Two-Dimensional Finite-Element Simulation of Periodic Barriers

AbstractA novel kind of seismic isolation technique called “Periodic Barriers,” which combines trench-type wave barriers and metamaterial, is introduced in this research. Metamaterial possesses a unique frequency-selective property that enables the metamaterial to manipulate the wave propagation. By infilling the metamaterials in the trench-type wave barriers, the periodic barriers are expected to display advantages of both the wave barriers and the metamaterials. The two-dimensional (2D) finite-element (FE) simulation is conducted to study the performance of the barriers adapting the metamaterial. This FE model is validated with the experiment on the metamaterial-based foundation. The convergence test on mesh size with different element types are investigated, and the minimum mesh size and property element type are determined for simulating the behavior of metamaterial. To simulate the unbounded domain, the absorbing boundary is implemented to eliminate the reflection from the boundaries. The dynamic responses obtained from models with infinite element boundary and viscoelastic boundary are found to converge with the increasing model size. To boost the computing efficiency, two analysis methods (fix-frequency harmonic analysis, and the time-history analysis) are adopted and found to have a strong correlation with each other. Based on the proposed modeling techniques and the analysis methods, the simulation of the periodic barriers embedded in the soil is performed. With various loading distance and the number of periodic barriers, the performance of the periodic barriers is found to comply with its theoretical frequency band gaps.