Author(s): Silva, João
Date: 2017
Persistent ID: http://hdl.handle.net/10400.26/23156
Origin: Academia da Força Aérea
Subject(s): Air power; FAP; UAS class I; Wing structural design; Structural optimization; Composites; Poder aéreo; FAP; UAS class I; Design estrutural de asa; Otimização estrutural; Compósitos; Domínio/Área Científica::Engenharia e Tecnologia::Engenharia dos Materiais
Alferes Aluno ENGAER 137735-D. Estabelecimentos de ensino superior: AFA/IST
In the context of air power in a Global scale, unmanned aerial systems (UAS) are a present and future necessity, reason why, they are part of the Portuguese Air Force (FAP) strategic vision and part of the Portuguese National Strategy for the Sea 2013-2020. Since 2008 the FAP has been developing UAS ever more capable and, nowadays, some of its experimental platforms are already being used operationally, both nationally and internationally. In order to expand their use, in a safe and responsible manner, for search and surveillance missions over the vast area under Portugal’s jurisdiction, there is the necessity to manufacture new platforms capable of fulfilling all the operational and airworthiness requirements and to establish procedures for their eventual mass production. In light of these necessities, the present master’s thesis consists of the design and optimization of the structure of the wing of a new operational platform with a maximum take-off weight of 145 kg (UAS class I). Parallelly to the operational use, this platform will also play the fundamental role of being the test model – at a reduced scale – for a large UAS (class II), currently in development by a consortium between the FAP, national companies and the Portuguese National Ministry of Defense (MDN). The wing design and optimization process, involved determining the loads acting on the structure (definition of the aircraft’s flight envelope and identification of the wing’s critical loading condition), planning the general shape and components layout, choosing materials (composites – manufacturing of specimens and experimental testing to obtain their properties), and then, shaping, sizing and optimizing its many components to give every part just enough strength without excess weight and also to reduce costs. All design decision were fundamented based on regulations (e.g. the NATO STANAG AEP-83), structural design manuals, books and scientific articles, in order to guarantee the certification of the structure in terms of airworthiness. The optimization process used / created – “chain top-down approach” – proved to be simple and effective and consisted in an individual but interconnected optimization, of each component, following a hierarchical sequence, in accordance with the structural importance of each one. All the geometric models produced (3D) and all the structural analysis performed (numerical analysis resorting to the discretization of the structure using finite elements – FEA), were achieved by using the software SolidWorks 2016 x64 Edition. The final wing model obtained, fulfilled every structural requisite (capable of enduring between - 1.5 and 4 G’s with a wing tip displacement < 5% of half-wing span), perational requisite (capable of carrying up to 10 kg of suspended payload from each half-wing), and weight requisite (mass < 26.2 kg), with a manufacturing cost, in terms of materials, close to 3000 €.
