Beam Stability

How does ideCAD define T-beam effective width according to ACI 318-19?

Notation

b_f = effective flange width, in.
b_w = web width or diameter of circular section, in.
h = overall thickness, height, or depth of member, in.
l_n = length of clear span measured face-to-face of supports, in.
s_w = clear distance between adjacent webs, in.

In nonprestressed T-Beam monolithic concrete construction, the effective flange width, b_f, equals the beam width b_w, plus an effective overhanging flange width in accordance with ACI Table 6.3.2.1.

h is the slab thickness and s_w is the clear distance to the adjacent web.

According to ACI 6.3.2.2, isolated nonprestressed T-beams as used to provide additional compression area, should have a flange thickness greater than or equal to 0.5b_w and an effective flange width less than or equal to 4b_w.