Experimental assessment of a disc spring–supported seismic friction damper (DSS-SFD) for reinforced concrete structures

This study presents the development of a disc spring–supported seismic friction damper (DSS-SFD) aimed at mitigating earthquake-induced structural damage and potential loss of life in reinforced concrete structures. Quasi-static loading tests were conducted based on the number of cycles and displacement values specified in BS EN 15129:2009 (2009). For comparative evaluation and to highlight the differences from the proposed device, a conventional seismic friction damper (SFD) was also tested under identical conditions. In addition, the influence of DSS-SFD dampers on the seismic performance of hypothetical existing reinforced concrete buildings was evaluated in accordance with the Turkish Building Earthquake Code 2018 (TBEC 2018). The contribution of the DSS-SFD device to the residual story drift ratio of the structure was also investigated by comparison with the SFD device. Within the experimental program, pre-tension forces were applied to both DSS-SFD and SFD devices using bolt torques of 50 Nm, 100 Nm, and 200 Nm (torque sets). Force–displacement responses were experimentally obtained and compared at 25%, 50%, and 100% of the design displacement ( d b d ). The experimental results showed that sliding forces remained constant in the SFD, whereas they increased with displacement in the DSS-SFD. Variations in loading velocity, period, and frequency had no significant effect on the force–displacement relationship. Performance assessment of the existing reinforced concrete structure showed that 83.33% of ground-story columns and 16.67% of second-story columns failed to meet the life safety performance level. After DSS-SFD implementation, all columns and beams satisfied the life safety requirements. The DSS-SFD–retrofitted structure also exhibited a 34.39% lower residual story drift ratio at the base floor than the SFD-retrofitted structure under the selected earthquake record. Overall, the DSS-SFD system enhanced seismic performance and reduced residual story drift.