Optimization piezoelectric metamaterials by genetic algorithm for optimal vibration suppression

Broadband vibration suppression is a major challenge in engineering applications. In this paper, two Bragg bandgaps of a piezoelectric metamaterial beam with a shunted circuit are bridged to form an ultrawide bandgap by using the genetic algorithm. Piezoelectric patches are periodically attached to the host beam. Inductive-capacitive-resistive (LCR) shunted circuits are connected to the piezoelectric patches. A supercell with different LCR shunted circuits is designed. To couple multiple locally resonant bandgaps to Bragg bandgaps, an optimized scheme based on genetic algorithm is designed. The imaginary part of the wavenumber is used as an optimization objective to achieve the maximum attenuation within the target frequency range. The results show that two Bragg bandgaps are bridged to form an ultrawide bandgap and maximum attenuation is achieved. The transmissibility shows that the metamaterial can achieve optimal vibration suppression in the ultrawide frequency range. The finite element results verify that the optimized metamaterial can bridge the two bandgaps into a wide bandgap and can realize optimal vibration suppression at ultrawide frequencies. The pseudo-stochastic vibration of 600–8100 Hz confirms that the optimized metamaterials are more suitable for broadband vibration suppression. This metamaterial has more advantages in complex engineering environments.