DEVELOPMENT OF A METAMATERIAL PERIODIC FOUNDATION FOR SEISMIC PROTECTION

摘要

One of the most recent and interesting research topics of structural seismic protection nowadays is the use of seismic metamaterials. The idea is based on the concept of phononic crystals or in another term the attenuation of propagating waves due to the periodic distribution of materials. There are different types of seismic metamaterials under study such as periodic void inclusion, periodic rigid inclusion, Metaforest that is considered as a natural seismic metamaterial and seismic isolation by using periodic foundation which is the subject and locus of this paper. Phononic crystals concept produces frequency band-gaps at different levels that are related to geometrical, physical and mechanical properties of arranged materials. Therefore, each propagating wave with a frequency within attenuation range will be blocked due to the local resonance phenomenon. The following research attempts to present the evolution of metamaterial periodic foundation system designed for seismic protection and the analysis of fundamental theory and methods of periodic materials. Finite element method is also employed and dynamic responses of a frame structure with periodic foundations are compared. Moreover, a parametric analysis is carried out to highlight on the influence of different geometrical, physical and mechanical parameters of the composite periodic foundation on the attenuation zone properties. In conclusion, this study proves that this seismic isolation concept has the potential to significantly reduce the seismic risk which in turn confirms the validity of the proposed metamaterial periodic foundation.