Free vibration analysis of sandwich panel

Abstract

Use of Sandwich construction for an aircraft structural component is very common to the present day. One of the primary requirements of aerospace structural materials is that they should have low density, very stiff and strong. Sandwich panels are thin-walled structures fabricated from two flat sheets separated by a low density core. The core investigated here is of aluminium honeycomb structure because of excellent crush strength and fatigue resistance. Sandwich panels have a very high stiffness to weight ratio with respect equivalent solid plate because of low density core. Modeling is developed in FEA (ANSYS) by consideration of rotary inertia. The free vibration analysis of isotropic plate and sandwich panels are studied. The results of FEA (ANSYS) are compared with results of experimental and analytical work. Eight nodded isoparametric shell element is used for FEA (ANSYS). Convergence study is also included for high accuracy of the results. Analytical results are based on classical bending theory. Mode shapes and corresponding natural frequencies are studied for simply supported sandwich panel. Parameter studies of isotropic plate and sandwich panel are also covered in this analysis. A detailed parameter study has been carried out of a simply supported sandwich panel by increasing the core depth as a percentage of its total thickness, while maintaining a constant mass.