Evaluation of the seismic response of frames implemented with metamaterials

Abstract

This research aims at introducing a new idea in the design of frames to eliminate or suppress the transmission of waves through the structure in a certain designated range of frequencies that is called hereinafter as frequency band gap. To achieve this goal, we apply a concept from the mechanics of metamaterials to the investigated structural system by proposing a new beam-column connection in a multistory 2D frame. Modal and harmonic analysis are carried out for both the new proposed frame and the ordinary one in order to investigate the response of both systems. A thorough time history analysis is applied, also we demonstrate the response of the new proposed model under the loading of 9 different earthquake loads and a comparison between the resulted displacement and base shear is performed. Furthermore, a realization of the new connection is demonstrated. Results, comparison, and discussion are presented. The results show that the new proposed frame exhibits the calculated frequency band gap and the effect of seismic waves with frequencies within the bandgap frequency range was significantly mitigated. The novelty of this research is the ability of the new proposed idea to generate and tailor a frequency band gap in order to prevent the transmission of waves in this range of frequencies through the structural system itself. Consequently, the bandgap range of frequencies for each structure can be tuned depending on the seismic risk of its region on the global scale. This new feature could have a great impact and significant application to mitigate the effects of seismic waves on a structure.

Keywords

• Frequency band gap
• Metamaterials
• Vibration
• Waves
• Modal analysis
• Harmonic analysis