Study the Strength of Material and Composite Structures of Belly-Landing Mini UAV

Abstract

This paper consists of the design and analysis of the strength of material composite of the fuselage of a Belly-Landing Mini Unmanned Aerial Vehicle (UAV). A belly landing UAV occurs when an UAV lands without its landing gear and uses its underside, or belly, as its primary landing device. Belly landings carry the risk that the UAV may flip over, disintegrate, or catch fire if it lands too fast or too hard [1], so the more important designs parameters for materials used are the specific strength and specific stiffness. Specific strength is defined as the ultimate tensile strength divided by material density, and specific stiffness is defined as Young’s modulus of the material divided by density [Franklin, 2010]. The aim of this Belly Landing Mini UAV is for used in situations where manned flight is considered too risky or difficult and no runway for take-off or landing, such as fire fighting surveillance, while the term 'mini’ means the design of this UAV has a launch mass greater than 100 grams but less than 100 kilograms [2], the objective of this project is the development and design of materials fuselage of a mini UAV with two layer sandwich structures made from composite materials and epoxy resin. For that purposes, 3 variations of the composite materials tensile test specimens have been manufactured in accordance with ASTM D3039 standard and tested its strength. The results showed that the fibre glass and fibre carbon composite with resin epoxy has the maximum tensile strength and Young’s modulus, so that the fabrication and manufacturing of the fuselage component is made by using that material composite. The Von Mises stress is used to predict yielding of materials under any loading condition from results of simple uniaxial tensile tests by using software Autodesk Inventor 2012. The results show that the design is safe caused the strength of material is greater than the maximum value of Von Mises stress induced in the material. The results of flight tests show that this small UAV has successfully manoeuvred to fly, such as take off, some acrobatics when cruising and landing smoothly, which means that the calculation and analysis of structure and material used on the fuselage of the Mini UAV was able to be validated.