Deflection, buckling and vibration analyses for a sandwich nanocomposite structure with foam core reinforced with GPLs and SMAs based on TSDBT

The purpose of this research is to investigate deflection, buckling and vibration for a five-layer sandwich nanocomposite beam, with reinforcements of graphene platelets (GPLs) and shape memory alloys (SMAs), and a foam core. To predict the behavior of the beam, theoretical formulations are derived based on the third order shear deformation beam theory (TSDBT). In order to check the validity and accuracy of the present work, the obtained results are compared with the results of other works and there is a good compatibility between them. It is concluded from this research that by using foam as the core, the weight of the structure is reduced, and also, the use of GPLs and SMAs as a reinforcement in the beam structure increases the stiffness and the equivalent elasticity modulus, so the ratio of strength to the weight of the structure increases. As a result of which the deflection decreases, the critical buckling load and the natural vibration frequencies of the beam increase. For example, it can be seen in the results that by increasing the volume fraction of GPL from 0 to 0.03, the deflection of the beam decreases by 44% and the first natural frequency of vibration and the critical buckling load increase by 31% and 79%, respectively.