Size-dependent coupled bending-torsional vibration of functionally graded carbon nanotube reinforced composite Timoshenko microbeams

This paper investigates the free vibration of a carbon nanotube-reinforced composite Timoshenko microbeam considering the effect of axial load and bending-torsion coupling. The microbeam properties are developed based on the micromechanical model concerning the extended rule of mixtures. The governing equations of motion are derived using the modified couple stress theory and Hamilton’s principle. The uniform nanotube distribution and three functionally graded distributions are considered for the carbon nanotube-reinforced composite microbeam. The generalized differential quadrature method is applied to the governing equations for deriving the natural frequency under different boundary conditions. Next, the effects of different parameters, including nanotube distribution, geometric characteristics of microbeam, material length scale, and nanotube volume fraction, on the natural frequency are demonstrated through different tables and diagrams. Among obtained results is the significant effect of the carbon nanotube volume fraction on the natural frequency of the microbeam. Also, the nonconformity between the mass and elastic axes leads to the natural frequency reduction. The comparison between obtained results and results of other credible papers confirms the validity of obtained results.

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Opracowanie rekordu ze środków MNiSW, umowa nr SONP/SP/546092/2022 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2024)