Cyclic Loading Performance of Radius-Cut Double Coke-Shaped Strip Dampers

Abstract

Conventional slit dampers are widely used for the purpose of seismic retrofitting, however, the structure of these dampers is susceptible to fractures, due to stress concentration at the ends of the strips in the event of large earthquakes. To address this issue, a novel radius-cut coke-shaped strip damper featuring improved ductility is proposed herein. This damper was developed based on the moment distribution over the strip when both its ends were constrained. The height‑to‑width ratio of the strip was increased to induce bending rather than shear deformation, and the reduced beam section method was employed. A radius-cut section was used to intentionally focus the stress to induce the plastic hinge. This reduced the fracture fragility of the specimen, resulting in an increased inelastic deformation capacity. Cyclic loading tests were conducted to verify damping performance against earthquakes. Experiments and finite element analyses proved that the coke-shaped damper exhibits improved ductility. The final fracture occurred in the radius-cut section after sufficient energy dissipation during cyclic loading. The results also indicated further improvements in strength due to the membrane effect under cyclic loading, caused by the tensile resistance of the strip due to its constrained ends.

Evaluation of the Seismic Performance of Single-Plate Metallic Slit Dampers Using Experimental and Numerical Data

“…Strain gauges were strategically positioned at four specific locations on each damper to acquire essential data pertaining to the performance of the SPMSDs. These locations, based on [26], are recognized as critical areas prone to failure or experiencing high stress concentrations. Figure 6 depicts the exact positioning of the strain gauges on the SPMSDs.…”

“…The experimental data from these tests is then examined to determine the effectiveness of the MSDs in reducing the seismic response of the structure. As an example, through experimental evaluation, Bae et al were able to conclude that increasing the height-to-width ratio of dampers results in reduced structural deformation [26]. Sensors are usually placed at various locations to measure displacement, acceleration, and other important parameters defined and chosen prior to the execution of the experiment.…”

Seismic Resilience of Steel-Braced Frames Incorporating Steel Slit Dampers: A Review and Comparative Numerical Analysis

“…After retrofitting by slit dampers Traditionally used slit dampers are prone to cracking and breaking because of stress buildup at the ends of the strips when used for earthquake retrofitting. Bae et al [101] proposed an improved damper design using radius-cut cokeshaped strips to address this issue and enhance ductility. Figure 19 illustrates the von Mises stress distributions for the three analysis models.…”

Seismic Performance of F3D Free-Form Structures Using Small-Scale Shaking Table Tests

“…To evaluate the seismic performance of the structures, several indicators should b investigated [15][16][17][18]. One of the significant indicators is the story drift of the structure Sommer and Bachmann [19] selected a story drift as one of the indicators for studying th seismic behavior of asymmetric reinforced concrete wall buildings.…”

“…This paper aims to investigate the seismic performance of F3D free-form structure using small-scale shaking tables. To validate the small-scale tests, the similitude laws wer To evaluate the seismic performance of the structures, several indicators should be investigated [15][16][17][18]. One of the significant indicators is the story drift of the structures.…”