I had been told that thick plates are not always straight and their
interface with the column end may not be perfectly continuous. I think this
is the reason for possible milling requirement. The main reason I would stay
away from them, if I could, is the lamination problems and pre-heating
requirements. I just don't believe that, with exception to few situations,
that we should be limited to using too thick of a plate to have to deal with
all of this.
From: Sprague, Harold O. [mailto:SpragueHO(--nospam--at)bv.com]
Sent: Thursday, June 15, 2000 10:09 AM
Subject: RE: base plate software
Re: Ghassem Khosrownia's response:
Why do base plates need to be milled?
Regarding Paul Ransom's response:
Most base plates are drilled with a standard or core drill (low tech) or
some of the new CNC equipment cuts holes with plasma arc. The kerf on the
new plasma arc cutters (a problem at one time) is minimal and is accounted
for in the cutting operations. Punches, although still widely used, are on
the way out. I have never seen a base plate hole punched or reamed. I
imagine that it can be done. I just have not seen it.
For economics I would look at Thornton, "Designing for Cost Efficient
Fabrication", Modern Steel Construction, February 1992. From this you will
find the "rule of thumb" one pair of fillet welded stiffeners is worth 200
pounds of steel.