Subject: Re: 125' long steel truss, connection question
Date: Fri, 25 Jun 1999 02:57:36 EDT
In a message dated 99-06-23 20:00:25 EDT, you write:
<< Simon Solorio >>
I'm designing a 125' long steel truss, a section view of the truss is a
triangle. The top chords (2 top chords) are pipes and the bottom chord (1
bottom chord) is also a pipe. The web members are pipes.
1. the top and bottom chords are going to be a continuous pipe, so when I
analyse the truss should I assume the connection at the node intersections
(at the chords only) fixed or should I analyse it assuming the the chords are
pinned between each node of the truss?
2. the pipe web members are going to welded to the pipe chord members with
fillet welds, where can i find information on how much fixity i should design
Thank you in advance
Simon Solorio, P.E
A quick question on your computer model.
If you model your chords as pin at the connection node then doesn't one of
the web members needs to be fixed to provide some rotational rigidity. If
all the members (chords and webs) framing into a node are pinned(no
rotational rigidity) the analysis program should give you a warning or error.
Is this not the case?
Or maybe I misunderstood.
The two cases you want to check are:
The first you consider the chord continuous and have all the web members
pinned at the node.
The second is you have the chord pinned at the connection and want the web
members to exhibit some rotational rigidity, maybe with a torsional spring.