Low-cyclic fatigue consideration in terms of damping parameters optimization in seismic isolation systems

Grounds and foundations, underground structures

The article touches upon an algorithm of aimed parameters of the plastic damping development in seismic isolation systems taking into account low-cyclic fatigue. All the phases of damper bars plastic resource determination in the shuttle-type plastic damping seismic isolation systems have been considered. They include: solution to a dynamic problem of non-stationary seismic influences of a various level and duration; definition of a number of loading cycles; distribution of number of loading cycles with various level of movements; transition from movements to maximum deformations; establishment of an allowable number of cycles and a plastic resource of a core by Koffina – Menson and Palmgrema – Maynera's criteria. Also, it has been proved that the required plastic resource can be provided by means of geometry variation (length and section size of core) and number of bars alteration.