An inerter-enhanced asymmetric nonlinear energy sink for response mitigation of structures subjected to harmonic and seismic ground excitations

To improve the applicability of mass dampers in control problems facing different types of uncertainties, asymmetric nonlinear energy sink-inerters (ANESIs) are proposed. Previous studies reveal that ANESIs have excellent control effect in mitigating impulsive responses but only briefly touch upon their seismic application. This study is intended to provide better understanding in this regard by analyzing the dynamics of the ANESI system when subjected to harmonic and seismic ground excitations. First, the development of ANESIs is described and the theoretical model of ANESIs is updated in accordance with the experimental validation on a three-story steel-frame structure. Then analytical investigations are carried out and subsequently a design method is proposed for the ANESI system when subjected to harmonic ground excitation. Finally, 12 seismic ground motions are applied to the ANESI system to assess its control effectiveness, energy and frequency robustness, and space demand. The results show that devices with inerter are in general more effective than those without inerter and the ANESI outperforms its linear and nonlinear counterparts with stronger robustness against changes in structural property and energy level, demonstrating great potential in seismic application.

Automated summary

This study proposes asymmetric nonlinear energy sink-inerters (ANESIs) to improve the applicability of mass dampers in control problems facing different types of uncertainties. Analyzing the dynamics of the ANESI system under harmonic and seismic ground excitations, the study updates the theoretical model of ANESIs, carries out analytical investigations, and proposes a design method for the ANESI system. Results show ANESIs outperform linear and nonlinear counterparts in seismic applications.