Seismic performance and damage evaluation of a reinforced concrete frame with hysteretic dampers through shake‐table tests

Abstract

SUMMARYPassive energy dissipation devices are increasingly implemented in frame structures to improve their performance under seismic loading. Most guidelines for designing this type of system retain the requirements applicable to frames without dampers, and this hinders taking full advantage of the benefits of implementing dampers. Further, assessing the extent of damage suffered by the frame and by the dampers for different levels of seismic hazard is of paramount importance in the framework of performance-based design. This paper presents an experimental investigation whose objectives are to provide empirical data on the response of reinforced concrete (RC) frames equipped with hysteretic dampers (dynamic response and damage) and to evaluate the need for the frame to form a strong column-weak beam mechanism and dissipate large amounts of plastic strain energy. To this end, shake-table tests were conducted on a 2/5-scale RC frame with hysteretic dampers. The frame was designed only for gravitational loads. The dampers provided lateral strength and stiffness, respectively, three and 12 times greater than those of the frame. The test structure was subjected to a sequence of seismic simulations that represented different levels of seismic hazard. The RC frame showed a performance level of 'immediate occupancy', with maximum rotation demands below 20% of the ultimate capacity. The dampers dissipated most of the energy input by the earthquake. It is shown that combining hysteretic dampers with flexible reinforced concrete frames leads to structures with improved seismic performance and that requirements of conventional RC frames (without dampers) can be relieved.

Correlation of Plastic Strain Energy and Acoustic Emission Energy in Reinforced Concrete Structures

“…Figure 21 reflects the same result as in previous tests, namely a very good correlation between and WP until t0, and a divergence of the energies after this point, in very good agreement with Equations (1) and (2). It is worth noting that, besides the good correlation between 0 AE E and WP,0, it is consistently observed that the development of cracks in concrete reduces the fundamental frequency of vibration of the specimen and increments the fraction of damping [14,25,26]. The reduction of the fundamental frequency is due to the decrease of stiffness.…”

Entropy Analysis for Damage Quantification of Hysteretic Dampers Used as Seismic Protection of Buildings

“…Each test model has two levels; the lowest level will be referred to as ground floor and the highest one as first floor herein. A detailed description of the test structures can be found in [54] and [55]. Specimen FD was equipped with four WPDs, two on the ground floor and two on the first floor.…”

Steel slit shear walls with double‐tapered links capable of condition assessment

“…Here, the maximum strength Q max t was defined as the largest absolute strength obtained up to the completion of the 6% drift ratio cycles. The maximum ratio of Q max t /Q y was never greater than 1.5, which indicated that the plastic strength Q p in Equation 4 can be conservatively used in the estimation of maximum strength.…”