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Re: Truss Connection

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At 11:56 AM 2/9/98 -0800, you wrote:
>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?
>
>

AISC ninth edition page 5-63 states:

  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,....

 " ...unless a smaller percentage is justified by engineering analysis that
considers others factors including handiling, shipping and erection"