Design and numerical simulation of seismic metamaterials with Love waves in transversely isotropic media

• Main Authors: Dian-KaiGuo, 郭典愷
• Other Authors: Chung-Chan Hung
• Format: Others
• Language: en_US
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/ectze7

碩士 === 國立成功大學 === 土木工程學系 === 107 === We investigate the propagation of shear polarized surface wave, in the form of Love waves, with mechanical resonators on the top of semi-infinite layered media. Both the top soft guiding layer and the semi-infinite substrate, are taken to be transversely isotropic, in a simulation of a type of surface wave in the seismic ground motion of the Earth. In addition, the effect of initial stresses in the soft layer is also examined. The objective of this work is to explore the possibility to control the Love waves dispersive behavior by varying the properties of transversely isotropic phases and the resonators mechanical parameters. We also perform 3D finite element simulations to demonstrate the performance of effects. The results suggest that transverse isotropy has little influences on the width of bandgaps, but is sufficient to control the propagation behavior of Love waves with specific values of shear moduli. It is also observed that when the depth of seismic metamaterials is extended to the half-space from the top surface, that is, the height of resonators nearly equals to the thickness of the upper soft guiding layer, the magnitude of displacement fields on the surface in the protected area can be significantly attenuated.