The required axial and flexural strength for connection equilibrium is determined as follows: LRFD
ASD
∑F
= 9.60 kips + 48.0 kips + 288 kips − Puconn
Pu conn
=0 = 346 kips
v
∑F
= 8.00 kips + 32.0 kips + 192 kips − Paconn
Pa conn
=0 = 232 kips
v
LRFD
∑M
A
∑M
= 360 kip-ft − 72.0 kip-ft − 2 M u conn
( 20.0 in. / 2) 48.0 kips − 9.60 kips ( ) 12 in./ft
+
M u conn
ASD = 240 kip-ft − 60.0 kip-ft − 2 Ma conn
A
+
=0 = 160 kip-ft
( 20.0 in. 2)
(32.0 kips − 8.00 kips)
12 in./ft
=0 = 100 kip-ft
M a conn
Use a plate width of 14.0 in. to permit fillet welding to the HSS. To begin, use a plate thickness equal to the beam flange thickness (tp tf) to determine the approximate maximum force in the plate, Ru and Ra. LRFD
d t R f
u
ASD
d t R
M u right
f
16.4 in. 0.715 in. R
u
360 kip-ft 12 in./ft
Ru 252 kips
a
M a right
16.4 in. 0.715 in. R
a
240 kip-ft 12 in./ft
Ra 168 kips
Tensile yielding of through-plate Using AISC Specification Section J4.1(a), determine the through-plate thickness, tp, based on tensile yielding. The force in the plate, Ru and Ra, can then be determined. LRFD
ASD
0.90 Ru Ag Fy
1.67 Ra Ag Fy
252 kips 0.90 36 ksi
168 kips 36 ksi 1.67
7.79 in.2
7.78 in.2 7.78 in.2 14.0 in. 0.556 in.
7.79 in.2 14.0 in.
tp
tp
Use t p s in.
0.556 in. Use t p s in.
(d + t ) R
(d + t ) R
p
u
= M u right
(16.4 in. + s in.) R
u
Ru = 254 kips
p
= 360 kip-ft (12 in./ft
)
a
= M a right
(16.4 in. + s in.) R
a
= 240 kip-ft (12 in./ft
)
Ra = 169 kips
AISC DESIGN GUIDE 24 / HOLLOW STRUCTURAL SECTION CONNECTIONS / 39