Research On Band Gap And Damping Property Of Periodic Micro-parallelepiped Lattice Composites

With the development of modern technology, periodic truss structural material, which has a broad application prospect in the field of transportation, machinery, construction and so on, has been paid more and more attention. It has many excellent qualities, such as energy absorption and vibration reduction, etc. In this study, band gap and damping property of periodic composite with micro-parallelepiped structures are researched. Meanwhile, in order to improve the damping characteristics, a sphere was embedded into the center of micro parallelepiped structures. Periodic micro-parallelepiped lattice composites is constructed by adding damping materials and embedding spheres into the inner space of periodic micro-parallelepiped lattice structures. In this paper, we analyzed the band gap and damping characteristic of periodic micro-parallelepiped lattice composites models from the two aspects of infinite and finite period. The main research contents and results include:On the one hand, the unit cell models of infinite periodic micro-parallelepiped lattice composites are established. Using the Floquet-Bloch theory, the periodic boundary condition is introduced with the assumption of linear viscoelastic damping theory and proportional damping. By programming and solving in MATLAB, the dispersion relation and damping property of periodic micro-parallelepiped lattice composites are obtained. It shows that periodic micro-parallelepiped lattice composites with spheres has better damping property. What’s more, the larger of radius and density of the sphere are, the lower of starting and cut-off frequencies of the first band gap are, the wider the band gap range is, the better of the damping performance is.On the other hand, the finite periodic micro-parallelepiped lattice composites models with20x20x20periods are established. By harmonic response analysis, the vibration transmission property is researched and the vibration wave propagation and attenuating behaviors of the models are simulated. Results show that periodic micro-parallelepiped lattice composites with spheres has better damping property. To some degree, the larger of the radius of the sphere is, the lower the range of the first band gap is, and the better the vibration reduction performance is. By structural design, theoretical derivation and simulation, the band gap and damping property of periodic micro-parallelepiped lattice composites is researched. It is a guidance for further research and application of lattice composites.