Aluminum RT Member Capacity
description
Transcript of Aluminum RT Member Capacity
-
PROJECT : PAGE : CLIENT : DESIGN BY :
JOB NO. : DATE : REVIEW BY :
INPUT DATA & DESIGN SUMMARYMEMBER SIZE RT 1 3/4 4 1/8 d b A Ix Iy E Wt (lbs/ft)
4 1.75 1.38 2.7 0.7 10100 1.62F tu = 30 ksiF ty = 25 ksiF cy = 25 ksi
AXIAL COMPRESSION FORCE P = 3 kips, ASDSTRONG GEOMETRIC AXIS EFFECTIVE LENGTH kL x = 6.4 ftWEAK GEOMETRIC AXIS EFFECTIVE LENGTH kL y = 3.2 ft
M rx = 1.2 ft-kips, ASDSTRONG GEOMETRIC AXIS BENDING UNBRACED LENGTH L bx = 2 ftSTRONG DIRECTION SHEAR LOAD, ASD V strong = 30 kips
M ry = 0.35 ft-kips, ASDWEAK DIRECTION SHEAR LOAD, ASD V weak = 20 kips
THE DESIGN IS ADEQUATE.
ANALYSISCHECK COMPRESSION STRESS IN AXIAL FORCE
10.13 ksi, (compression in column, AA ADM-IA 3.4.7)
Where r x = 1.410 in, (Page VI-34 to VI-37)
r y = 0.730 in, (Page VI-34 to VI-37)
kL / r = Max( kL x / r x , kL y / r y ) = 54.47E = 10100 ksi, (Table 3.3-1)B c = F cy [1 + (F cy / 2250)
0.5 ] = 27.64 , (Table 3.3-4)
D c = (B c / 10) (B c / E)0.5 = 0.14 , (Table 3.3-4)
C c = 0.41 (B c / D c ) = 78.38 , (Table 3.3-4)
n u = 1.95 , (Table 3.4-1)
n y = 1.65 , (Table 3.4-1)
S 1 = (B c - n u F cy / n y ) / D c = 0.00 , (Eq. 3.4.7-4)
S 2 = C c = 78.38 , (Eq. 3.4.7-5)
11.80 ksi, (compression in web, AA ADM-IA 3.4.9)
Where b / t = 30.000 , (Figure 3.4.9-1)k 1 = 0.35 , (Table 3.3-4)k 2 = 2.27 , (Table 3.3-4)B p = F cy [1 + F cy
(1/3) / 11.4] = 31.41 , (Table 3.3-4)
STRONG GEOMETRIC AXIS BENDING MOMENT
WEAK GEOMETRIC AXIS BENDING MOMENT
Aluminum RT Member Capacity Based on Aluminum Design Manual 2005 (AA ADM-IA)
TENSILE YIELD STRESS (T5, T6, T7, T8, or T9)
COMPRESSIVE YIELD STRESS (T5 to T9)
TENSILE ULTIMATE STRESS (T5 to T9, Tab 3.3-1)
1
1 21
222
,
,
,
cy
y
cc
au
u
kLF for SrnkLDB kLr for S SF rn
E kLfor SrkLn r
1
2 1 2
22
,
1.6
,
,1.6
cy
y
pp
au
p
u
bF for StnbD
B t bF for S StnEk B bfor Sb tn t
pc12Highlight
pc12Highlight
pc12Rectangle
-
(cont'd)D p = (B p / 10) (B p / E)
0.5 = 0.18 , (Table 3.3-4)
S 1 = (B p - n u F cy / n y ) / (1.6 D p ) = 6.66 , (Eq. 3.4.9-4)
S 2 = k 1 B p / (1.6 D p ) = 39.22 , (Eq. 3.4.9-5)
f a = P / A = 2.17 ksi < F a = Min (F a 1 , F a 2 ) = 10.13 ksi[Satisfactory]
CHECK TENSION STRESS IN BENDING MOMENTSF = 15.15 ksi, (tension in bending, AA ADM-IA 3.4.2 & 3.4.4)
Where k t = 1.00 , (Table 3.4-2)
f = Max (M rx / S x , M ry / S y ) = 10.51 ksi < F = 15.15 ksi[Satisfactory]
Where S x = 1.37 in, (Page VI-34 to VI-37)
S y = 0.84 in, (Page VI-34 to VI-37)
CHECK COMPRESSION STRESS IN STRONG GEOMETRIC AXIS, x - x, BENDING MOMENT
15.15 ksi, (compression in beam, AA ADM-IA 3.4.14)
Where S 1 = (B c - F cy )2 / (1.6 D c )
2 = 129.82 , (Eq. 3.4.14-4)
