New Energy Based Metrics to Evaluate Building Seismic Capacity

Since the advent of Performance-Based Earthquake Engineering (PBEE), increasingly effective methodologies have been investigated in characterizing capacity and identifying collapse, in particular. The possibility of accurately defining a limit state with a number, by means of damage indices, has always shown greater attractiveness, given the intrinsic capacity to simplify a complex problem. In recent years, methodologies based on an energy approach have shown great reliability in characterizing the collapse. A new metric aimed at characterizing damage is presented, developed starting from the idea that it can be represented in a measurable space taking into account simultaneously the internal energy and the internal power. In other words, what is essential in characterizing the damage is not represented only by the energy dissipation, but also the velocity at which the energy is imparted to the structure. The energy, as a measure of plastic work, with its first derivative (power) were used as parameters to build a damage index that would represent the dissipative state of the system in a measurable space. The theory, which was developed starting from a series of simple oscillators, was verified on a sample of experimental tests.