Study the Effects of Free Vibration and Effective Elastic Properties with Variation of Layer Orientation of Symmetric Laminate Plates

K. Pradeep Chand, K. Chaitanya

Abstract: Composite materials are play a key role in a aerospace structures. For those structures, it is required a high natural frequency, low weight and high strength etc. Composite materials are full filling these properties. The layer orientation, aspect ratio, laminate thickness, boundary conditions and type of material are key parameters to determine the natural frequency. A rectangular composite (graphite/epoxy) symmetric laminate plate having 4-layers with simply supported boundary conditions are assumed. With the help of MATLAB programming hundred laminates (samples) of 10 units varying layup configuration are developed. For each sample, the natural frequency and Effective elastic properties are calculated by using Classical Laminate Plate Theory (CLPT) and Navier solution in MATLAB. Analytical results of each sample, the natural frequency and Effective elastic properties are compared to the AUTODESK Simulation composite design software. Investigate, for which layup configuration shows the highest and lowest natural frequency. And how the Effective elastic properties are varies with layer orientation.

Keywords: Symmetric laminate, free vibration, CLPT, Effective elastic properties, MATLAB