Analysis of the effect of nonlocal factors on the vibration of nanobeams

Abstract

Abstract Currently, the Eluer-Bernoulli beam nonlocal theory does not fully consider the effects of foundation deformation and axial force on the beams, and cannot accurately reflect the real mechanical properties of nanobeams. The primary objective of this study is to introduce a novel computational method designed for an enhanced characterization of the vibrational behavior of nano beams. Initially, this method incorporates the influence of foundation deformation on beam bending, accounts for the effects of axial forces, integrates Eringen's nonlocal theory, and establishes a modified Euler-Bernoulli beam theory model for the first time, accompanied by a degradation validation of the model. Subsequently, the Laplace transform and Hasselman's complex mode synthesis method are utilized to solve the model, providing the first derivation of the state-space transfer function for the nano beam vibration model based on the modified Euler-Bernoulli beam theory that includes axial force effects. Lastly, the study elucidates the impact of nonlocal factors and various parameters on the vibration characteristics of nanobeams. The results show that the order n increases, and the peak frequency value moves in the direction where the nonlocal factor tends to zero. When the order n is less than 6, the frequency peak is mainly concentrated in the interval where the nonlocal factor is greater than 0 and less than 0.1. At the same order, the beam length increases, and the peak frequency moves in the direction of increasing non-local factor. The modified geometric parameters and the foundation beam stiffness parameters have a greater effect on the peak of the beam's vibration mode in the higher order case and a lesser effect in the lower order case. The larger the nonlocal factor, the larger the peak of the vibration mode. The foundation beam stiffness parameter also has an effect on the direction of the peak vibration mode at the 1st and 2nd orders. The research results will help to predict the vibration behavior of nano beams under different conditions more accurately and provide an important reference for related applications.