Modelling the uncertainty in the response of a base isolator

Base isolation is a “decoupling” of the structure from the vibration source. It is obtained by the insertion of a soft mechanical device, usually located between the structure and its foundations. Such an object filters the motion which does not propagate to the upper system.This paper is focused on an innovative concept of base isolator where the device is realized by a special geometry of metallic bars. They are made in a Cu-based shape memory alloy (SMA). Such an alloy also ensures energy dissipation by the hysteresis which characterizes its super-elastic constitutive law.The response of the device is first predicted by a numerical model built within a commercial finite element code which offers an idealization of the alloy constitutive law. Improved models and model uncertainty are then identified from the results of suitable laboratory tests.