Topology optimization of metasurfaces for anomalous reflection of longitudinal elastic waves

A numerical method based on topology optimization is developed for designing a metasurface that anomalously reflects longitudinal elastic waves. While the analysis and design of metasurfaces and metamaterials have received much attention recently, no numerical method to design elastic metasurfaces for anomalous reflection has been explored. Here, we formulate a density-based topology optimization suitable for finding a set of phase-delaying unit...