An Innovative Steel Damper with a Flexural and Shear–Flexural Mechanism to Enhance the CBF System Behavior: An Experimental and Numerical Study

Abstract

An innovative passive energy damper is introduced and studied experimentally and numerically. This damper is designed as the main plate for energy absorption which is surrounded by an octagon cover. In addition to simplicity in construction, it can be easily replaced after a severe earthquake. Experimental test results, as well as finite element results, indicated that, by connecting the cross-flexural plate to the main plate, the mechanism of the plate was changed from flexural to shear. However, the cross_flexural plate always acts as a flexural mechanism. Changing the shear mechanism to a flexural mechanism, on the other hand, increased the stiffness and strength, while it reduced the ultimate displacement. Comparing the hysteresis curve of specimens revealed that models without cross_flexural plates had less strength and energy_dissipating capability than other models. Adding the flexural plate to the damper without connecting to the main plate improved the behavior of the damper, mainly by improving the ultimate displacement. Connecting the cross plate to the web plate enhanced the ultimate strength and stiffness by 84% and 3.9, respectively, but it reduced the ductility by 2.25. Furthermore, relationships were proposed to predict the behavior of the dampers with high accuracy.

Performance Improvement of Innovative Shear Damper Using Diagonal Stiffeners for Concentrically Braced Frame Systems

“…Based on [23,24], it is assumed that the ultimate strength of the flange plate using the plastic theory is given when the flexural hinges are formed at the two ends of the flange plates. Therefore, V f is obtained as…”

“…Among the available dampers, metallic dampers are more economical than others, which is achieved through the inelastic deformation of the metallic material [15]. Various metallic dampers have been proposed to enhance the behavior of the CBF systems, including TADAS [16][17][18], ADAS [19], slit damper [20,21], and shear dampers [22][23][24]. These devices have mainly been designed to be incorporated into the bracing systems of structural frames.…”

Prediction of steel plate-based damper for improving the behavior of concentrically braced frames based on RSM and ML approaches for sustainable structures

“…To enhance the performance of CBFs, steel plate-based dampers are often incorporated into the system 3 . These dampers consist of steel plates that are bolted to the building's columns and beams 4 . The plates act as shear walls, providing additional stiffness and strength to the structure 1 .…”

“…P-Delta Effects: CBFs are susceptible to P-Delta effects, which refer to the second-order effects caused by the combination of axial loads and lateral displacements. These effects can lead to additional moments and forces in the structure, affecting its overall stability and behavior 4 . Proper consideration of P-Delta effects is essential in the design of CBFs.…”

Improving the behavior of concentrically braced frame braces using a flexural damper: Experimental and numerical study

“…During the last decades, some ideas have been formulated to develop and improve the behavior of the CBF system. Examples of the various proposed metallic dampers include the following: Added Damping and Added Stiffness (ADAS) 6 ; Triangular ADAS 7 ; shear-flexural dampers, 8,9 shear-flexural yielding hinges in the central yielding dampers, 10 shear dampers that typically come in three types; vertical shear link, 11,12 links that are indirectly 13,14 or directly 15,16 attached to the diagonal member of CBF; U-shaped damper 17 ; and BRB system. 18,19 Although majority had shown good performance in labs and numerical studies as well as in past earthquakes, the main problem in most proposed damping devices is their high cost when applied in small to moderate structures.…”