# F2.3 Analysis

This control’s not checked by programme.

**Symbols**

* A_{g}* = Gross area of member, in.

^{2}(mm

^{2})

**F**Specified minimum yield stress

_{y}=**R**Ratio of the expected yield stress to the specified minimum yield stress, Fy

_{y}=**F**Critical stress calculated from Specification Chapter E using expected yield stress, ksi (MPa)

_{cre}=**P**Compressive strength

_{1}=**P**Compressive strength for

_{2}=**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, E_{cl}, is taken as the larger force determined from the following analyses:

(a) An analysis in which all braces are assumed to resist forces corresponding to their expected strength in compression or in tension

(b) 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 R_{y}F_{y}A_{g}, where A_{g} is the gross area, in.^{2} (mm^{2}). The expected brace strength in compression is permitted to be taken as the lesser of R_{y}F_{y}A_{g} and (1/0.877)F_{cre}A_{g}, where F_{cre} is determined from Specification Chapter E using the equations for F_{cr}, except that the expected yield stress, R_{y}F_{y}, is used in lieu of F_{y}. The brace length used for the determination of F_{cre} shall not exceed the distance from brace end to brace end.

The expected post-buckling brace strength shall be taken as a maximum of * 0.3 times* the expected brace strength in compression.

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