Experimental tests on a dissipative device based on U-shaped plates for seismic isolation systems

Seismic isolation systems often needs of auxiliary dissipation devices in order to limit the forces transmitted to the superstructure and, most of all, in order to reduce the maximum displacement of the system. Such auxiliary devices should be simple to design and to realize, inexpensive and easy to replace. In this work, the behaviour of a dissipative device equipped with U-shaped steel plates is studied, such device dissipates energy by the means of the inelastic behaviour due to the bending of the plate. The principle of working and some simple design formulae to define the principal characteristics of the device are described. The results of an experimental test campaign executed on a dissipative device based on U-shaped plates according to EN15129 are shown. By using the data provided by such experimentation, the performances of the device and its effectiveness as auxiliary damper are commented. Finally, some critical observations about the effectiveness of the available design formulae are carried out.