Stability And Numerical Simulation Of Pipes Conveying Fluid On Two-parameter Foundation With Distributed Follower Force

In recent years, with the pipes conveying fluid is widely used among thepeople’s production and living, coupled with the pipeline explosion happenedrecently, to people’s lives and property has brought great loss, which are illustrated inthe study of pipes conveying fluid stability is of great practical significance.The thesis mainly studied the nature frequency and stability of pipes conveyingfluid with distributed follower force on two-parameter foundation, and simulated bythe finite software ADINA. Based on the existing foundation of Pasternak, theimpact of two kinds of foundation stiffness on the stability of pipeline is studied,considering the effect of the distributed follower force.1. The vibration differential equation of pipes conveying fluid with distributedfollower force on two-parameter foundation is derived on the basis of existingresearch, the dimensionless equations of motion is obtained.2. The system modal functions are obtained by using the complex mode methodto solve the dimensionless equations of motion, Analyzes the combination of fourdifferent foundation stiffness and four different qualities than the first and secondorder natural frequency along with the change of flow velocity, With increasingfoundation stiffness and mass ratio, the nature frequency of the system increases,which impact more on the first than the other. The foundation rigidity provides somerestraint to vibration performance of the pipe.3. By solving eigenvalue problem of frequency equation for system thedimensionless critical flow velocity along with the change of dimensionlessdistributed follower force curve, and the combination of system frequency alongwith the change of flow velocity, distributed follower force under the four differentfoundation stiffness and analysis of the system instability under different conditions.4. The bottom node of the pipes displacement curves with time under differentparameter combination was obtained by using the finite software ADINA to simulate. Analyzed the methods of pipes instability and foundation stiffness on the systemstability, and theoretical studies were compared with the previous sections, theresults agree well.Through theoretical analysis and simulation research, it can be seen that twokinds of foundation stiffness parameters have certain influence on the stability ofsystem, the influence of shear foundation stiffness are greater than the foundation oflinear stiffness.