×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Laterally Unsupported Plate Bending Resistance in Strong Direction

Laterally Unsupported Plate Bending Resistance in Strong Direction

Laterally Unsupported Plate Bending Resistance in Strong Direction

(OP)
Hi,

In a situation like the sketch attached, how would we determine the thickness of the plate? It does not fall into a particular situation as listed in table 4-2 in S16.
Thanks in advance.
 

RE: Laterally Unsupported Plate Bending Resistance in Strong Direction

It is not a very good detail.

I would check shear and bending on the plate.  For factored flexural compressive resistance, I would use Table 4-4 with effective length = 2L +b where be is the flange width of the supported beam.

If there are any horizontal loads parallel to the supported beam, the plate must be designed for bending and the column for torsion...messy detail.   

BA

RE: Laterally Unsupported Plate Bending Resistance in Strong Direction

I meant b, not be is the flange width.

BA

RE: Laterally Unsupported Plate Bending Resistance in Strong Direction

The single knife plate bothers me here.  I would go with two plates of the same or greater thickness mounted to the side of the tube section, two thru-bolts for erection only, and field welding of the two plates to the tube.  The plates could be shop welded to the WF beam.  

The kicker on the WF is a good idea for the torsion to the beam.   

Mike McCann
MMC Engineering

 

RE: Laterally Unsupported Plate Bending Resistance in Strong Direction

The latest AISC specification does include allowable stresses for flat bars bent the hard way.

RE: Laterally Unsupported Plate Bending Resistance in Strong Direction

As JStephen mentions, section F11 from AISC 13th (or 14th edition) contains these formulas.

Mn = Cb*(1.52-0.274*(L*d/t^2)*Fy/E)*My < Mp
or
Mn = Fcr*Sx = 1.9E*Cb/(L*d/t^2)*Sx

 

RE: Laterally Unsupported Plate Bending Resistance in Strong Direction

consider the compression side as a flat plate buckling under a direction compression load.  for me the allowable works out at something like .4*pi^2*E/(12*(1-v^2))*(t/b)^2 = 0.36*E*(t/b)^2.  for b, i'd assume a distance (30t?), get an allowable, get the bending stress at the mid point, get an MS; then again for 1/2 the effective width (the allowable and the average bending stresses will both increase, but does the MS decrease ?)

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources