Projeto ótimo robusto de sistemas aeroviscoelásticos estocásticos em regime subsônico utilizando Doublet Lattice

Abstract

To reduce the global environmental impact, governments and international organizations have proposed various strategies for more efficient production and solutions. The aeronautical and aerospace industries have committed to zeroing their CO2 emissions by 2050. To achieve this goal, manufacturers are adopting innovative solutions such as more efficient engines, Sustainable Aviation Fuel (SAF), structures with lighter materials, and more efficient aerodynamic geometries. However, to avoid the instability effects resulting from structural and aerodynamic modifications in aeroelastic systems, such as the flutter phenomenon, a viable strategy is the use of vibration control techniques. In this context, passive control using viscoelastic material is an interesting approach due to its low cost and ease of application in structures. Additionally, due to the inherent variabilities of structural and aerodynamic parameters present in these systems, it is necessary to propose an efficient stochastic modeling methodology to deal with more realistic applications. Therefore, this work contributes to the development of a proprietary tool for the robust optimal design of aeroviscoelastic systems in the subsonic regime and increasing structural efficiency through partial treatment using modal strain energy (MSE). As a case study, a Plate Like Wing system in the subsonic regime is used to increase the stability of this structure by combining stochastic finite element modeling, the Doublet Lattice method, and the NSGA II optimizer. The numerical results demonstrate that the conservative effect associated with the damping of the structure is responsible for about 80% of the vibration attenuation, with the thickness of the elastic layers being the most relevant parameter. Additionally, MSE allowed the partially treated system to achieve a structural efficiency 1.8 times greater than the fully treated system. The results in terms of the envelopes of the V-g and V-f diagrams also show that the robust system has a vulnerability 7 times lower than the deterministic system in the flutter speed response, proving the efficiency of the tool developed integrated with the models. With this, it is possible to reduce project safety factors due to uncertainties and achieve advantages such as: increased component lifespan, use of less material in manufacturing, and increased structural efficiency of aircraft.