Optimal design of stochastic aeroviscoelastic systems in subsonic regime using the doublet lattice

Abstract

In a concerted effort to mitigate the global environmental impact, various governments and international organizations have put forth strategies aimed at enhancing the efficiency of products and solutions. The aeronautical and aerospace industries have set forth an ambitious target of eliminating their CO2 emissions by the year 2050. To realize this objective, manufacturers are adopting innovative approaches, including the incorporation of new blade engines, utilization of Sustainable Aviation Fuel (SAF), integration of lighter materials, and the adoption of novel geometric wing shapes designed for enhanced efficiency. However, the implementation of structural and aerodynamic modifications, such as those required for aeroelastic systems, can lead to instability effects, notably the flutter phenomenon. Addressing this challenge, one viable strategy involves the application of vibration control techniques. In this context, the use of passive control with viscoelastic materials emerges as an intriguing option due to its cost-effectiveness and ease of application. Additionally, considering the inherent variabilities in structural and aerodynamic parameters within these systems, there is a need for an efficient stochastic modeling methodology to cater to realistic applications of industrial significance. The present study endeavors to model a stochastic aeroviscoelastic system, specifically focusing on a plate-like wing in a subsonic regime. This is achieved through the integration of stochastic finite element modeling and the Doublet Lattice Method (DLM). The study aims to quantify the impact of increased mass and stiffness, particularly related to the addition of layers and the inclusion of damping from the viscoelastic material. The findings of the research demonstrate a noteworthy 31% increase in flutter speed with a corresponding 38% increase in mass. Although the ratio of speed gain to mass gain is below one in this instance, with a partial treatment approach, it can potentially reach 2. This underscores the advantageous nature of treating aeronautical panels with layers of viscoelastic material. Importantly, the engineer possesses the capability to strategically select deterministic parameters to align with specific objectives between the two defined functions.