Research On Band Gap And Damping Property Of Composite Material With Periodic Micro Octagon-like Lattice Structures

With the development of high technology, the materials are often required to have multifunctional properties in the field of science and engineering. The properties of composite materials consisting of two or more different materials can be adjusted by changing the representative parameters of microstructures (the properties of materials', distribution, volume fraction etc.). Periodic micro truss-like lattice structures composite material is a new lightweight multifunctional material, such as:ultra-light, high strength, impact resistance, heat insulation, absorbing, vibration and noise reduction etc., which has a broad application prospect in aerospace, aviation, navigation, transportation and other fields. So far, except our research team, there isn't any other references published about the research on damping property of composite material with periodic micro truss-like lattice structures, which is made by adding damping material or ball into the inter space of periodic micro truss-like lattice structures material.In this paper, taking composite material models with periodic micro octagon-like lattice structures and composite material mass ball models with periodic micro octagon-like lattice structures for example, we researched the band gap and damping property of the models from the infinite and finite periodic structure point of view. The main research contents and results include:(1) For infinite periodic structure material, under the assumption of the viscoelastic damping theory in structural dynamics, using the Floquent-Bloch theory, the wave equations established by the finite element method are reduced to complex coefficient eigenvalue equations of the representative unit cell. From the solution of these equations, the dispersion relation and damping property of damping composite material with periodic micro octagon-like lattice structures was obtained. Results show that the damping property of periodic micro octagon-like lattice structure/ball composite material is better than periodic micro octagon-like lattice structure composite material; to some degree, the larger of the ball's density, the lower of band gap's starting and cut-off frequency, the wider of the band gap's range, the better of the damping performance in OHz-1000Hz frequency range.(2) For finite periodic structure material, we researched its vibration transmission characteristics by harmonic response analysis. Through the simulation, the vibration wave propagation and attenuating behaviors of finite periodic structure was obtained. Results show that the damping property of periodic micro octagon-like lattice structure/ball composite material is better than periodic micro octagon-like lattice structures composite material; to some degree, the heavier of the ball's weight, the lower of band gap's range, and the better of the vibration reduction performance below the first band gap frequency range.In a word, the band gap and damping property of damping periodic composite material is investigated through numerical calculation and simulation. Our research is a kind of theoretical and practical guidance to science and engineering.