Combined attenuation zones of combined layered periodic foundations

Abstract

Layered periodic foundations (LPFs) with identical unit cells have been proposed as a type of seismic metamaterials due to the unique dynamic characteristic of attenuation zones. How-ever, it is difficult to design attenuation zones with both comparatively low starting frequencies and large bandwidths for traditional LPFs with identical unit cells. In this paper, combined layered periodic foundations (CLPFs) are proposed by combining two traditional LPFs with different unit cells in tandem. Combined attenuation zones of the CLPFs are identified by investigating the frequency response functions of the CLPFs. The generation mechanism of the combined attenuation zones was studied by varying the configuration of CLPFs. The results show that the combined attenuation zones are the union of attenuation zones of the two traditional LPFs. To verify the efficiency of CLPFs, the seismic responses of a four-story frame structure with CLPF are simulated. The present work is very helpful for the design of CLPFs with attenuation zones with a low starting frequency and large bandwidth.