Three-dimensional vibration analysis of curved pipes conveying fluid by straight pipe-curve fluid element

• Published in: Applied mathematical modelling Vol. 121; pp. 270 - 303
• Main Authors: Wen, Huabin, Yang, Yiren, Li, Yundong, Tao, Jing
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.09.2023
• Subjects: Curved pipe conveying fluid; Finite element method; Fluid-structure interaction; Straight pipe-curve fluid element; Three-dimensional vibration; Finite element method; Straight pipe-curve fluid element; Curved pipe conveying fluid; Fluid-structure interaction; Three-dimensional vibration
• ISSN: 0307-904X
• DOI: 10.1016/j.apm.2023.05.002

•The straight pipe-curve fluid theory is proposed to analyze the three-dimensional vibration of curved pipes conveying fluid.•The straight pipe-curve fluid element is established based on straight pipe-curve fluid theory.•The coupling vibration mechanism between in-plane and out-of-plane motion of the curved pipe conveying fluid is revealed. A three-dimensional straight pipe-curve fluid theory is developed for the modeling of pipes conveying fluids with arbitrary configurations, and the corresponding finite-elements-based numerical approach to the nonlinear dynamics of curved pipes is proposed. Initially, the theoretical model of a straight pipe-curve fluid system is built along with its corresponding finite element. Subsequently, this proposed methodology is tested by conveying fluids through semicircular curved pipes. Coupling vibration mechanisms between in-plane and out-of-plane systems are explored. Finally, the influence of non-linear terms related to internal forces on the vibrations of curved pipes conveying fluid is discussed to simplify the theoretical model. The results provide useful insights into the subject matter: (i) The three-dimensional straight pipe-curve fluid element proposed is effective in analyzing the vibration behavior of curved pipe conveying fluid; (ii) When the parameter vibration of the out-plane frequency occurs and the pulsation frequency is about two-thirds of the out-plane second natural frequency, the in-plane and out-of-plane vibrations couple with the beat frequency; (iii) When combined vibration of out-plane first and second natural frequencies occur, in-plane and out-of-plane vibrations coupled with the out-plane first natural frequency; (iv) The main factors causing out-of-plane and coupling vibration of in-plane and out-of-plane systems are nonlinear terms related to axial force and in-plane transverse force.