Saman Fernando

The Influence of Key Design Parameters on the Cyclic Axial Behavior of Innovative Replaceable Buckling Restrained Fuses (RBRFs)

ABSTRACT behaviorA detailed parametric study was conducted to determine the influence of the key parameters affecting the cyclic axial of replaceable buckling restrained fuses (RBRFs). These RBRFs are developed for use in damage-resistant moment-resisting connections. A sufficiently low ratio of maximum compressive force to maximum tensile force () at the RBRFs needs to be achieved so that the force transferred to other elements is not excessive. The parameters having a significant influence on this ratio were identified as the ratio of external diameter to fuse diameter and the thickness of the unbonded layer and its shape at the transition zone.

The Effect of Consecutive Earthquakes on a Composite Structure Utilising RBRFs

Low-damage technologies have been developed in recent years which limit the damage imposed on structural elements when a building is subjected to a very rare earthquake event. This has been achieved by a capacity design approach applied to the connections in which the ductile part of the connections yields and all other structural elements remain elastic. Examples of low-damage connections are the sliding hinge joint in steel buildings and variations associated with this, and a combination of a post-tensioning system and mild steel dissipater in precast concrete and timber buildings. A system developed by the authors uses replaceable buckling restrained fuses (RBRFs) that do not require a post-tensioning system to be used conjointly. This system has been studied both experimentally and numerically. This paper considers the use of RBRFs as an energy dissipation device installed at beam-column connections in composite moment-resistant frames. These RBRFs could be replaced after a major event, and hence would cause little disruption. A 2D building frame has been modelled for a case study and its behaviour under 100-year, 500-year and 2500-year return period earthquake events has been summarised. A consecutive earthquake with a return period of 500 years or 2500 years has been applied to the building following both 500-year and 2500-year return period earthquake events. This study was performed since there is a possibility that the consecutive earthquake would occur prior to the replacement of the RBRFs. The results show that the building could still sustain the consecutive earthquakes with little additional residual displacement.