The seismic design rules currently recommended by modern codes are based on the so-called capacity design principles, which allow damage to occur in the ductile parts of the structure, such as beam ends. Therefore, in the aftermath of design earthquakes, plastic deformations at member or connection level will imply high repair costs. Innovative structural solutions to reduce the damage in the structure have been proposed in the last decades. In particular, the so-called supplementary energy dissipation strategy allows to increase the dissipative capacity of structures equipping it with special damping devices. In case of substitution of dissipative zones with dissipative devices the strategy takes the name of substitutive strategy. This is the case of Moment Resisting Frames (MRFs) investigated in this paper, where traditional dissipative zones, i.e. beam ends have been equipped with innovative free from damage frictional devices called FREEDAM dampers. However, the current version of EC8 does not provide any guidelines for the design of MRFs equipped with this type of friction joints. For this reason, in this paper two new design criteria for this structural system are proposed, where the first one is based on the application of the beam-to-column hierarchy criterion (BCHC) while the second one exploits the Theory of Plastic Mechanism Control (TPMC), used with the scope to design structures exhibiting at the collapse a mechanism of global type. A comparison between both the design approaches and the results of the new rules are herein examined by means of nonlinear static analyses.
Comparison Between Different Design Strategies for FREEDAM Frames
MONTUORI, Rosario;NASTRI, ELIDE;PILUSO, Vincenzo;Streppone Simona;
2017-01-01
Abstract
The seismic design rules currently recommended by modern codes are based on the so-called capacity design principles, which allow damage to occur in the ductile parts of the structure, such as beam ends. Therefore, in the aftermath of design earthquakes, plastic deformations at member or connection level will imply high repair costs. Innovative structural solutions to reduce the damage in the structure have been proposed in the last decades. In particular, the so-called supplementary energy dissipation strategy allows to increase the dissipative capacity of structures equipping it with special damping devices. In case of substitution of dissipative zones with dissipative devices the strategy takes the name of substitutive strategy. This is the case of Moment Resisting Frames (MRFs) investigated in this paper, where traditional dissipative zones, i.e. beam ends have been equipped with innovative free from damage frictional devices called FREEDAM dampers. However, the current version of EC8 does not provide any guidelines for the design of MRFs equipped with this type of friction joints. For this reason, in this paper two new design criteria for this structural system are proposed, where the first one is based on the application of the beam-to-column hierarchy criterion (BCHC) while the second one exploits the Theory of Plastic Mechanism Control (TPMC), used with the scope to design structures exhibiting at the collapse a mechanism of global type. A comparison between both the design approaches and the results of the new rules are herein examined by means of nonlinear static analyses.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
