When you use ETABS for high-rise or complex structures, simply looking at the total mass isn't enough. You need to ensure the distribution aligns with the structural intent. Why Mass Summary by Story Matters
Check if you applied property modifiers (like 0.0 weight) to certain elements.
Confirm the inclusion of the appropriate percentage of live loads. etabs mass summary by story better
For better results, your "Mass Source" definition should follow these industry standards:
Mass moments of inertia; critical for capturing torsional effects. When you use ETABS for high-rise or complex
The Center of Mass coordinates; compare these to the Center of Rigidity. How to Improve Your Mass Source Setup
Architects often provide cladding as a line load. Ensure these are applied to the perimeter beams and that the mass source is set to include "Specified Load Patterns." Confirm the inclusion of the appropriate percentage of
Seismic forces are calculated based on mass. If your story mass is off, your base shear and lateral forces will be incorrect. This table allows you to: Verify the self-weight of slabs, beams, and columns.
Detect "ghost mass" from accidental double-counting or modeling errors. Accessing the Data To find this specific table after running an analysis: Navigate to the . Expand Tables > Analysis Results > Structure Results . Right-click Mass Summary by Story and select Show Table . Key Columns to Analyze Significance UX / UY The total translational mass in the X and Y directions. Sum UX / Sum UY