Research Projects

Protecting structures and critical components from vibration is essential from both safety and serviceability perspectives. This project aims to develop and optimize periodic metamaterial systems that can act as low-frequency vibration shields for structural engineering applications. Metamaterials are engineered materials featuring carefully designed unit cell structures arranged in periodic patterns. Band gaps in these structures can occur through either Bragg scattering or local resonance. Bragg scattering occurs when the characteristic unit cell length is comparable to the wavelength in a periodic structure, while resonant band gaps are due to the inclusion of resonators within the unit cell. Metamaterials can effectively attenuate specific vibration frequencies by appropriately combining Bragg and resonant band gaps. This property enables advanced vibration filtering applications across various fields, including civil and aerospace structures. The research focuses on enhancing the understanding of how different unit cell configurations interact with mechanical waves, which has not been explored well. Innovative unit cell designs and periodic arrangements will be studied in detail to achieve specific band gap characteristics. These structures will be analyzed using analytical dispersion relations. This can be derived from the equation of motion of a unit cell coupled with the Floquet-Bloch boundary conditions. Detailed finite element models of the full periodic structure will verify these dispersion characteristics. Subsequently, a detailed meta-heuristic optimization framework will be proposed for designing these unit cells. The study also aims to demonstrate the effectiveness of these developed systems in the laboratory by fabricating several optimal metamaterial configurations and testing them under various types of vibration loading. This project has significant practical importance. The filtering capability of periodic metamaterial will have immense application in protecting critical infrastructure, such as power plants, military installations, etc., against undesirable ground vibration, including seismic motion. The technique can also stop vibration transfer from railway tracks and machinery into adjacent structures. By exploring new uses for metamaterials in controlling vibrations, this research could change how low-frequency vibrations are filtered. These advancements will eventually open up new opportunities for protecting critical structures.