Modal Analysis of Composite 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 by consideration of rotary inertia. The free vibration analysis of sandwich panels is studied. Four noded isoparametric shell element is used for FEA. The effects of sandwich design parameters, such as face thickness, core thickness and pitch, on the global bending and vibration responses are determined. 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 and cantilever condition. Free vibration analysis of aluminum honeycomb core sandwich panels using FEA. Sandwich panels have 1.4 times higher fundamental frequency than equivalent face plate. Error between FEA and experimental results is within 5%. Increase in thickness of core increase in natural frequency of the higher mode. Increase in density of the core decreases the natural frequency of the sandwich plate.