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Re: Shear-off bolted connection

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Would be great if anyone who knows the exact source of this article, or know
of any article about such techniques in a structural engineering journal
gives us the reference.

Majid Sarraf

At 02:15 PM 1/20/1999 -0600, you wrote:
>For anyone interested in talking with manufacturers about gauging tension,
>it seems to me that (like a guitar string) the tighter the bolt is - the
>higher the frequency it would give off.  I seem to remember an article in
>NASA Tech Briefs about gauging bolt tension with ultrasonics - might be
>worth looking into.
>                                                                Greg Smith
>-----Original Message-----
>From: WILLIAM R. KEEN <wrk(--nospam--at)>
>To: mail@ih {seaint(--nospam--at)} <seaint(--nospam--at)>
>Date: Monday, January 18, 1999 1:22 PM
>Subject: RE: Shear-off bolted connection
>I think we need to balance the theoretical aspects of this issue with the
>practical aspects. Erectors and fabricators are telling us they like the
>twist-off bolts because they are easier to install and they can maintain
>higher quality. Usually, if it's hard to do something in today's
>industry, there's very little likelihood that it will be done well without:
>a) a LOT of involvement by the SER,
>b) more field inspection,
>c) a contractor who cares about quality and
>d) someone with enough chutzpa to tell the contractor it's not right and do
>it over again
>I agree with Charlie - they all CAN perform well if installed properly. The
>question is, how hard is it for all parties involved to make sure that
>I like the twist-off bolts. I've experienced problems with DTIs myself. The
>biggest problem I've seen is that they "squish" too late in the torque
>process and bolts break off. Over-tensioning worries me more than
>under-tensioning. I'd much rather have a bolt tensioned to 50% of proof when
>90% was required vs. 110%.
>Bill Keen
>-----Original Message-----
>From: Charlie Carter On Behalf Of Charlie Carter
>Sent: Sunday, January 17, 1999 10:02 PM
>To: mail@ih {seaint(--nospam--at)}
>Subject: Re: Shear-off bolted connection
>It's not surprising that a manufacturer of DTI's would claim
>emphatically that DTI's are the best method. But the facts are that any
>of the four methods approved by RCSC (the Research Council on Structural
>Connections) will provide acceptable bolt installation for pretensioned
>applications when used properly.
>The four methods are:
>turn-of-nut method
>calibrated wrench method
>alternative design fastener method (such as a twist-off bolt)
>direct tension indicator method
>Any of these methods can produce unsatisfactory results if not applied
>properly. All can be used successfully if applied properly. Refer to the
>RCSC Specification (particularly Section 8 and it's Commentary) for a
>discussion of these four methods.

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                   \               Majid Sarraf             /
                    \             Ph.D Candidate           /
                     \   Department of Civil Engineering  /
                      |        University of Ottawa      |
                      |           Ottawa, Ontario        |
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