M.R Zamani - Assistant Professor, Mechanical Engineering, Malek Ashtar University of Technology, Tehran, Iran
M Zaretabar - PhD Student, Mechanical Engineering, Malek Ashtar University of Technology, Tehran, Iran
H Mohammadi - Master's degree, Mechanical Engineering, Malek Ashtar University of Technology, Tehran, Iran

In recent years, due to properties such as high specific strength, low weight, and resistance to damagepropagation, sandwich composite panels have been widely used in various industries such as marine, automotive,nuclear, pressure vessels, and aerospace. In this research, three sandwich composite structures with honeycomb,hexagonal and square cores were modeled and analyzed numerically in order to determine the vibrational behavior ofthe structure. In the numerical method, first, the geometric model and the finite element of the desired structure werecreated using Abaqus software, and subsequently, analyses of free vibration behavior, extraction of natural frequenciesand mode shapes were performed. The results of the natural frequency revealed that the structure with the honeycombcore has higher stiffness than that of other structures. The structure with the honeycomb core had ۲.۵% and ۳۱.۲%higher first frequency than those with hexagonal and square core, respectively.

Numerical analysis, Natural frequency behavior, Sandwich structure, Honeycomb core, hexagonal and square core