Vibration Analysis of Stiffened Composite Plates Reinforced by Nano materials: Analytical and Experimental Investigations.

In this work, rectangular plate samples are designed and fabricated using four arrangements: pure epoxy with a stiffener, pure epoxy plate without a stiffener, homogeneous composite plate with 0.5% Vf and a stiffener, and homogeneous composite plate with a FGM stiffener. The mathematical model is formulated based on the first-order shear deformation theory (FSDT). The free vibration test is conducted, and the signal is analyzed to obtain the free vibration characteristics. The results show that the homogeneous composite plate with 2% Vf and FGM stiffener exhibited a significant improvement in the natural frequency. However, using a Functionally Graded Material (FGM) stiffener and increasing the nano-volume fraction increases the natural frequency. Also, the plate without any filler (pure epoxy) and without a stiffener has the lowest frequencies among the composite plates employed. The discrepancy between the analytical and experimental techniques was no more than 10%.