STRUCTURAL EVALUATION OF BIODEGRADABLE POLYMER AIRFOILS FOR UNMANNED AERIAL VEHICLES

Abstract

This study investigates the feasibility of using a biodegradable polymer of renewable origin in the manufacture of airfoils for small unmanned aerial vehicles. The research problem centers on the need to identify structural alternatives that combine low weight, adequate mechanical strength, and ease of fabrication, considering the limitations of balsa wood and aluminum in terms of cost, availability, environmental impact, and production processes. The research adopted an experimental and comparative approach. Initially, ten airfoils were produced by additive manufacturing, varying infill configurations and wall thickness. Primary data included mass, density, structural behavior observed in qualitative tests, and results generated by finite element simulations. Secondary data were used for the physico-mechanical characterization of the materials analyzed and to support the choice of printing parameters, polymer properties, and the structural behavior of lightweight airfoils. The analyses involved direct measurements, digital modeling, density calculation, and comparative mechanical assessment against equivalent models in balsa wood and 6061-T6 aluminum, using von Mises stresses and displacements as performance metrics. The results showed that external wall configurations of 0.8 mm offer the best balance between stiffness and mass, whereas 0.4 mm walls exhibited structural failures and 1.2 mm walls led to a weight penalty. The simulations indicated that the biodegradable polymer has higher strength than balsa wood but remains inferior to aluminum in absolute stiffness, although it offers advantages in sustainability and manufacturing flexibility. It is concluded that the material analyzed is technically feasible for airfoils of small unmanned aerial vehicles when optimized printing configurations are adopted, especially a wall thickness of 0.8 mm and layer orientation aligned with stress trajectories. Based on the results, its use is recommended in lightweight structures that prioritize strength-to-weight ratio, material sustainability, and manufacturing economy, while maintaining attention to thermal limitations and the need for structural adjustments according to mission requirements.