solve the linear dynamics of the pipes conveying fluid while the incremental harmonic balance method is used to solve the nonlinear dynamics. In general, the work on the linear dynamics is to deal with the elastic support with damping and the complex geometry pipelines, and the work on nonlinear dynamics is to investigate the mechanism of the vibration of pipes conveying fluid. The specific content is as follows:Firstly due to Hamilton principal, the linear and nonlinear motions of equations are formulated respectively. Then the receptance method and the incremental harmonic balance method are introduced in detail and the concrete solving steps are figured out.Secondly the linear dymanics of pipes conveying fluid including the straight pipes, semi-circular pipes and complex piping system are investigated using the receptace method in this paper. The straight pipes conveying fluid with rigid support are computed, the results are compared with the experiment, then the elastic support with damping is introduced, the multi-span straight pipes conveying fluid is simulated. For the semi-circular pipes conveying fluid both the clamp-clamp boundary and the clamp-elastic boundary is simulated, the influent on the elastic support is discussed in the paper. At last, the model of a complex piping system is introduced and the linear dynamics are discussed. It is shown that the receptance method is convienient with the complex piping system with the elastic damping support.At last, the nonlinear dynamics of the pipes conveying fluid are discussed using the incremental harmonic balance methd(IHB) on both the pin-pin straight pipe and the cantilevered straight pipe. The effect of the internal fluid velocity, mass ratio, the stiffness of the nonlinear constraint, the tip lumped masses on the amplitude-frequency characteristics of the pipes conveying fluid are investigated and the regular conclusions are got through the comparison. The work on nonlinear dynamics of pipes conveying fluid using the IHB method can provide detailed guidance on the mechanism of the vibration of pipes conveying fluid...