Experimental study on the response of seismically isolated masonry infilled steel frames during the initial stages of a seismic movement

A novel seismic isolator is presented to detach the structural behavior from the infill effect during earth movements, with the aim of avoiding strong interactions. An experimental campaign was carried out to determine the influence of this isolator during the early stages of the seismic response of masonry-infilled steel frames, testing different configuration schemes to assess their effectiveness in terms of overall isolation, reduction of peak loads, strain levels and energy dissipation. The device was found to hinder the formation of the damaging diagonal compression struts by absorbing the relative displacements between frame and infill. The results achieved show that seismic interaction between infill panels and the structural skeleton can be faced from an isolation point of view.