PROFIS Design Guide - AC 318-19 July 2022 | Page 328

2.5 Steel Failure with Lever Arm

Calculations

1 ‒

N _ua

ϕN _sa

Calculations ETAG 001 Annex C Provision Comments for PROFIS Engineering

1 ‒ ^N ua

ϕN _sa

5.2.3.2 Steel failure b ) Shear load with lever arm

ETAG 001 reduction for tensile force acting on the anchor ( 1 ‒ N _Sd

/ N _{Rd , s}

) resultant flexural resistance of anchor

M _{Rk , s}

= M ^{0 ( 1 ‒ N / N} ) [ Nm ] ( 5 . 5a )

Rk , s Sd Rd , s

The characteristic resistance of an anchor , V _{Rk , s} , is given by Equation ( 5.5 ).

V _{Rk , s}

= ^α M ^M Rk , s [ N ] ( 5.5 ) l where α _M

= see 4.2.2.4 l = lever arm according to Equation ( 4.2 )

M _{Rk , s}

= M ^{0 ( 1 - N / N} ) [ Nm ] ( 5 . 5a )

Rk , s Sd Rd , s

N _{Rd , s}

= N _{Rk , s} / Y _Ms

N _{Rk , s}

, Y _Ms to be taken from the relevant ETA M ⁰ = characteristic bending resistance of an individual anchor

Rk , s

The value of M ⁰ for anchors according to current experience is obtained from Equation ( 5 . 5b ).

Rk , s

M ⁰ Rk , s ^{= 1 . 2 W} el ^ƒ uk

[ Nm ] ( 5 . 5b )

The figures below illustrate ETAG 001 design assumptions with respect to bolt bending . PROFIS Engineering nomenclature for ACI 318 calculations is used in the illustrations .

Shear and tension load act on an anchorage with standoff .

PROFIS Engineering uses the provisions given in the European Technical Approval Guideline ( ETAG ) titled ETAG 001 Metal Anchors for Use in Concrete Annex C : Design Methods for Anchorages to consider bolt bending as a possible shear failure mode .

The ETAG 001 parameter M ⁰ corresponds to a calculated internal

Rk , s

“ characteristic bending resistance ” for the anchor element . If both tension and shear loads act on the anchor , ETAG 001 provisions require a reduction factor ( 1 – N _sd

/ N _{Rd , s}

) to be applied to M ⁰ , and the resulting parameter is designated

Rk , s

“ M _{Rk , s} ” per Equation ( 5.5a ). The parameters “ N _sd

” and “ N _{Rd , s}

” in Equation ( 5.5a ) correspond to the “ design steel tension force ” and the “ design resistance steel force ”, respectively .

PROFIS Engineering designates the parameters in Equation ( 5.5a ) as follows : “ M _{Rk , s}

” is designated “ M _s

” “ M ⁰ Rk , s ^{” is designated “ M0} s ^” “ N _sd

” is designated “ N _ua ”

“ N _{Rd , s} ” is designated “ фN _sa

”

PROFIS Engineering defines the parameters for the Equation ( 5.5a ) tension modification factor as follows :

N _ua

= highest factored tension load acting on an individual anchor

фN _sa

= design steel strength in tension for a single anchor .

Reference the Variables section in Part 4.2 of the PROFIS Engineering report for more information on the parameters N _ua and фN _sa when used in ETAG 001

Equation ( 5.5a ). The values for N _ua and фN _sa are taken from Part 3.1 ( steel strength in tension calculations ) of the PROFIS Engineering report .

PROFIS Engineering calculations