Determination of the Resonant Frequency of the Anti-Vibration Metamaterial Under Sinusoidal and Noise Signal Excitation—Analysis of Experimental and Numerical Results

The properties of metamaterials depend not only on the material from which they are made, but also on the structure in which they are formed. This property makes it possible to search for new technical applications for existing materials that in their basic form do not exhibit the expected properties or have them to an insufficient degree. The article presents the results of experimental and numerical studies involving the determination of the resonant frequency of a selected anti-vibration metamaterial. The research was aimed at comparing the resonant frequencies determined from laboratory tests using a mechanical vibration inductor with the results of a numerical simulation based on the finite element method (FEM). Laboratory experimental studies involved recording the amplitude-frequency response in the range of 1–400 Hz of a metamaterial loaded with a test mass to two types of excitation: a sinusoidal signal and a noise signal. Numerical studies consisted of developing a numerical model of the anti-vibration metamaterial, and then using it to carry out numerical analyses that included the determination of vibration modes and frequency responses. The established boundary conditions made it possible to compare the obtained results of the numerical analyses with the results of laboratory experimental tests. Comparison of the results of the two tests showed their satisfactory agreement. The relative difference in the determined values of resonant frequencies during laboratory tests and numerical analyses did not exceed 6%. Satisfactory agreement between the results of simulation and laboratory tests was obtained by comparing the values of vibration acceleration and displacement occurring during resonance. The results of the study showed that the developed simulation model reflects well the behavior of the studied metamaterial subjected to mechanical vibrations. Numerical simulations can be useful in the design and modification of metamaterials.