Numerical Investigation on the Low-Frequency Vibroacoustic Response of an Aluminium Extrusion Compounded with Acoustic Metamaterials

This paper focuses on the low-frequency vibroacoustic characteristics of aluminium extrusion compounded with acoustic metamaterials. According to the actual geometry of floor aluminium extrusion of a high-speed train, a 1 m × 1 m and a 3 m × 3 m vibroacoustic models of the aluminium extrusion were established, respectively, based on the finite element method. Then a reasonable aluminium extrusion modelling and simulation size was discussed. Taking the first-order bending modal frequencies of different size aluminium extrusions and low weight as the objective functions, different beam-like resonators were optimised based on the multi-island genetic algorithm. Finally, the vibration control effect of the acoustic metamaterials on aluminium extrusions of different sizes, and the effects of different measures on vibroacoustic reduction of the aluminium extrusion were analysed. The results show that the acoustic metamaterials are more effective than the traditional measures on the controlling of single resonances.