Three-dimensional free vibration analysis of functionally graded nanocomposite cylindrical panels reinforced by carbon nanotube

► (FG-X) reinforcements can increase the normalized natural frequency. ► The natural frequency decreases with increasing L/R ratio for short cylindrical panels. ► The natural frequency remains unaltered for long cylindrical panels. ► The biggest frequency is happened when CNTs are oriented with Φ=360° and Φ=30°. ► Increasing the CNT volume fraction, increases the frequency of FG-CNTRC panels.