Etabs Mass Summary By Story Better

For the best results, ensure your is defined via Define > Mass Source . To avoid double-counting, don't check "Element Self Mass" if you are also including a Dead Load pattern with a 1.0 multiplier in your load list.

This article serves as a comprehensive guide to effectively using ETABS's mass summary features. We will explore its theoretical underpinnings, practical applications in seismic design, common pitfalls and their solutions, and advanced techniques for data extraction and analysis.

: Use "Additional Mass" to account for non-structural elements like partitions or cladding that aren't modeled as physical objects.

In ETABS, the is a critical diagnostic table used to verify the seismic weight and mass distribution of a structure. This data is essential for calculating the base shear during seismic analysis. Key Components of Story Mass etabs mass summary by story better

To get a better Mass Summary, you must stop using the default DEAD load case. You need to create a custom .

Total Story Mass=Slab Mass+Beams/Columns Mass+Wall/Cladding Mass+FinishesTotal Story Mass equals Slab Mass plus Beams/Columns Mass plus Wall/Cladding Mass plus Finishes

A junior engineer noticed the Mass Summary by Story showed only 1,200 kips of mass at the ground floor, while the architectural takeoff showed 1,800 kips. For the best results, ensure your is defined

: For seismic design, understanding the mass distribution is key. The mass of a structure directly influences its seismic response. A well-distributed mass can lead to a more stable structure under earthquake loads.

Navigate to the on the left side of the screen. Expand the Tables tab. Expand Analysis > Results > Structure Results . Double-click Mass Summary by Story to open the data grid. Key Columns Explained

Ensure your model is fully analyzed (press F5 ). This data is essential for calculating the base

A mechanical floor with heavy equipment should show a distinct spike in mass compared to a standard residential floor.

) under dead load cases to the total cumulative mass. These should align closely; a significant discrepancy often indicates unassigned masses.

ETABS only includes mass for elements physically modeled. If you have a heavy parapet, signboard, or mezzanine drawn as a line load—did you convert it to a mass? Model heavy non-structural components as point masses ( Assign > Shell/Area > Additional Mass ).