Dynamic analysis of 3D printed lattice sandwich beam with square grid core

Abstract In this paper, the vibration characteristics of sandwich beams with square grid cores are investigated theoretically, numerically and experimentally. The natural frequencies of the sandwich beams are calculated by Euler–Bernoulli theory and equivalent parameters. The theoretical results are validated by using numerical and experimental results. Two simulation methods: equivalent simulation and detailed simulation are used. In the equivalent simulation, the material is assumed to be isotropic with the equivalent material properties. The natural frequencies and mode shapes of 3D-printed sandwich beams are measured using the amplitude-fluctuation electronic speckle pattern interferometry. It is found that filling metal mixture into the cores only changes the equivalent density. The equivalent stiffness is almost the same. Thus, it is possible to control the vibration characteristics of sandwich beams by filling a metal mixture into the cores with almost constant stiffness. Then, the composite sandwich beams with different square grid cores are studied theoretically, numerically and experimentally. The results obtained from different methods are in good agreement with each other. The study offers a method to control the structural vibration characteristics of sandwich beams by changing the design of the square cores and filling the cores with metal mixture.