Section G2.1/Shear Strength of Webs
AISC 360-22 Section G2 covers nominal shear strength of I-shaped member webs including web buckling and compact/slender classification.
The nominal shear strength of an I-shaped member web is Vn = 0.6 Fy Aw Cv1, where Aw is the web area (d times tw) and Cv1 is the web shear buckling coefficient. For compact webs (h/tw not exceeding 2.24 times the square root of E/Fy), Cv1 = 1.0 and phi = 1.0. For slender webs, Cv1 is reduced based on the h/tw ratio and the web may buckle before reaching full shear yield. Most standard W-shapes have compact webs for shear in A992 steel.
Why this section exists
Beam webs resist the vertical shear from applied loads. A thin web under high shear stress can buckle diagonally (shear buckling), reducing its capacity below the full shear yield value. The web slenderness ratio (h/tw) determines whether the web is compact (reaches full yield before buckling) or slender (buckles before yield). Most rolled W-shapes are compact for shear, but plate girders and built-up sections often have slender webs that require a reduced shear capacity.
What plan reviewers look for
Plan reviewers check beam shear calculations, especially at supports and concentrated load points where shear is highest. They verify that the web slenderness is classified correctly. For plate girders and built-up sections, they check for intermediate stiffeners that may be required to develop post-buckling strength through tension field action.
Common violations
Related AISC 360 requirements
Chapter F covers flexural strength (which is checked alongside shear). Section G3 covers shear strength with tension field action for stiffened webs. Section J10 covers web local yielding, crippling, and sidesway buckling at concentrated forces (bearing points).