احمد سلیمانی

In this study, the dynamic behavior and stability of a nanobeam with variable material properties and width under fluid flow are investigated. The width, elasticity modulus and density of the nanobeam vary along its length and are modeled as arbitrary functions of the longitudinal coordinate. The nanobeam is subjected to fluid flow parallel to its length, and the interactions between the fluid and the nanobeam are modeled using a two-way fluid–structure interaction (FSI) approach. To account for size effects in the solid, the non-local couple stress theory is employed, while a corrected velocity model is used for the fluid. The governing equations of the system are derived using Hamilton’s principle, and the FSI problem is solved by applying the Galerkin method. The results show that variations in material properties and cross-sectional dimensions significantly impact the critical velocity and natural frequency of the nanobeam. Additionally, this study highlights the importance of the Knudsen number and slip boundary conditions in accurately predicting the vibrational behavior and stability of the nanobeam at the nanoscale. The findings of this research provide valuable insights for the design and optimization of nanobeams in various engineering applications involving fluid flow.