Engineered Metamaterials: a Novel Technology for Seismic Protection

Metamaterials are artificially engineered and so boast properties not found in nature. One important application is in earthquake mitigation. In a 'cloaking' process, seismic metamaterials can shield buildings from seismic waves. Professor Tungyang Chen, Department of Civil Engineering, National Cheng Kung University, Taiwan, is working with doctoral student Jun-Hong Lin and former master's student Dian-Kai Guo on research to provide new designs of seismic metamaterials. They are utilising theoretical analyses, numerical modelling – including finite element calculations based on the multiphysics simulation software COMSOL – laboratory-scale experiments and full-scale field tests with the goal of attenuating earthquakes and ultimately protecting buildings and saving lives. A focus for Chen and the team is on shear horizontal waves, or Love waves, and how they can be attenuated by seismic metamaterials. The researchers developed a transversely isotropic model designed to imitate the Earth's geological conditions and were able to assess how Love waves interacted with different resonators and discovered that resonators can be engineered to adjust their frequencies and act as a shield for seismic waves. Chen and the team will extend this line of investigation to include other types of ground motion. The researchers are also developing a tool for seismic cloaking in work that involves designing a material with proper internal structures and material compositions.