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RE: Truss Connection

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I have a similar situation on a school that I am working on.  My top chord is a W but I changed my bottom chord to a TS to more easily get to KL/r of 300.  

-----Original Message-----
From:	David Carpenter [SMTP:dca(--nospam--at)]
Sent:	Monday, February 09, 1998 1:57 PM
To:	seaoc(--nospam--at)
Subject:	Truss Connection

I am designing a 45' span steel truss for a middle school multipurpose 
room.  The roof pitch is 7/12 and the spacing is 7' O.C.  The architect 
desires a very simple truss in which the span of the bottom cord is 1/2 
the truss span.  Code requirement for tension members in this application 
is for an l/r of 300.  This results in a large bottom cord.

AISC states that " The connections at the ends of tension or compression 
members in trusses shall develop the force due to the design load, but 
not less than 50% of the effective strength of the member, based upon the 
kind of stress that governs the selection of the member."

The design force in the bottom cord is 12 kips.  The capacity of the 
bottom cord in tension is 292 kips.  Designing the bottom cord connection 
for 146 kips seems absurd. Does anyone have any incite on this code 
requirement or suggestions about how to proceed?