Thanks Charlie. While I had found some examples which showed the Whitmore
section on a diagram like the one you referenced, there was no text to go
with it to explain in detail how the Whitmore section is determined. While
it is often true that "a picture is worth a thousand words", in this case I
needed some words to go along with the picture. The article on gusset plate
design which I downloaded from the "Steel Tips" was quite helpful in adding
an explanation of the Whitmore section. (Although the explanation of "When
you get to the end of the connection, the Whitmore width is the width to
which it has spread" is not explicitly clear. The end of the connection
appears to be the last row of bolts in a bolted connection vs the end of the
In any case, I would recommend that AISC include an explanation of the
Whitmore section in future issues of the Connections manuals. The current
versions seem to expect that the reader already understands what the
Whitmore section is.
From: Charlie Carter [mailto:carter(--nospam--at)aiscmail.com]
Sent: Friday, February 02, 2001 6:25 PM
Subject: RE: Steel gusset plate design
If you look at LRFD Volume II page 11-29, the Whitmore section is
illustrated in Figure 11-11b. Essentially, the Whitmore width is determined
by spreading the force out of the connection at it's start 30 degrees to
each side. When you get to the end of the connection, the Whitmore width is
the width to which it has spread. Multiply the width by the thickness and
you have the area. To determine the appropriate critical buckling stress for
use with that area, see the discussion under "Comments" on page 11-42.
A more simple illustration of the 30-degree spread for a Whitmore section is
shown on page11-15 for a tee hanger connection.
Hope this helps.