Desenvolvimento de metamateriais acústicos com o uso de algoritmo genético e manufatura aditiva

Abstract

Sound absorption materials are used to mitigate noise in various applications, such as corporate environments, automotive and aeronautical industries, factories, among others. Although highly effective at high frequencies, achieving significant sound absorption at medium and low frequencies requires large material thicknesses. This leads to increased mass and device costs. With the advent of additive manufacturing (commonly known as 3D printing) and the continuous development of computing, new ways of designing these materials with more complex structures are being used to overcome these issues. These new structures are known as acoustic metamaterials and possess unusual characteristics not found in nature. In this work, well-established acoustic theories are employed in conjunction with optimization techniques using genetic algorithms. Open-source 3D modeling software is also used to obtain metamaterial geometries with controlled sound absorption properties in the target frequency bands. All of this is integrated using the Python programming language. The designed materials were manufactured using additive manufacturing technology and subsequently experimentally characterized through impedance tube measurements. The experimental results showed good agreement with the developed analytical and numerical models. The percentage error in the resonance frequencies, with respect to the analytical model, was approximately 17% and 6%, respectively, for the numerical and experimental models of the first evaluated geometry, and 6% and 0.7% for the numerical and experimental models of the second geometry. Furthermore, a relationship was established between the device thickness (32 mm) and the wavelengths of both resonance frequencies of the measured sample, approximately 0.058 and 0.084, respectively. The results demonstrate that the proposed model can be confidently used for generating new materials that contribute to the study of acoustic metamaterials.