Product Technical Guides : US-EN Modular Systems Product Technical Guide | Page 27

Modular Support Systems Technical Guide , Edition 1
3.0 MODULAR SUPPORT SYSTEM 3.1.1 CROSS-SECTION PROPERTIES OF MT PROFILES
Table 7 - Cross-Section Properties of MT Channel Profiles 1 , 3 , 4 , 5
Description
Symbol Units
MT-20 MT-20 OC
MT-30 S MT-30 MT-30 S OC MT-30 OC
MT-50 S MT-50 MT-50 S OC MT-50 OC
MT-60 S MT-60 MT-60 S OC MT-60 OC
Profile of cross-section - -
Design thickness
t
in
( mm )
0.069
( 1.75 )
0.079
( 2 )
0.108
( 2.75 )
0.108
( 2.75 )
Width
-
in
( mm )
1.10
( 28 )
1.67
( 42.5 )
1.67
( 42.5 )
1.67
( 42.5 )
Depth
-
in
( mm )
1.67
( 42.5 )
0.91
( 23 )
1.67
( 42.5 )
2.83
( 72 )
Weight
w
lbs / ft
( kg / m )
0.84
( 1.25 )
1.1
( 1.64 )
1.97
( 2.93 )
2.83
( 4.21 )
Minimum specified yield strength
F y
ksi
( MPa )
40.6
( 280 )
40.6
( 280 )
40.6
( 280 )
40.6
( 280 )
Modulus of elasticity
E
ksi
( MPa )
29,500
( 203,400 )
29,500
( 203,400 )
29,500
( 203,400 )
29,500
( 203,400 )
Gross Section Properties 2
Gross cross-sectional area
A g
in 2
( mm 2 )
0.291
( 187.59 )
0.322
( 207.95 )
0.583
( 376.02 )
0.834
( 538.27 )
Moment of inertia of the gross section about x-axis
I x
in 4
( mm 4 )
0.0489
( 20,349 )
0.0351
( 14,621 )
0.2033
( 84,619 )
0.7904
( 329,006 )
Moment of inertia of the gross section about y-axis
I y
in 4
( mm 4 )
0.1272
( 52,943 )
0.1274
( 53,018 )
0.2611
( 108,670 )
0.4153
( 172,864 )
Gross section-modulus about x-axis
S x
in 3
( mm 3 )
0.0742
( 1,216 )
0.067
( 1,098 )
0.2165
( 3,548 )
0.5146
( 8,432 )
Gross section-modulus about y-axis
S y
in 3
( mm 3 )
0.152
( 2,491 )
0.1523
( 2,495 )
0.3121
( 5,114 )
0.4964
( 8,135 )
Radius of gyration of the gross section about x-axis
r x
in
( mm )
0.41
( 10.42 )
0.33
( 8.39 )
0.591
( 15 )
0.973
( 24.72 )
Radius of gyration of the gross section about y-axis
r y
in
( mm )
0.661
( 16.8 )
0.629
( 15.97 )
0.669
( 17 )
0.706
( 17.92 )
Effective Section Properties
Effective moment of inertia about x-axis
I x-eff
in 4
( mm 4 )
0.0443
( 18,439 )
0.0327
( 13,594 )
0.2005
( 83,452 )
0.7802
( 324,725 )
Effective moment of inertia about y-axis
I y-eff
in 4
( mm 4 )
0.0901
( 37,509 )
0.1264
( 52,608 )
0.2611
( 108,664 )
0.4153
( 172,858 )
Effective section modulus about x-axis at stress = F y
S x-eff
in 3
( mm 3 )
0.0673
( 1,102 )
0.0623
( 1,021 )
0.2135
( 3,499 )
0.5079
( 8,323 )
Effective section modulus about y-axis at stress = F y
S y-eff
in 3
( mm 3 )
0.1077
( 1,765 )
0.1511
( 2,476 )
0.3121
( 5,114 )
0.4964
( 8,135 )
Allowable bending moment based on local buckling about x-axis ( Ω b = 1.67 )
M a-x
k-in
( kN m )
1.845
( 0.208 )
1.92
( 0.216 )
6.8
( 0.768 )
15.53
( 1.755 )
Allowable bending moment based on local buckling about y-axis ( Ω b = 1.67 )
M a-y
k-in
( kN m )
2.88
( 0.325 )
4.21
( 0.476 )
8.46
( 0.956 )
12.8
( 1.446 )
Allowable bending moment for distortional buckling about x-axis based on Kϕ = 0 ( Ω b = 1.67 )
M ad-x
k-in
( kN m )
1.685
( 0.19 )
1.77
( 0.199 )
6.03
( 0.682 )
12.41
( 1.402 )
Allowable bending moment for distortional buckling about y-axis based on Kϕ = 0 ( Ω b = 1.67 )
M ad-y
k-in
( kN m )
2.501
( 0.283 )
3.79
( 0.428 )
8.46
( 0.956 )
11.88
( 1.342 )
Allowable shear about x-axis ( Ω v = 1.6 )
V a-x
lbs
( N )
1,466
( 6,516 )
1,629
( 7,240 )
2,103
( 9,348 )
2,103
( 9,348 )
Allowable shear about y-axis ( Ω v = 1.6 )
V a-y
lbs
( N )
1,735
( 7,712 )
1,416
( 6,295 )
4,205
( 18,691 )
8,036
( 35,720 )
Torsional Section Properties 2
St . Venant Torsional Constant
J
in 4
( mm 4 )
0.0005
( 191.50 )
0.0007
( 277.26 )
0.0023
( 947.89 )
0.0033
( 1,356.90 )
Torsional Warping Constant
C w
in 6
( mm 6 )
0.0368
( 9,881,442 )
0.0323
( 8,685,395 )
0.1593
( 42,771,610 )
0.5991
( 160,884,400 )
Distance from the centroid to the shear center along the principal x-axis
X 0
in
( mm )
0
0
0
0
Distance from the centroid to the shear center along the principal y-axis
Y 0
in
( mm )
0.988
( 25.1 )
0.868
( 22.05 )
1.579
( 40.11 )
2.740
( 69.59 )
Distance from shear center to centroid to mid-plane of web
m
in
( mm )
0.60
( 15.1 )
0.45
( 11.4 )
0.90
( 22.9 )
1.50
( 38.0 )
Net polar radius of gyration about the shear center
r 0
in
( mm )
1.258
( 31.95 )
1.122
( 28.49 )
1.814
( 46.07 )
2.992
( 76.00 )
Coefficient for determining critical elastic lateral-torsional buckling stress β - 0.4 0.4 0.2 0.2
1 . Tabulated values are in accordance with ICC-ES ESR-5019 and AISI-S100-16 , the North American Specification for the Design of Cold-Formed Steel Structural Members . 2 . Tabulated gross properties , including torsional properties , are based on the full unreduced cross section of the profiles , away from the punched holes and slots . 3 . For deflection calculations , use the effective moment of inertia . 4 . Allowable moment is the lesser of M a and M ad
. 5 . C . G . is the center of gravity of the profile cross-section .
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