Numerical Study of Key Parameters Affecting the Behavior of Elliptical Roller Dampers for Using in Seismic Isolators

Yielding dampers are widely regarded as an effective method for reducing the destructive effects of earthquakes due to their high energy absorption capability and enhancement of structural stability. Elliptical roller damper integrates rollers into the conventional elliptical damper that is a yielding type, enabling it to sustain substantial gravity and vertical earthquake loads, and alleviates the dead load imposed on other components within the gravity load-bearing system. In this study, the performance of the elliptical roller damper, as an optimized example of such dampers, was investigated. Using numerical modeling in Abaqus software, the effects of geometric parameters such as length, width, thickness, height, and the number of rollers on the damper's performance were analyzed. The results showed that increasing the width and thickness and reducing the height significantly improved the energy absorption capacity and lateral strength of the damper, while increasing the length and number of rollers had no effect on the hysteresis curve but contributed to the stability of the damper under gravity loads. Furthermore, the elliptical roller damper demonstrated stable hysteresis loops in various loading angles, indicating its capacity to withstand different directions of loading. Finally, an optimized design for using this damper in seismic isolators was proposed, which is expected to effectively reduce the transfer of seismic energy to the structure and enhance its overall stability.