High performance materials for pendulum sliding bearings

At Politecnico di Milano a novel thermoplastic material for pendulum bearings operating in seismic isolation of buildings and structures has been recently developed. The material properties were characterized in small scale tests, and the dependence of the coefficient of friction on operating conditions like pressure, temperature and velocity was determined at speeds and durations typical of seismic events. The effect of extended durations of excitation on the stability of friction was assessed. Two prototypes of pendulum bearing operating with the new material were manufactured and tested. The results confirmed the good performance of real scale isolators in terms of low horizontal stiffness, high damping and good stability of the dynamic properties