PSI - Issue 71

Prathamesh Patil et al. / Procedia Structural Integrity 71 (2025) 388–394

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disasters. Structural analysis was performed so that the drone could withstand any type of mechanical stresses encountered during operation. As it was expected for the drone to carry supplies over a large distance, it is necessary that the design must be light weight as well as robust. Modal and harmonic analysis was also performed in order to support the design. This was performed to study the natural frequencies and their corresponding deformations. Harmonic analysis was performed to protect the electronic components from damaging, as the structural vibrations get transferred to them during the flight. Computational Fluid Dynamics (CFD) helps to study the airflow around the drone during the flight, eventually helping in the design. It helped in designing a drone which can withstand various conditions and minimizing the time required for testing and making it cost-effective. The drone is equipped with a payload box which is engineered in a way such that it ensures the safe and efficient delivery of supplies. This mechanism is made up of light weight material which does not affect the dynamics of the drone’s flight. The box keeps the item safe and secure. Development of such drones represent the advancement in UAV technology.

2. Airframe and Material Selection

The UAV was designed with constraints. The individual length, width and height of the frame does not exceed 1.2 m. Also, the total weight under which the UAV was designed was 2 kg. Despite various configurations available, the team decided to go for X-Configuration drone due to more stability, centralized centre of gravity, improved efficiency, and enhanced safety. This configuration ensures the mounting of critical components in the frame making it easy. Also, it contributes in achieving a consistent thrust to weight ratio. While designing and fabricating a multicopter frame, material selection plays a crucial role, which ensures the high strength, lightweight, durability, overall performance, and a highly efficient frame. In order to maintain the strength, accessibility of parts and cost effectiveness of the frame, materials mentioned below were selected. Material selection was executed by comparing their mechanical properties such as density, strength, and modulus of elasticity.

Table 1. Material selection

Material

Tensile Strength

Density

Ease of Manufacturing

Salient Features

PLA 60-70 MPa

1240 kg / m 3

Easy (3D printing)

Biodegradable, easy to print, lower impact resistance compared to ABS, Good vibration absorption quality Extremely lightweight, high strength to weight ratio, high stiffness, low thermal expansion

Carbon Fiber

500-600 MPa 1600 kg / m 3

Moderate (Molding)

Aero ply 30-50 MPa Lightweight polywood, good strength to weight ratio. Table 1 shows different materials available for fabrication of the drone. Suitable material was selected for the fabrication. Material such as PLA was useful for the parts that could be made by additive manufacturing, using FDM 3D printing technology. Similarly, carbon fibre and aeroply material were used for their high strength and lightweight features. Some additional parts were used such as Velcro straps and landing leg grips for better ground friction. 2.1 Additive Manufacturing Process 600 kg / m 3 Moderate (Cutting, Laser cutting)