Floor Truss Chase
Floor Truss Chase
(OP)
When press plate floor trusses are manufactured with a chase at mid-span does the truss act like a vierendeel truss at that location.
I recently looked at a 60' glulam parallel chord truss where the structural engineer wanted to create a square opening in the truss at mid-span. His argument was that the shear is low at that location so that you don't need a diagonal web.
I thought that if you designed a truss assuming that all the webs were pinned at the panel points, that you would create an unstable truss by removing one of the diagonal webs.
However, I have seen press plate floor trusses with chase in the middle. Are the truss designer's relying on joint rigidity to make this work?
I recently looked at a 60' glulam parallel chord truss where the structural engineer wanted to create a square opening in the truss at mid-span. His argument was that the shear is low at that location so that you don't need a diagonal web.
I thought that if you designed a truss assuming that all the webs were pinned at the panel points, that you would create an unstable truss by removing one of the diagonal webs.
However, I have seen press plate floor trusses with chase in the middle. Are the truss designer's relying on joint rigidity to make this work?





RE: Floor Truss Chase
RE: Floor Truss Chase
woodengineer
RE: Floor Truss Chase
RE: Floor Truss Chase
Calculate what is the maximum shear transfer required at this point due to uneven loads.
This load gets transferred over the opening by double curvature bending(as if it was fixed each end).
Check the chords under this bending combined with the axial chord force for this load case.
This method is also useful for penetrations in concrete beams.
csd
RE: Floor Truss Chase
RE: Floor Truss Chase
woodengineer
RE: Floor Truss Chase
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RE: Floor Truss Chase