Dynamic response of embedded Timoshenko CNTs exposed to magnetic and thermal fields subjected to moving load based on doublet mechanics

This paper uses the nanomechanical theory to examine the dynamic behaviour and response of embedded zigzag and armchair carbon nanotubes (CNTs) under moving load in thermal and magnetic fields. The nanoscale size effect of CNTs is imposed using the doublet mechanics theory. The CNTs modelled as a Timoshenko beam structure with shear stress effects. The modified motion and non-classical boundary condition equations of embedded CNTs under moving load and subjected to thermal and magnetic loads are obtained using Hamilton's principle. Navier's analytical solution and Newmark's time integration methods are imposed to obtain the time domain responses of simply supported CNTs. The computational accuracy of the proposed model has been validated and proven by previously published studies for free and forced responses. In the parametric analyses, the influence of the doublet length scale parameter (DMP), armchair and zigzag structures of CNTs, moving load's velocity, magnetic field’s intensity, temperature rise, and the stiffnesses of two-parameter Pasternak foundation on dynamic responses of CNTs are considered. It is obtained that the DMP significantly affects CNTs' free and forced vibration under a moving load. The DMP increase reduces system stiffness, lowering the dimensionless frequency and increasing the dynamic amplification factor. Also, the DMP has a greater influence at higher vibration modes and beam aspect ratios. The proposed modelling is helpful for the analysis, design, and remote control of MEMS/NEMS as nano-transport systems, nanosensors, and nano-actuators manufactured from CNTs.