This message is created by specifying the element name and floor on which it is located at the beginning of the report.
SB001 BASE STORY Lateral bracing check is not satisfied.
In steel structural system beams of special moment frames and intermediate moment frames, in accordance with AISC 341-16 and TBDY Chapter 9 codes, both flanges of members should be laterally braced, or the beam cross-section should be braced with point torsional bracing.
As stated in AISC 341-16 D1 2b;
The maximum spacing of bracing for highly ductile beams should satisfy the following requirements.
The maximum spacing of bracing for moderately ductile beams should satisfy the following requirements.
The lateral bracing distance can be reduced by connecting roof braces (horizontal braces) and stability elements to the steel beam whose name and floor are given.
The lateral bracing distance can be reduced by defining secondary steel beams and stability elements to the steel beam whose name and floor are given.
Lb : Length between points that are either braced against lateral displacement of compression flange or braced against the twist of the cross-section, in. (mm)
E : Modulus of elasticity of steel = 29,000 ksi (200 000 MPa)
Fy : Specified minimum yield stress, ksi (MPa).
Ry : Ratio of the expected yield stress to the specified minimum yield stress, Fy
ry : Radius of gyration about y-axis, in. (mm)