Etabs Mass Summary By Story Better -

In your structural report, include:

To get the most out of the mass summary by story feature in ETABS, follow these best practices:

. A sudden spike or dip in mass between floors can signal a modeling error or a significant architectural change that will disproportionately attract seismic forces, helping to catch "soft story" or "weight irregularity" issues early. 2. Direct Verification of the "Mass Source" etabs mass summary by story better

The translational mass active in the X and Y directions. In most standard buildings, these values will be identical unless you have directional mass modifiers.

If you have ever run a seismic analysis in ETABS, you have undoubtedly stared at the table. It appears deceptively simple: a list of stories, masses in X, Y, Z, and a summation. Yet, for many engineers, this table is a source of quiet anxiety. In your structural report, include: To get the

Run the analysis ( F5 ) to ensure all mass matrices are formulated.

If you are encountering any specific during your mass source checks? Direct Verification of the "Mass Source" The translational

Let’s discuss your favorite verification techniques in the comments!

| Story | Mass DL | Mass 0.25LL | Total Mass | Seismic Weight (W) | Cumulative W | |-------|---------|-------------|------------|--------------------|---------------| | Roof | 850 | 50 | 900 | 8820 kN | 8820 kN | | PH | 300 | 10 | 310 | 3038 kN | 11858 kN | | 5 | 890 | 60 | 950 | 9310 kN | 21168 kN |

Instead of relying on ETABS’ automatic story grouping, define (e.g., Group-Roof-Beams , Group-Penthouse-Walls ). Then modify the Mass Summary by Group table. This gives you control to exclude non-structural masses that artificially inflate the story summary.