Ayuda

[chuito3000]

Buenas tardes a toda esta comunidad, soy relativamente nuevo en el uso de los programas CSI (estudiandolos todavia), tengo un problemita en el ETABS, ya que estoy modelando una estructura con perfiles de acero H e I, pero al momento que hago el diseño de una vigas compuestas de 2 secciones, algunas de ellas me aparecen rojo aun cuando estan trabajando a un 13% de su capacidad y cuando veo los detalles de la viga me indica esto:

Lb/ry > 0.086*E/fy (ANSI/AISC 341-10 E3.4b, D1.2b)

Si alguien me pudiera indicar que significa esa expresion por favor, estaría agradecido enormemente!!!

[HH500]

D1. MEMBER REQUIREMENTS
Members of moment frames, braced frames and shear walls in the seismic force resisting system (SFRS) shall comply with the Specification and this section. Certain members of the SFRS that are expected to undergo inelastic deformation under the
design earthquake are designated in these provisions as moderately ductile members or highly ductile members.

2b. Highly Ductile Members
In addition to the requirements of Sections D1.2a(a)(1) and (2), and D1.2a(b)(1) and (2), the bracing of highly ductile beam members shall have a maximum spacing of Lb = 0.086ryE/Fy. For concrete-encased composite beams, the material properties of
the steel section shall be used and the calculation for ry in the plane of buckling shall be based on the elastic transformed section.

E3. SPECIAL MOMENT FRAMES (SMF)
4b. Stability Bracing of Beams
Beams shall be braced to satisfy the requirements for highly ductile members in Section D1.2b.
In addition, unless otherwise indicated by testing, beam braces shall be placed near concentrated forces, changes in cross section, and other locations where analysis indicates that a plastic hinge will form during inelastic deformations of the SMF. The placement of lateral bracing shall be consistent with that documented for a prequalified connection designated in ANSI/AISC 358, or as otherwise determined in a connection prequalification in accordance with Section K1, or in a program of qualification testing in accordance with Section K2.
The required strength of stability bracing provided adjacent to plastic hinges shall be as required by Section D1.2c


https://www.aisc.org/WorkArea/showcontent.aspx?id=29248