Analysis for SCBF per AISC 341-16 with ideCAD
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Symbols
Ag = Gross area of member, in.2 (mm2)
Fy = Specified minimum yield stress
Ry = Ratio of the expected yield stress to the specified minimum yield stress, Fy
Fcre = Critical stress calculated from Specification Chapter E using expected yield stress, ksi (MPa)
P1 = Compressive strength
P2 = Compressive strength for post-buckling
T = Tensile strength
The required strength of elements and connections in SCBF are determined using the capacity-limited seismic load effect. The capacity-limited horizontal seismic load effect, Ecl, is taken as the larger force determined from the following analyses:
An analysis in which all braces are assumed to resist forces corresponding to their expected strength in compression or in tension
An analysis in which all braces in tension are assumed to resist forces corresponding to their expected strength, and all braces in compression are assumed to resist their expected post-buckling strength.
The expected brace strength in tension is RyFyAg. The expected brace strength in compression is permitted to be taken as the lesser of RyFyAg and (1/0.877)FcreAg, where Fcre is determined from Specification Chapter E using the equations for Fcr, except that the expected yield stress, RyFy, is used in lieu of Fy. The brace length used to determine Fcre shall not exceed the distance from the brace end to the brace end.
The expected post-buckling brace strength shall be taken as a maximum of 0.3 times the expected brace strength in compression.
