Master the mass summary, and you master the seismic response of your structure in ETABS.
For professional design reports, you can right-click the table and select . This allows you to create charts showing the mass distribution over the building height, which is a great visual aid for client presentations or calculation packages.
of the center of mass for that specific story. ETABS calculates this by finding the weighted average of all mass points on that floor. etabs mass summary by story
A quick glance at the cumulative mass helps verify if you are working in kips, tons, or kilograms. C. Calculating Eccentricity
The total mass accumulated from the top story down to the current story. The value at the base story represents the total seismic mass of the structure. Translational Mass vs. Rotational Mass Master the mass summary, and you master the
Before designing lateral systems, you must calculate the Seismic Response Coefficient ($C_s$). This requires the total seismic weight ($W$).
Seismic lateral forces are directly proportional to mass ( of the center of mass for that specific story
Understanding ETABS Mass Summary by Story: A Complete Guide Verifying the mass distribution of a structure is a critical step in seismic and dynamic analysis. In ETABS, the table provides a centralized, standard report of how mass is distributed vertically across your model. Accurately assessing this data ensures your lateral load patterns, base shear calculations, and dynamic modal behaviors are correct. Why Story Mass Summary Matters
Mass Moment of Inertia. This represents the resistance of the story mass to rotational acceleration about the vertical Z-axis passing through the Center of Mass.