Semi-analytical study on low-frequency bandgap of lightweight corrugated-core sandwich meta-plate using spectral element method

In this paper, the elastic wave propagation and low-frequency bandgap characteristics of a lightweight high-strength corrugated-core sandwich meta -plate (CSMP) with local resonators under simply supported boundary conditions is studied. Based on the spectral element method, a non-equivalent high-precision theoretical wave dynamic model of CSMP is established to calculate the band structure and transmission characteristics of the structure. The low-frequency bandgap generation mechanism is revealed and the comprehensive performance of the proposed CSMP is compared with that of the typical sandwich metastructures. Numerical calculation and experimental tests are conducted to verify the proposed theoretical model. Results show that the proposed CSMP with only 1.77% mass ratio local resonators can exhibit a low-frequency bandgap, demonstrating significant flexural waves attenuation and excellent vibration isolation performance. The starting and cutoff frequencies of the low-frequency band gap are mainly attributed to the vibration coupling of the local resonator with the connecting plate and corrugated-core sandwich plate respectively. The prediction results of the theoretical model are consistent with those of numerical simulation and experimental test, which verifies the correctness of the proposed theoretical model. The flexural wave bandgap can be effectively adjusted by reasonably changing the design parameters of the CSMP.