Stability analysis of viscoelastic curved pipes conveying fluid

Abstract

Based on the Hamilton' s principle for elastic systems of changing mass, a differential equation of motion for viscoelastic curved pipes conveying fluid was derived using variational method, and the complex characteristic equation for the viscoelastic circular pipe conveying fluid was obtained by normalized power series method. The effects of dimensionless delay time on the variation relationship between dimensionless complex frequency of the clamped-clamped viscoelastic circular pipe conveying fluid with the Kelvin-Voigt model and dimensionless flow velocity were analyzed. For greater dimensionless delay time, the behavior of the viscoelastic pipe is that the first, second and third mode does not couple, while the pipe behaves divergent instability in the first and second order mode, then single-mode flutter takes place in the first order mode.

Dynamic analysis for axially moving viscoelastic panels

“…In the eigenvalue spectra of moving viscoelastic beams or plates, the effect that the system does not experience couple-mode flutter typical of elastic materials, is well-known, and has been reported, e.g., by Lee and Oh (2005) and Zhou and Wang (2007). Similar behaviour has been found in the studies on stability of viscoelastic pipes conveying fluid (Wang et al, 2005b). Our results coincide with the previously reported findings.…”

“…4 show that the third mode becomes stable, and with further increase of the creep time constant, the second mode becomes stable, and finally also the first mode becomes stable for all values of velocities. The phenomenon that the higher modes become stable when the viscosity is increased can be seen also in the results by Lee and Oh (2005), Wang (2007, 2008), and Wang et al (2005b).…”

An application of data-driven modeling for hydroelasticity of an elastically supported semi-circular pipe conveying fluid

“…In recent years, the dynamics of more realistic pipe-fluid systems are becoming increasingly concerned. For instance, the instability of a viscoelastic (Wang et al ., 2005; Yang et al ., 2007) or functionally graded pipe (Deng et al ., 2017) conveying pulsative (Ni et al ., 2014; Luo et al ., 2016) or viscous (Guo et al ., 2010; Hellum et al ., 2010) fluid immersed in thermal environment (Reza and Reza, 2018). As more and more mechanical factors were considered, the theoretical modeling and hydroelastic analysis of pipe-fluid system was also becoming increasingly difficult.…”

On Travelling Web Stability Including Material Viscoelasticity and Surrounding Air

“…Previous studies on moving viscoelastic materials interacting with surrounding uid seem to be rather limited to the cases of beams having a circular crosssection [24,25,26] and to viscoelastic pipes conveying uid [27,28]. Recently, Saksa et al [29] presented a model for axially moving thin webs, in which the material viscoelasticity was taken into account by the Kelvin-Voigt model and the effects of the surrounding air were approximated using an added mass approach.…”