Development of a novel Galerkin transformed differential quadrature method and its application to size dependent nonlinear vibration analysis of fluid conveying carbon nanotubes

Date

2023-9-04

Author

Kılıçarslan, Doğuhan Nuri

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

225
views

354
downloads

Cite This

In this thesis, nonlinear vibration characteristics of fluid conveying carbon nanotubes (CNT) are examined using nonlocal strain gradient theory (NSGT) to capture the small-scale effects. CNT is modeled with Euler-Bernoulli beam assumptions with large deflection nonlinearity using von-Karman assumptions and the effect of the nonlinearity on the instabilities caused by the fluid flow is considered. Spatial discretization is performed with the novel approach of Galerkin transformed differential quadrature method (GtDQM) which can apply different higher-order boundary conditions and obtain symmetric system matrices. The spatially discretized nonlinear equation of motion is then converted to nonlinear algebraic equations using the harmonic balance method (HBM) to be solved by Newton's method with pseudo-arc-length continuation. Critical flow velocities that cause instabilities are found and limit cycle oscillation (LCO) characteristics due to nonlinearity are obtained in the frequency domain instead of using time domain simulations. Finally, the effects of changing nonlocal and length-scale parameters on the LCO characteristics for different vibration amplitudes are examined.

Subject Keywords

Nonlinear vibrations, Carbon nanotubes, Differential quadrature method, Fluid-structure interaction, Harmonic balance method

URI

https://hdl.handle.net/11511/105409

Collections

Graduate School of Natural and Applied Sciences, Thesis