Numerical Modeling of Single-Storey Precast Frame’s Pinned Connections With a Special Damper

Abstract

Single-storey precast frames with pinned beam-column connections are widely used in Turkey. This type of precast structures had suffered extensive damages during the recent major earthquakes (Ceyhan (1998), Kocaeli (1999), Duzce (1999). The damages had been generally concentrated on the pinned connections as failure of dowels or at the column bases as large plastic deformations.A special lead extrusion damper (LED) has been developed in an ongoing PhD study in Istanbul Technical University. The damper is going to be installed into the pinned connection regions of the single storey precast frames.Nearly half scaled specimens representing existing features of precast frames are planned to be tested on the shake table. Prior the experimental work, an extensive blind prediction study has been carried out through the nonlinear dynamic time history analyses of the numerical models which are representing the specimens with and without damper. The numerical models are generated with Seismostruct. The comparison of the structural behaviors between the bare frame and the frame with LED has been discussed. Although the relative drifts of the precast frame has been significantly reduced, the observed base shear demand moderately increased by the installation of the LED.

Design and Experimental Assessment of a Prestressed Lead Damper with Straight Shaft for Seismic Protection of Structures

“…The HF2V technology was practically employed in the Kilmore Street Medical Center in New Zealand, where the HF2V devices were used to develop a hybrid system, called the "Advanced-Flag Shape" system, to allow controlled rocking of the structure [27]. Further research on this technology was carried out by Soydan [14][15][16][17], Patel [36,37], Yang [37,38] and Quaglini [10,11]. The application of HF2V devices in structural connections of both precast structures and steel structures was studied in [29,33,35].…”

“…The damper dissipates the input energy through the friction activated between a lead core and a steel shaft and achieves high specific dissipation capability through prestressing the working material. Differently from lead dampers proposed in the past [13][14][15][16][17][18], the operation of the novel device, which is called the prestressed lead damper with straight shaft (or PS-LED), is based on friction solely and does not exploit the extrusion of lead through an orifice, which mitigates the cyclic degradation of the response, eases the design and the construction and reduces production costs. The performance of the damper is assessed experimentally to evaluate the damping capability and the robustness during repeated cycles and to verify the compliance with the requirements of the European standard EN 15129 for displacementdependent devices [19].…”