AISCAISC 360-22
TablesK Additional requirements for HSS and box-section connections

Table K3.2A

PDF page 234 · AISC 360-22

Limits of Applicability of Table K3.2

Connection eccentricity:-0.55 ≤ e/H ≤ 0.25 for K-connections
Chord wall slenderness:B/t and H/t ≤ 35 for gapped K-connections and T-, Y-, and cross-connections
B/t ≤ 30 for overlapped K-connections
H/t ≤ 35 for overlapped K-connections
Branch wall slenderness:Bb/tb and Hb/tb ≤ 35 for tension branch
≤ 1.25 √E/Fyb for compression branch of gapped K-, T-, Y-, and cross-connections
≤ 35 for compression branch of gapped K-, T-, Y-, and cross-connections
≤ 1.1 √E/Fyb for compression branch of overlapped K-connections
Width ratio:Bb/B and Hb/B ≥ 0.25 for T-, Y-, cross-, and overlapped K-connections
Aspect ratio:0.5 ≤ Hb/Bb ≤ 2.0 and 0.5 ≤ H/B ≤ 2.0
Overlap:25% ≤ Ov ≤ 100% for overlapped K-connections
Branch width ratio:Bbi/Bbj ≥ 0.75 for overlapped K-connections, where subscript i refers to the overlapping branch and subscript j refers to the overlapped branch
Branch thickness ratio:tbi/tbj ≤ 1.0 for overlapped K-connections, where subscript i refers to the overlapping branch and subscript j refers to the overlapped branch
Material strength:Fy and Fyb ≤ 52 ksi (360 MPa)
Ductility:Fy/Fu and Fyb/Fub ≤ 0.8 Note: ASTM A500/A500M Grade C is acceptable.

Additional Limits for Gapped K-Connections

Width ratio:Bb / B and Hb / B ≥ 0.1 + γ / 50
βeff ≥ 0.35
Gap ratio:ξ = g/B ≥ 0.5(1-βeff)
Gap:g ≥ tb compression branch + tb tension branch
Branch size:smaller Bb ≥ 0.63(larger Bb), if both branches are square
TABLE K4.1 Available Strengths of Round HSS-to-HSS Moment Connections
Connection TypeConnection Available Flexural Strength
Branch(es) under in-plane bending T-, Y-, and cross-connections [Diagram of in-plane bending connection: Shows a round HSS chord with a branch HSS welded to it at an angle, illustrating dimensions M, Db, tb, θ, t, D]Limit state: chord plastification Mn-ip = 5.39Fyt20.5β (Db/sinθ) Qf (K4-1) φ = 0.90 (LRFD) Ω = 1.67 (ASD)
Limit state: shear yielding (punching), when Db < (D-2t) Mn-ip = 0.6FytDb2 ((1+3sinθ)/(4sin2θ)) (K4-2) φ = 0.95 (LRFD) Ω = 1.58 (ASD)
Branch(es) under out-of-plane bending T-, Y-, and cross-connections [Diagram of out-of-plane bending connection: Shows a round HSS chord with a branch HSS welded perpendicular to it, illustrating dimensions M, Db, tb, t, D]Limit state: chord plastification Mn-op = (Fyt2Db/sinθ) ((3.0)/(1-0.81β)) Qf (K4-3) φ = 0.90 (LRFD) Ω = 1.67 (ASD)
Limit state: shear yielding (punching), when Db < (D-2t) Mn-op = 0.6FytD2 ((3+sinθ)/(4sin2θ)) (K4-4) φ = 0.95 (LRFD) Ω = 1.58 (ASD)
For T-, Y-, and cross-connections, with branch(es) under combined axial load, in-plane bend-ing, and out-of-plane bending, or any combination of these load effects

Pr/Pc + (Mr-ip/Mc-ip)2 + Mr-op/Mc-op ≤ 1.0 (K4-5)

Pr = required axial strength in branch using LRFD or ASD load combinations, kips (N) Mr-ip = required in-plane flexural strength in branch using LRFD or ASD load combinations, kip-in. (N-mm) Mr-op = required out-of-plane flexural strength in branch using LRFD or ASD load combinations, kip-in. (N-mm) Pc = available axial strength obtained from Table K3.1, kips (N) Mc-ip = available strength for in-plane bending, kip-in. (N-mm) Mc-op = available strength for out-of-plane bending, kip-in. (N-mm)
TABLE K4.1A Limits of Applicability of Table K4.1
Chord wall slenderness:D/t ≤ 50 for T- and Y-connections D/t ≤ 40 for cross-connections
Branch wall slenderness:Db/tb ≤ 50
0.05E/Fyb ≤ Db/tb
Width ratio:0.2 < Db/D ≤ 1.0
Material strength:Fy and Fyb ≤ 52 ksi (360 MPa)
Ductility:Fy/Fu and Fyb/Fub ≤ 0.8 Note: ASTM A500/A500M Grade C is acceptable.

Table K3.2

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Additional Limits for Gapped K-Connections