Product Technical Guides : US-EN Direct Fastening - Volume 1 Edition 22 | Page 164

C = ( w )( 2α 3
AISI S310 steel deck diaphragm stiffness and flexibility factor design equations :
Et

G ' = ( Et 2 ( 1 + μ ) s K =

+ γ c
D n
+ C d

) ( ) 3 . 78 + 0 . 9D + C , kips / in . Eq . D5 . 1 . 1-1

F = 1 , 000
G '
E = modulus of elasticity of steel = 29,500 ksi
D n
= D L
Et 2L

C = ( w )( 2α 3

+ n p α 4
+ 2n s s r

) s s

S f
Eq . D5.1.1-1
Eq . D5 . 1 . 1-2
Reference Tables 7 and 9 for description and values of other variables for common conditions .
Table 7 – Diaphragm strength ( S ) and stiffness factor ( G ') equation variable values 1
Deck type
Fastener pattern
α 1 or α 3
– end distribution factor
α 2 or α 4 – purlin distribution factor
Σx ee
2 or
Σx e2
, in . 2
Σx pe
2 or
Σx xp2
, in . 2
A
N , ft
D-Warping constant , in .
22 GA 20 GA 18 GA 16 GA
36 / 11 3.667 3.667 1,944 1,944 2 3.000 1,235 924 606 428
1-1 / 2 " Wide Rib B- or BI- Deck
36 / 9
3.000
3.000
1,656
1,656
2
2.333
1,235
924
606
428
36 / 7
2.000
2.000
1,008
1,008
1
2.000
1,235
924
606
428
36 / 5
1.667
1.667
936
936
1
1.333
7,288
5,452
3,578
2,525
36 / 4
1.333
1.333
720
720
1
1.000
10,315
7,715
5,064
3,574
36 / 3 1.000 1.000 648 648 1 0.667 21,217 15,871 10,417 7,315
1 Reference ICC-ES ESR-2776 for Verco PLB deck and VSC2 sidelap connectors
164