Navigate to the window on the left side of the screen. Expand the Tables tab. Expand Analysis > Results > Structure Results . Double-click on Mass Summary by Story .
Understanding and validating the bridges the gap between raw CAD/BIM geometry and a mathematically sound structural model. By mastering this table, you guarantee that your lateral force-resisting systems are designed safely, economically, and exactly in accordance with modern building codes. If you want, I can:
The software automatically calculates mass based on structural geometry and material density. etabs mass summary by story
The Mass Summary by Story report will display, showing the mass properties for each story in your building model.
The story mass summary table is essential for checking vertical mass irregularity as defined by codes like ASCE 7, IS 1893, or BNBC. A vertical mass irregularity is often defined as a story's mass being significantly different (e.g., greater than 150% or less than 70%) of the mass of an adjacent story. A sudden jump or drop in the "Mass" column of the table serves as a clear and immediate warning sign of such an irregularity. Furthermore, the coordinates of the CM are used to calculate the accidental torsion demands in your seismic load cases. Navigate to the window on the left side of the screen
The portion of the story mass that is assigned directly to rigid or semi-rigid diaphragms.
In structural engineering, verifying a building's mass distribution is a critical quality control step. In ETABS, the table is the primary tool for validating structural weight, calculating seismic forces, and checking center of mass locations. Double-click on Mass Summary by Story
On a rainy Tuesday, Maya, a young structural engineer, opened ETABS to check the mass summary of a 12‑story apartment building she’d modeled. The model had been quiet for days, but tonight the mass summary promised answers.
Understanding Mass Summary by Story in ETABS In structural engineering, the Mass Summary by Story is a critical output in
The "Mass Summary by Story" table is completely dependent on how you've defined your structure's mass. It's crucial to distinguish between (a force from gravity) and mass (the resistance to acceleration, mass = weight / g). ETABS doesn't just use the weight of your structure; it builds the mass matrix used for dynamic analysis based on a user-defined Mass Source .
Total Story Mass=Self Weight+Assigned Dead Loads+(ψ×Live Loads)cap T o t a l space cap S t o r y space cap M a s s equals cap S e l f space cap W e i g h t plus cap A s s i g n e d space cap D e a d space cap L o a d s plus open paren psi cross cap L i v e space cap L o a d s close paren Troubleshooting Common Mass Discrepancies