Dynamic behavior of nanobeams under axial loads: Integral elasticity modeling and size-dependent eigenfrequencies assessment

TL;DR

This paper investigates the dynamic eigenfrequencies of nanobeams under axial loads using two nonlocal elasticity models, revealing size-dependent effects and the influence of thermoelasticity and initial forces on their behavior.

Contribution

It introduces and compares stress-driven and strain-driven nonlocal elasticity models for nano-beams, providing new insights into size effects and dynamic responses at the nanoscale.

Findings

Eigenfrequencies vary with nonlocal parameters and axial loads.

Stress-driven models show size hardening effects, while strain-driven models show softening.

Thermoelastic effects significantly influence nanobeam dynamics.

Abstract

In this article, eigenfrequencies of nano-beams under axial loads are assessed by making recourse to the well-posed stress-driven nonlocal model (SDM) and strain-driven two-phase local/nonlocal formulation (NstrainG) of elasticity and Bernoulli-Euler kinematics. The developed nonlocal methodology is applicable to a wide variety of nano-engineered materials, such as carbon nanotubes, and modern small-scale beam-like devices of nanotechnological interest. Eigenfrequencies calculated using SDM, are compared with NstrainG and other pertinent results in literature obtained by other nonlocal strategies. Influence of nonlocal thermoelastic effects and initial axial force (tension and compression) on dynamic responses are analyzed and discussed. Model hardening size effects from stress-driven approach is compared to model softening size effects from strain-driven two-phase local/nonlocal approach for increasing nonlocal parameters.