Truss modeling in RISA
Truss modeling in RISA
(OP)
I am modeling some existing existing truss in RISA. I have always thought that truss members should be modeled with pin connections. The existing truss is completely welded. So, should I still model this as pin connected? Also, I only have hand sketches of these trusses and in one of them all of the diagonal web members are in the same direction with vertical members between them like a howe truss with all the diagonal members in the same orientation. I know that truss webs usually are triangle for tension and compression but even with welded connections it just looks like it the parallel top and bottom cords would not be adequately supported by the web members. Thoughts?






RE: Truss modeling in RISA
As far as the second question, the truss will be fine, but your verticals will see forces (stresses). For other trusses many of the verticals are zero force members.
No harm in doing this truss by hand. It's actually pretty easy. Then use RISA to check your work.
RE: Truss modeling in RISA
Mike McCann, PE, SE (WA)
RE: Truss modeling in RISA
RE: Truss modeling in RISA
I can see how it would be conservative for the members to consider everything pinned. I'm not sure whether that would be conservative for the connections or not.
RE: Truss modeling in RISA
Mike McCann, PE, SE (WA)