Etabs Mass Summary By Story Better Jun 2026

Before any mass summary can be understood, the engineer must define exactly what constitutes the building's mass. This is done in the menu. Getting this definition right is the single most critical step. A major international study analyzing a 17-story building found that the choice of mass source definition directly impacts key results: the 'From self and specified mass' option produced the lowest values for time period, base shear, and story drift; the 'From loads' definition was the most accurate ; other options produced results that were overly conservative.

The rotational mass about the Z-axis.

ASCE 7 allows reduced live loads for seismic mass (e.g., 25% of floor live load in storage areas). The default summary does not apply these reductions automatically. You need a better mass source. etabs mass summary by story better

Verify that rigid and semi-rigid diaphragms are correctly distributing loads. Before any mass summary can be understood, the

This yields raw data that you can filter and plot. A major international study analyzing a 17-story building