Damping and instability characteristics of uniform and non-uniform composite multifunctional semi-active sandwich structures under rotating environment

In the present study, vibration and instability characteristics of the rotating carbon nanotubes (CNT) reinforced magnetorheological (MR) elastomer embedded sandwich composite plate with uniform and non-uniform composite face sheets under in-plane loading have been investigated numerically using finite element (FE) method. The efficacy of the FE method by deriving the governing equations using higher order theory is verified by comparing the natural frequencies assessed using experimental studies on the MR elastomer and CNT reinforced MR elastomer sandwich composite structures under different rotational speeds. This research also predicts the effects of CNT and magnetic fields on material damping, as well as rotating effects on structural damping due to geometrical non-linearity, in terms of natural frequencies and their corresponding modal loss factors of uniform and non-uniform multifunctional smart sandwich composite plates. Further, the instability regions of the uniform and non-uniform multifunctional smart sandwich plates under in-plane periodic load are analysed with the influence of various rotating speeds and magnetic field intensities. Therefore, it could be concluded that the CNT reinforcement on the MR elastomer layer significantly improves the stiffness, damping and reduces the instability regions of spectra of the rotating uniform and non-uniform multifunctional smart sandwich composite plates.