Innovative solutions in Earthquake Engineering are pushing the boundaries towards the design of seismic-resilient structures able not only to meet the life safety requirements, but also to overcome rare earthquakes with limited damage, thus reducing repair costs and downtime. Self-Centering Dissipative (SCD) systems represent an efficient solution to meet this goal, thanks to their capacity to reduce structural damage and avoid residual drifts. Although the performance benefits have been widely demonstrated, their application in practice is still limited due to the lack of general methodologies and code provisions regarding their design and use. Featuring a distinctive flag-shaped hysteresis behaviour, SCD systems exhibit reduced energy dissipation capabilities compared to conventional non-linear systems. This may lead to high displacement and acceleration demands, making conventional design assumptions inapplicable and unsafe. Within this context, determining the relationship between the inelastic demand of SCD systems and equivalent linear systems with the same initial stiffness and damping ratio is a key aspect of the definition of simplified design procedures. The present study performs a parametric analysis on SCD Single Degree of Freedom (SDoF) systems with various hysteretic properties as defined by the initial stiffness, post-yielding hardening, energy dissipation capacity, and displacement ductility. For each configuration, non-linear time-history analyses are performed in Opensees with a set of 240 ground motions scaled to reach a target ductility value, while evaluating the influence of the hysteretic properties on the statistics of the demands. Moreover, constant-ductility spectra are defined in terms of displacements and accelerations. The results inform methods for predicting the seismic demands for SCD systems based on the equivalent elastic system, which is useful information for the definition of simplified design procedures.
PARAMETRIC ANALYSIS ON THE SEISMIC RESPONSE OF SELF-CENTERING DISSIPATIVE SDOF SYSTEMS
Freddi F.;Latour M.;
2024
Abstract
Innovative solutions in Earthquake Engineering are pushing the boundaries towards the design of seismic-resilient structures able not only to meet the life safety requirements, but also to overcome rare earthquakes with limited damage, thus reducing repair costs and downtime. Self-Centering Dissipative (SCD) systems represent an efficient solution to meet this goal, thanks to their capacity to reduce structural damage and avoid residual drifts. Although the performance benefits have been widely demonstrated, their application in practice is still limited due to the lack of general methodologies and code provisions regarding their design and use. Featuring a distinctive flag-shaped hysteresis behaviour, SCD systems exhibit reduced energy dissipation capabilities compared to conventional non-linear systems. This may lead to high displacement and acceleration demands, making conventional design assumptions inapplicable and unsafe. Within this context, determining the relationship between the inelastic demand of SCD systems and equivalent linear systems with the same initial stiffness and damping ratio is a key aspect of the definition of simplified design procedures. The present study performs a parametric analysis on SCD Single Degree of Freedom (SDoF) systems with various hysteretic properties as defined by the initial stiffness, post-yielding hardening, energy dissipation capacity, and displacement ductility. For each configuration, non-linear time-history analyses are performed in Opensees with a set of 240 ground motions scaled to reach a target ductility value, while evaluating the influence of the hysteretic properties on the statistics of the demands. Moreover, constant-ductility spectra are defined in terms of displacements and accelerations. The results inform methods for predicting the seismic demands for SCD systems based on the equivalent elastic system, which is useful information for the definition of simplified design procedures.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
