Experimental and numerical study of the hybrid hydraulic damper with independent performance in tensile and compressive for improving the seismic performance of braced structures

In this article, a hydraulic damper is introduced to improve the seismic performance of braced structures and control the buckling of braces. This damper consists of a double-acting hydraulic jack, a one-way valve, and a high-stiffness spring, enabling independent operation in both tension and compression. The Hydraulic Damper with Independent Tension and Compression (HDITC) has high initial stiffness and operates based on a hybrid mechanism dependent on displacement and velocity. Damper combination with brace and its independent action, in compression the damper can dissipate energy up to the buckling force of the brace and, in tension, up to the yield force of the brace. To evaluate the cyclic performance of the damper, a laboratory test was developed, and the numerical modeling of the damper was investigated. The HDITC damper has a stable performance similar to the combination of friction damper and viscous damper behavior and effectively producing a full hysteretic behavior under various asymmetric tensile and compressive forces. To investigate how the new damper improves brace behavior, the cyclic behavior of the brace with and without the damper was examined. The results indicated that the use of the damper can increase energy dissipation by up to 7.2 times, depending on the slenderness ratio of the brace. Finally, the seismic behavior of a special braced and buckling restrained frame under earthquake and aftershock excitation was studied, demonstrating that the use of the damper can effectively reduce seismic damage.