Keywords: energy dissipation, dynamic response control, vibro-impact systems, numerical modelling.

Seismic isolation is a passive control methodology widely used for the mitigation of the dynamic response of structures.

However, consistent seismic actions can induce considerable displacements in these structures, which in turn can cause damage to the isolation system or impacts against adjacent structures in the event of insufficient seismic gap [1].

A technique to prevent the occurrence of these negative phenomena can be obtained by interposing dissipative and deformable devices, called bumpers, between the structure and the adjacent ones [2,3].

Therefore, in this work the response, from a numerical point of view, of single degree-of-freedom system isolated at the base subjected to known seismic actions and whose displacements are limited by bumpers has been studied. The system was designed according to an optimal formulation that relates the mechanical parameters of the isolator with those of the bumper, as well as with the seismic gap used [4].

The several scenarios investigated refer to six different seismic gaps, defined in relation to the maximum displacement of the mass in the absence of impact, and are a function of the natural period of the system.

For the typical periods of isolation of the structures, the results show a considerable reduction in displacements compared to a modest increase in accelerations, evidence that highlights the effectiveness of the optimal formulation used.

References

[1]  Polycarpou, P.C., Komodromos, P., "On poundings of a seismically isolated building with adjacent structures during strong earthquakes", Earthquake Engineering and Structural Dynamics , 39(8), page 933-940, (2010).

[2]  Andreaus, U., De Angelis, M., "Influence of the characteristics of isolation and mitigation devices on the response of single-degree-of-freedom vibro-impact systems with two-sided bumpers and gaps via shaking table test", Structural Control and Health Monitoring, 27(5), art. no e2517  (2020).

[3]  Stefani, G., De Angelis, M. Andreaus, U., "Influence of the gap size on the response of a single-degree-of-freedom vibro-impact system with two-sided constraints: Experimental test and numerical modelling", International Journal of Mechanical Sciences, 206, art. no 106617 (2021).

[4]  Stefani, G., De Angelis, M. Andreaus, U., "The effect of the presence of obstacles on the dynamic response of single-degree-of-freedom systems: Study of the scenarios aimed at vibration control", Journal of Sound and Vibration, art. no 116949 (2022), In Press.