SandorR
Student
- Dec 17, 2020
- 17
Hello all.
I am studying the requirements for Ordinary and Special Concentrically Braced Frames from AISC 341-22. Section F4c(g) states that in MTBF frame, at each tier level a notional load of 0.006 times the compression load contributed by the compression or tension brace intersecting the column at the tier level needs to be included, which is then used for second-order analysis. The word "or" confuses me slightly; does it mean we only need to use either the compression from tension brace or the compression brace? It would make more sense to me that we would include the vertical components of both the tension and compression brace. The article "Evaluation of Seismic Design Methods for Steel Multi-tiered Special Concentrically Braced Frames" by Cano and Imanpour states the rule as: "The notional load is equal to 0.006 times the vertical component of the compression brace that meets the column at the tier level." So they seem to be using the vertical component of only the compression brace.
So what would be correct way to interpret this rule? Why would we ignore the tension brace and only use the compression brace vertical load component?
I am studying the requirements for Ordinary and Special Concentrically Braced Frames from AISC 341-22. Section F4c(g) states that in MTBF frame, at each tier level a notional load of 0.006 times the compression load contributed by the compression or tension brace intersecting the column at the tier level needs to be included, which is then used for second-order analysis. The word "or" confuses me slightly; does it mean we only need to use either the compression from tension brace or the compression brace? It would make more sense to me that we would include the vertical components of both the tension and compression brace. The article "Evaluation of Seismic Design Methods for Steel Multi-tiered Special Concentrically Braced Frames" by Cano and Imanpour states the rule as: "The notional load is equal to 0.006 times the vertical component of the compression brace that meets the column at the tier level." So they seem to be using the vertical component of only the compression brace.
So what would be correct way to interpret this rule? Why would we ignore the tension brace and only use the compression brace vertical load component?
