Etabs Mass Summary By Story Portable -

Mass summary matches hand calculation. Modal analysis can proceed.

Verify that the total seismic mass matches the design calculation.

You can use this as a template or a direct submission for a course or technical report. etabs mass summary by story

If the weight for a story is zero, check that the diaphragms are properly assigned and the materials are defined with a non-zero density. Conclusion

The running total of mass from the top of the structure down to the current story. Mass summary matches hand calculation

You defined mass source from load patterns but forgot to assign any load pattern to the roof diaphragm. Or, you used a rigid diaphragm but the beams are not connected to the diaphragm constraint.

The top story often has a lower total mass compared to lower stories because it lacks the weight of structural columns and walls from the floor above. You can use this as a template or

Pick a typical intermediate floor in your building and estimate its weight manually: