Thermal free vibration examination of sandwich piezoelectric agglomerated randomly oriented CNTRC Timoshenko beams regarding pyroelectricity

Abstract

For the first time, thermal free vibration examination of sandwich piezoelectric agglomerated Timoshenko beams strengthened by carbon nanotubes is addressed here considering the pyroelectric effect. The top, and the bottom layers are piezoelectric layers serve as a sensor. The host lamina is a polymer matrix strengthened by means of randomly oriented carbon nanotubes. Mori-Tanaka's approach is used to define the thermal and mechanical attributes of the carbon nanotube reinforced nanocomposite. The effect of carbon nanotube agglomeration is incorporated to the constitutive relations. The behavior of the materials is considered to be linearly elastic. The Chebyshev-Ritz method is used to derive the correlated natural frequencies. The influences of the pyroelectricity and the carbon nanotube agglomeration on the first natural frequency are investigated for three different boundary conditions. The results show that the first natural frequency decreases by neglecting the effect of the pyroelectricity. In addition, the agglomeration eliminates the possibility of static instability predicted for the nanocomposite beam exposed to a thermal ambient.