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Posts tagged: seismic-wind
4 posts tagged with “seismic-wind”.
Zero Mass Participation in ETABS: Why Your Modal Results Are Wrong and Where to Look
The UX and UY columns read zero, sometimes with a period that makes no sense. The model ran, nothing crashed, and the dynamics are completely wrong. It's rarely mysterious: the table itself tells you which of four causes you've got.
5 min read
Diaphragm Assignment in ETABS: The Mistake That Quietly Drops Your Seismic Mass
Miss a diaphragm on a floor, or assign it to the wrong thing, and nothing complains. The model runs, the seismic loads generate, the results look complete. Part of the building's mass has quietly stopped participating, and the accidental torsion on that floor has disappeared.
5 min read
Importance Level: The One Decision That Quietly Sets Your Entire Load Regime
It's a single classification you make near the start, often almost administratively. It silently scales every wind and seismic load the structure is designed for, and the error is baked in before you draw a member.
6 min read
Coupling Beams: The Most Abused Element in Tall-Building Design
The coupling beam is small, awkward, and sits in the way of the architecture. It's also the element that decides how your coupled-wall system actually behaves, and it gets modelled wrong more often than almost anything else in a tall building.
6 min read