Numerical simulation of natural frequencies in the design of micro air vehicle structures

The mechanical resonance of structures is often blamed for their collapse. In the attempt to prevent such usually catastrophic events, the identification of the natural frequencies has usually become a constituent part of the design activity of mechanical structures. Micro Air Vehicles (MAVs) are small size unmanned aircraft. This study aims to give a place to the numerical finite element method (FEM) simulations of the natural frequency during the design stage of the MAVs. In particular, the effect of selected materials and geometrical parameters on the simulated first natural frequency has been analyzed in this study. Carbon fibre reinforced polymer (CFRP) appeared to confer the MAV a significant higher first natural frequency than the aluminum alloy investigated (AA2024). Also, given any of the material investigated (CFRP, aramidic fibre reinforced polymer, AA2024), it was found that MAVs simultaneously having a large radius and thickness of the outer shell and a small height have first natural frequency far larger than in any other geometrical configuration.