Stability and nonlinear vibration analysis of fluid-conveying composite pipes with elastic boundary conditions

• Published in: Thin-walled structures Vol. 179; p. 109597
• Main Authors: Zhou, Jie, Chang, Xueping, Xiong, Zijie, Li, Yinghui
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2022
• Subjects: Composite pipe; Elastic boundary conditions; Fluid-conveying pipe; Homotopy analysis method; Nonlinear vibration; Stability analysis; Elastic boundary conditions; Stability analysis; Composite pipe; Nonlinear vibration; Fluid-conveying pipe; Homotopy analysis method
• ISSN: 0263-8231; 1879-3223
• DOI: 10.1016/j.tws.2022.109597

Considering geometric nonlinear deformation and elastic boundary conditions, this paper mainly investigates the stability and nonlinear vibration characteristics of fluid-conveying composite pipes. Based on Euler–Bernoulli Beam Theory and the effects of von Karman nonlinearity, using Kelvin–Voigt model and Hamilton variational principle, the dynamic governing equations and elastic boundary conditions of composite pipe are established. Firstly, the modal function suitable for elastic elastic boundary conditions is derived by Galerkin method, and the stability of fluid-conveying composite pipe system and the influence of elastic boundary conditions on the unstable critical velocity are analyzed. Then the Homotopy analysis method is used to solve the nonlinear vibration characteristics of the composite pipe system. The effects of viscoelastic coefficient, initial amplitude and fiber orientation on the nonlinear natural frequencies are given. The results show that the translation spring has little effect on the instability critical velocity, while the rotation spring will increase the instability critical velocity and make the system more stable. The increase of viscoelastic coefficient and fiber orientation will lead to the decrease of nonlinear frequency, the larger the initial amplitude, the larger the nonlinear frequency. •The novelty of this paper is concerned with the combined effects of the viscoelastic coefficient, initial amplitude, fiber orientation angle, the axial force, geometric large deformation, the stiffness coefficients of the translation spring and the rotation spring on stability and nonlinear vibration characteristics of fluid-conveying composite pipes.•At present, there is little research on the nonlinearity of the flow pipe of fiber composite materials, so it needs to be discussed in depth.•Secondly, another novel point is to study the influence of generalized boundary conditions on the vibration of flow pipelines, and introduce homotopy analysis method to solve the nonlinear vibration equation to obtain its numerical solution.