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RE: Tensile capacity of threaded rods

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In the PCA Strength Design of Anchorage to Concrete 
publication on page 7 it states that "the effective 
cross-sectional area of the fastener (Ase) is the net 
tensile stress area for threaded fasteners and the gross 
area for headed studs that are welded to a base plate."  
The 2000 IBC states in section 1913.5.1.2 calculates the 
tensile strength of anchors using equations 19-5 and 19-
6 that include the variable Ase which is defined as 
the "effective cross-sectional area of the anchor."

Therefore, it seems as if for concrete anchorage design 
that one should use the net tensile area, not the 
nominal area, that is shown for bolts in AISC "Steel 
Construction Manual".

> No, they both say that for the fasteners tabulated, the
> strengths/stresses given are based on the unthreaded area of the bolt.
> Ab is defined in ASD Spec. Section J3.4 and 3rd Ed. LRFD Spec. Section
> J3.6.
> 
> The 2000 RCSC commentary has a good discussion of this. It says that the
> design values account for a tensile stress area = 75% of the unthreaded
> area. 
> 
> HTH,
> 
> Heath 
> 
>  
> > -----Original Message-----
> > From: utej(--nospam--at)attbi.com [mailto:utej(--nospam--at)attbi.com]
> > Sent: Monday, October 14, 2002 3:14 PM
> > To: seaint(--nospam--at)seaint.org
> > Subject: Tensile capacity of threaded rods
> > 
> > Does it state anywhere in the AISC "Manual of Steel
> > Construction ASD" (Ninth Edition) that one should use
> > the Tensile Stress Area when determining the allowable
> > tensile capacity of a threaded rod or at the threads of
> > a machine bolt?  If so, why do they show a table
> > entitled "Threaded Fasteners Tension of Gross Area"
> > (AISC pg.4-3, Table I-B)  in lieu of providing the
> > allowable tensile capacity based on the Tensile Stress
> > Area?
> > 
> > Does it state anywhere in the AISC "Manual of Steel
> > Construction LRFD" (Third Edition) that one should use
> > the Tensile Stress Area when determining the allowable
> > tensile capacity of a threaded rod or at the threads of
> > a machine bolt?  They provide Table 7-14
> > entitled "Design Tensile Strength of Bolts" based on the
> > nominal bolt diameter (not the threaded portion.
> > 
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