Vibration analysis of the multi-walled carbon nanotube reinforced doubly curved laminated composite shallow shell panels: An experimental and numerical study

Abstract

In this study, free and forced vibration analysis of the multi-walled carbon nanotube reinforced doubly curved laminated composite shallow shell panels has been performed. The governing differential equation of motion of the doubly curved laminated composite shallow shell panel is formulated using higher order shear deformation theory with the Lagrangian approach. In a finite element formulation , the mathematical model is derived with a nine-node quadrilateral element considering seven degrees of freedom at each node. The efficiency of the present finite element model (FEM) is demonstrated and compared by validating the results with the available literature, and it is also compared with the experimental measurements of the cylindrical laminated composite shell panel with and without multi-walled carbon nanotube reinforcement. Material properties of the laminated composite structure with and without multi-walled carbon nanotube reinforcements are evaluated through the impulse excitation vibration test in accordance with the ASTM E1876-15. The influence of multi-walled carbon nanotube on the stiffness and structural integrity of the curved laminated composite shallow shell panels is also studied in terms of natural frequencies. Parametric analysis for the multi-walled carbon nanotube reinforced doubly curved laminated composite shallow panel is performed to study the influence of radius of curvature, shell geometry, thickness ratio, aspect ratio, stacking sequence, and the boundary conditions on structural performance. The forced vibration behavior of the curved composite shallow shell panel is studied with the different geometry configuration, and the influence of multi-walled carbon nanotube in the transverse vibration response is also studied. It has been concluded that the rigidity and structural performance of the doubly curved laminated composite shell panels are enhanced with the reinforcement of multi-walled carbon nanotube.