S 2 = (C c /1.6)2 = 2399.9 , (Eq. 3.4.14-5)
J = 1.8 , (Page VI-34 to VI-37)S c = S x = 1.37 in, (Page VI-34 to VI-37)
C b = 1.00 , (AA ADM-IA 4.9.4)
L b S c / [C b (I y J)0.5 / 2] = 57.29
15.15 ksi, (compression in flanges, AA ADM-IA 3.4.16)
Where b / t = 12.000 , (Figure 3.4.8-1)k 1 = 0.5 , (Table 3.3-4)k 2 = 2.04 , (Table 3.3-4)
S 1 = (B p - F cy ) / (1.6 D p ) = 22.88 , (Eq. 3.4.16-4)
S 2 = k 1 B p / (1.6 D p ) = 56.04 , (Eq. 3.4.16-5)
19.72 ksi, (compression in web, AA ADM-IA 3.4.18)
Where h / t = 30.000 , (Figure 3.4.18-1)c c = c o = 2 in
Min (F ty /n y , F tu / k t n u , 1.3F ty /n y , 1.42F tu / k t n u ) =
1
1 21
22
,/ 2
1 1.6 ,/ 2 / 2
,/ 2
2.56/ 2
cy b c
y yb
b bc cc c
y y yb bbx
b c
ybb cy
yb
F SLfor SJn C I
S SL Lfor S SB DJ Jn C CI IF
E SLfor SJC ISLn
JC I
1
2 1 2
22
,
1.6
,
,1.6
cy
y
pp
bxy
p
y
bF for StnbD
B t bforF S Stn
Ek B bfor Sb tn t
1
3 1 2
22
1.3 ,
,
,
cy
y
brbr
bxy
br
y
F hfor StnhmDB ht forF S S
tn
E hk B for Smh tn t
-
(cont'd)m = 0.65 , (Table 3.3-4)B br = 1.3 F cy [1 + F cy
(1/3) / 7] = 46.08 , (Table 3.3-4)
D br = (B br / 20) (6 B br / E)(1/3) = 0.69 , (Table 3.3-4)
S 1 = (B br - 1.3 F cy ) / (m D br ) = 0.45 , (Eq. 3.4.18-4)
S 2 = k 1 B br / (m D br ) = 51.05 , (Eq. 3.4.18-5)
f bx = M rx / S x = 10.51 ksi < F bx = Min (F bx 1 , F bx 2 , F bx 3 ) = 15.15 ksi[Satisfactory]
CHECK COMPRESSION STRESS IN WEAK GEOMETRIC AXIS, y - y, BENDING MOMENT
13.94 ksi, (compression in flanges, AA ADM-IA 3.4.16)
Where b / t = 30.000 , (Figure 3.4.8-1)
f by = M ry / S y = 5.02 ksi < F by = 13.94 ksi[Satisfactory]
CHECK COMBINED COMPRESSION AND BENDING (AA ADM-IA 4.1.1)
1.27 < 1.33 , (1.33 if IBC/CBC 1605.3.2 apply)[Satisfactory]
Where C mx = 0.85
C my = 0.85
F ex = 2 E / n u (kL x /r x ) 2 = 17.23 ksiF ey = 2 E / n u (kL y /r y ) 2 = 18.47 ksi
CHECK SHEAR STRESS (AA ADM-IA 3.4.20)
8.75 ksi, (for strong shear)8.75 ksi, (for weak shear)
Where h / t = 30.000 , (for strong shear, Figure 3.4.18-1)h / t = 12.000 , (for weak shear, Figure 3.4.18-1)B s = (F cy / 3
0.5 ) [1 + (F cy / 30.5 ) (1/3) / 9.3] = 18.21 , (Table 3.3-4)
D s = (B s / 10) (B s / E)0.5 = 0.08 , (Table 3.3-4)
C s = 0.41 B s / D s = 96.55 , (Table 3.3-4)
S 1 = (B s - F cy / 30.5 ) / (1.25 D s ) = 39.09 , (Eq. 3.4.20-4)
S 2 = C s / 1.25 = 77.24 , (Eq. 3.4.20-5)
f s = V strong / A w = 3.75 ksi < F s = 8.75 ksi, (for strong shear)f s = V weak / A w = 5.71 ksi < F s = 8.75 ksi, (for weak shear)
[Satisfactory]
1 / 1 /my bymxa bx
a bx ex by eya a
bya bx
a bx by
fCf fCf fF F F F F
Maxff f
F F F
1
1 2
222
/ 3,
1.25
,
,1.25
ty
y
ss
sy
y
hF for StnhDB ht for S SF tn
E hfor Sthn t
1
1 2
22
,
1.6
,
,1.6
cy
y
pp
bxy
p
y
bF for StnbD
B t bforF S Stn
Ek B bfor Sb tn t