Etabs Mass Summary By Story -

If you’ve ever run a seismic analysis in ETABS, you’ve probably scrolled past the Mass Summary by Story table. It looks harmless enough—just a few columns of numbers under the Display > Show Tables > Analysis > Results > Structure Output menu.

Self-weight assignment.

If you model a semi-rigid diaphragm, ETABS distributes mass to every joint in the slab. If you model a rigid diaphragm, ETABS lumps the entire floor’s mass at the Center of Mass (CM). etabs mass summary by story

In fact, most convergence errors, unexpected mode shapes, and even incorrect base shears can be traced back to a single misunderstood line in this table. If you’ve ever run a seismic analysis in

But here is a hard truth:

The "Where is my Mass?" Mystery Here is the most common panic moment for engineers: "I assigned a 10-inch slab, beams, columns, and walls... so why does the Mass Summary show almost nothing on the roof?" If you model a semi-rigid diaphragm, ETABS distributes