| Título: | Numerical and experimental investigation of composite material swept wings |
| Autor: | Hermann Luís Lebkuchen |
| Programa: | Engenharia Aeronáutica e Mecânica |
| Área de Concentração: | Projeto Aeronáutico, Estruturas e Sistemas Aeroespaciais |
| Orientador : | Roberto Gil Annes da Silva |
| Coorientador : | Carlos Eduardo de Souza |
| Ano de Publicação : | 2018 |
| Curso : | Mestrado Acadêmico |
| Assuntos : | Materiais compósitos |
| t | Aeroelasticidade |
| t | Otimização |
| t | Laminados |
| t | Engenharia de materiais |
| Resumo : | This dissertation presents an aeroelastic tailoring investigation of sweep angle effects on aeroelastic response of simplified flexible flat-plate wing like models made of isotropic and fiber reinforced composite material with constant and variable stiffness. A numerical framework is implemented in Matlab® to manage and automate aeroelastic stability analysis with finite element method using DS Abaqus® and panel method Zona6 using Zaero®, for structure and aerodynamic models, respectively. The flutter onset equation is solved with the g-method through Zaero®. An optimizer is coupled to the numerical framework using the Matlab® genetic algorithm toolbox. Numerical results are compared with experimental and operational modal analysis and aeroelastic stability wind tunnel tests for isotropic structure. The wash-in and wash-out effects are investigated in wind tunnel tests through strain measurement under aerodynamic loading. The aeroelastic system continuity is explored through mapping procedure for laminates with one and two variables. Symmetric and non symmetric laminates with one up to six optimization variables are investigated. The structure continuity of variable fiber disposal and the minimization of optimization problem variables is performed with curvilinear parametrization relating wing root and tip angles. The potential of optimized tailored unidirectional as well as tow-steered laminates to enhance flutter speed is presented and compared with isotropic wings made of aluminum. A methodology based on trigonometric approximations is employed for variable stiffness composites to specify continuous fiber paths from discrete angles at each finite element. Both constant and variable stiffness are manufactured using a fiber placement machine for lamination and cured in auto-clave. The improvement of composite structures in divergence and flutter speeds for forward as well as backward and unswept models is presented. |
| Data de Defesa : | 13/07/2018 |
| Texto na íntegra : | [Visualizar] |