Damping Ratio Selection for Seismic Calculation of Steel Structures
2025-10-07 
90
For calculations under frequent earthquakes:
When the building height is less than or equal to 50m, the damping ratio may be taken as 0.04.
When the building height is greater than 50m but less than 200m, the damping ratio may be taken as 0.03.
When the building height is greater than or equal to 200m, the damping ratio should preferably be taken as 0.02.
If the seismic overturning moment resisted by the eccentrically braced frames exceeds 50% of the total seismic overturning moment of the structure, the damping ratio specified in Item 1 above may be increased by 0.005.
For elastoplastic analysis under rare earthquakes, the damping ratio may be taken as 0.05.
