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Tension Field Action - End panels in Old Codes

Tension Field Action - End panels in Old Codes

Tension Field Action - End panels in Old Codes

(OP)
I am working on a power plant project with some deep plate girders designed back in 1976 (or before). From the drawing reactions and loads I have determined the original engineer must have considered tension field action for the shear capacity.

The issue I have is that several of the plate girders are framed into other girders using clip angles. So the on the end bays there is only a stiffener on one side. According to 360-10 TFA can not be used on end bays. Looking back at Blodgett's he gives a stiffner spacing and depth limit for end panels. Implying to me that TFA was allowed on end panels at that time. I don't see anywhere in Blodgett an exclusion from using TFA on end bays.

Can anyone confirm that the limits of using TFA on end bays came in the code after 1976?

RE: Tension Field Action - End panels in Old Codes

The contribution of tension field action to the load carrying capacity of plate
girders has long been recognized, beginning with the work by Basler (1961).
Unfortunately, tension field action is limited to the interior panels of plate girders
in the AASHTO (2009) and AISC (2005) codes as shown in the work by White
and Barker (2008) and White et al. (2008). Recent work by Yoo and Lee (2006)
demonstrates this assumption is too conservative and points out that tension
field action is possible in the end panel of steel plate girders. More importantly,
the recent edition of the Guide to Stability Design Criteria for Metal Structures
(SSRC, 2010) provides one possible detail for end panels designed for tensionfield
action, however experimental evidence supporting this detail is limited. The
contribution from the composite deck slab and girder (Shanmugam and Baskler,
2003) should also be explored.


http://www.dot.ca.gov/newtech/researchreports/preliminary_investigations/docs/pi_of_plate_girder_end_panel_shear_resistance_oct-28-2010.pdf

And looking through AISC 9th edition (1989) for conformation, I don't see the limitation there. So to answer your question: it likely came in after '76.

RE: Tension Field Action - End panels in Old Codes

Here's what I came up with in reviewing all my old AISC specs:

1951 Fifth Edition manual - 1946 specification
Plate girder design requires intermediate stiffeners for webs with h/t <=70
No mention of end panels.

February 1969 spec (7th Edition Manual)
Tension field action permitted by use of Equation 1.10-2
Not permitted for hybrid girders (i.e. flange and web of different steels).
Spec states: "In girders designed on the basis of TFA, the spacing between stiffeners at end panels and panels containing large holes shall be such that the smaller panel dimension, a or h, shall not exceed 348t/sqrt(fv)"

November 1978 spec (Eighth Edition Manual
Tension field action permitted by use of Equation 1.10-2
Spec states: "In girders designed on the basis of TFA, the spacing between stiffeners at end panels, at panels containing large holes, and at panels adjacent to panels containing large holes shall be such that fv does not exceed the value given by formula (1.10-1)"
Formula 1.10-1 is the base fv formula for plate girders without tension field action.

June 1989 spec (Ninth Edition Manual
Tension field action permitted by use of section G3
Spec states: "In girders designed on the basis of TFA, the spacing between stiffeners at end panels, at panels containing large holes, and at panels adjacent to panels containing large holes shall be such that fv does not exceed the value given by Equation F4-2"
Equation F4-2 is the base Fv formula for plate girders without tension field action.

September 1986 spec (First Edition LRFD Manual)
Tension field action permitted in section G3
Spec provides for plate girder design in Appendix G.
Equation (A-G3-1) provides for Tension Field Action except:
"for end-panels in non-hybrid plate girders, for all panels in hybrid and web-tapered plate girders and when a/h exceeds 3.0 or [260/(h/ts)]^2. In these cases tension field action is not permitted and Vn = 0.6Aw(Fyw)Cv"

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RE: Tension Field Action - End panels in Old Codes

(OP)
Thanks for the quick input everyone.
It looks like end panel TFA was allowed (within limits) back in the mid 70s.

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