Seismic Performance of Friction-Damped Steel Structures Under Endurance Time Excitation Functions

The use of friction dampers as devices for energy absorption and dissipation plays a significant role in reducing damage to structural load-bearing elements. One of the oldest and most widely used types of these dampers is the Pall friction damper. A key feature in the design of this category of dampers is determining their slip force. A structure equipped with these devices can exhibit behavior similar to braced frames at high slip force levels, or resemble moment-resisting frames at lower slip force levels. Although selecting an optimal slip force for a specific hazard level may yield desirable responses at that level, the system's performance under earthquakes of lower or higher intensities may not be satisfactory. Using the Endurance Time method, the number of required analyses for specific hazard levels can be reduced, and even with a single analysis, the structural response under multiple hazard levels can be evaluated. In this study, a ۹-story steel moment-resisting frame, designed according to building codes, was equipped with Pall friction dampers and evaluated using OpenSees software. This resulted in up to a ۶۰% reduction in structural displacement responses. However, the base shear response showed varying behavior across different hazard levels and was not necessarily increasing or decreasing.

کلیدواژه ها:

Friction damper ، Pall damper ، Slip load ، Endurance Time Method ، Hazard levels ، Passive control of steel structures