Laurence B. Oeth PE
Lake Oswego, OR
----- Original Message -----
Sent: Thursday, April 19, 2001 12:34
Subject: RE: Bolt Head Pull Through
chance we could get a picture of that? Maybe Dennis will let us post
them on the Structuralist?
always interested in failures and their mechanisms. The general
consensus seems to be that we so over design things that failures never
occur. Having worked in a small office supporting local industrial
plants. We often got called 10 years after the construction when
something broke and the plant was tired of fixing it. About half my time
was spent on these types of projects, so I started questioning that "failures
never occur". Having now worked on the original design side, I
realize what a complete lack of feedback is generated in the system.
"Design" structural engineers don't have lessons learned because they rarely
know when their designs failed.
OK here's an interesting one for your
I'm looking at a failed connection, fab'd
from a 1/4" plate, probably A36, welded to a 1/2-round piece of pipe
(Sch80). 5/8" dia 316SS hex head bolt (no washer) pulled neatly
through the 11/16" dia hole. Very nice, uniform curling down of the
steel all around the hole which enlarged it enough for the bolt to slip
through. This was repeated 2 times each support on about 16 supports
all around a tank. The bolt did not fail, and does not visually appear
to have bent/sheared/necked down.
I shudder at estimating based on energy
methods applied to the deflected shape. Anyone know of an empirical or
analytical report to aid in determining what the force was at
Laurence B. Oeth