Free Vibration Analysis of Shear Deformable Small-Scale Tubes

This study presents an approach for investigating free vibration problem of small-scale tubes based on modified couple stress theory in conjunction with higher order shear deformation tube model. The size effect is captured through utilization of a length scale parameter involved in modified couple stress theory. A newly developed refined tube model is employed to satisfy friction-free conditions on inner and outer surfaces of micro-tubes. Hamilton’s principle is used as a variational technique for derivation of governing system of equations. For axial vibrations, an analytical procedure is conducted, while for transverse vibrations differential quadrature method is used as a numerical technique. The correctness of numerical results are verified through comparisons made with results which are available in the literature for limiting cases. The analyses reveal the effects of size and transverse shear deformation on the natural frequencies of micro-tubes.