Perception
Structural
- Feb 4, 2015
- 34
Hello,
I have a few questions on computing the moment capacity of a composite steel deck + concrete slab beam system as follows:
1) If a girder only has simply supported beams framing into it on one side, are the beams considered as lateral bracing points assuming web shear plate connections are used? My understanding is that decking will not provide adequate lateral bracing to a girder since the ribs typically run parallel to the top of the girder.
2) How is the moment capacity of a beam/girder at an angle computed? For example in plan view if a beam is slanted 30 degrees to the horizontal, what assumptions do you make for the direction of the deck across the top of the beam and how much space you have available for shear studs? Can decking be installed such that it's slanted 30 degrees to match the beam?
3) How is the moment capacity of a beam//girder computed when the decking changes orientation over the top of the member? Do you assume either a parallel or perpendicular deck condition and ignore the other deck condition on the member?
4) Is composite design typically considered for concrete slab + steel decking systems with joists? If so, how is the tensile capacity of the joist taken into account when computing the moment capacity of the combined section? Intuitively I think you could utilize the tensile capacity of the bottom chord to compute the moment capacity, but I'm not sure.
Thanks
I have a few questions on computing the moment capacity of a composite steel deck + concrete slab beam system as follows:
1) If a girder only has simply supported beams framing into it on one side, are the beams considered as lateral bracing points assuming web shear plate connections are used? My understanding is that decking will not provide adequate lateral bracing to a girder since the ribs typically run parallel to the top of the girder.
2) How is the moment capacity of a beam/girder at an angle computed? For example in plan view if a beam is slanted 30 degrees to the horizontal, what assumptions do you make for the direction of the deck across the top of the beam and how much space you have available for shear studs? Can decking be installed such that it's slanted 30 degrees to match the beam?
3) How is the moment capacity of a beam//girder computed when the decking changes orientation over the top of the member? Do you assume either a parallel or perpendicular deck condition and ignore the other deck condition on the member?
4) Is composite design typically considered for concrete slab + steel decking systems with joists? If so, how is the tensile capacity of the joist taken into account when computing the moment capacity of the combined section? Intuitively I think you could utilize the tensile capacity of the bottom chord to compute the moment capacity, but I'm not sure.
Thanks