ETABS: Mass Summary by Story — Draft Article

Introduction

A concise guide on generating and interpreting mass summaries by story in ETABS, useful for structural engineers performing seismic and dynamic analysis.

💡 Pro Tip: Always compare the Total Mass in the summary table to the Base Reaction for a dead load case. They should be identical. If they aren't, your mass source is likely missing a specific load pattern.

The culprit? The Mass Summary by Story.

Identifying Modeling Errors: If the "Total Mass" does not match your base reactions, it often indicates elements meshed between stories or incorrect labeling of points.

Mass Moment of Inertia: The rotational mass about the Z-axis.

Scroll to Top
Real Time Web Analytics