Direct Fastening Technical Guide , Edition 24
NOTE : Straight-line interpolation between different steel deck thicknesses and steel deck strengths for the calculation of diaphragm shear strength values is permitted . For example , to calculate the allowable diaphragm shear strength , S nb
, for 65 ksi
Ω steel deck , the following formula would be used .
S n
S n
( 80 ksi ) = ( 65 ksi ) + ( 80 ksi - 65 ksi ) x )
Ω Ω
Where :
S n
( 92 ksi ) –
S n
Ω
Ω
92 – 65
( 65 ksi )
S n
Ω
S n
Ω
S n
Ω
( 65 ksi ) = Allowable diaphragm shear for 45 ksi steel deck . ( 92 ksi ) = Allowable diaphragm shear for 92 ksi steel deck . ( 80 ksi ) = Allowable diaphragm shear for 65 ksi steel deck .
Similarly , to calculate the allowable diaphragm shear , S ASD
, for 19 gauge ( 0.0418 in .) steel deck , the following formula would be used .
S n
S n
( 19 Ga .) = ( 20 Ga .) + ( 0 . 0418 in . - 0 . 0358 in .) x
Ω Ω
Where :
S n
( 18 ga .) – S n ( 20 ga .)
Ω
Ω
0.0474 in . – 0.0358 in .
S n
Ω
S n
Ω
S n
Ω
( 20 Ga .) = Allowable diaphragm shear for 20 gauge ( 0 . 0358 in .) steel deck . ( 18 Ga .) = Allowable diaphragm shear for 18 gauge ( 0 . 0474 in .) steel deck . ( 19 Ga .) = Allowable diaphragm shear for 19 gauge ( 0 . 0418 in .) steel deck .
Hilti is a leading manufacturer of direct fastening systems for steel and metal applications . As an associate member of the Steel Deck Institute ( SDI ), Hilti participates in and supports steel deck industry research at leading universities and test labs . Recent research projects with Hilti direct fastening systems have included inelastic seismic deck diaphragms and deep deck / cellular deck diaphragms .
Diaphragm data is calculated in accordance with AISI and SDI Diaphragm Design equations using specific Hilti fastener strength and stiffness values with data correlation adjustment factors in accordance with ICC-ES AC43 requirements .
Independent tests are the best guide to product performance and reliability , a philosophy to which Hilti and the SDI subscribe . The support for ongoing research programs is indicated by the number and scope of tests already performed and by the policy of sponsoring new tests when new products or applications are introduced . Hilti provides direct fastening system performance data , ICC-ES Evaluation Service Reports , design software , fire ratings and load test results for Hilti direct fastening systems used in steel deck applications .
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