@BAretired the isometric sketch is a little rough.
The L-frame vertical legs are closer to the center of the channel and have rungs in between to act as a ladder for people coming up and down from the work area. So, the channel was used to span between the WF beams and the L-frame connects to that.
So the shear in the channel is applied at the shear center with a moment arm to the center of the L-frame vertical leg. This causes a moment which should equal the moment demand on the L-frame. Since the shear is applied at the shear center, there is no torsion on the channel. As long as the...
The two L-frames are welded close to the center of the channel along its span.
So essentially, the moment arm for torsion will just be from the face of the channel to the shear center?
I analyzed the bottom horizontal leg of the L-Frame as a beam with a fixed end and a pinned end and was...
ASCE 7 specifies 40 PSF for catwalks which is what this platform acts as but I'd rather check it for a higher point load just in case.
The WF beams (green) support an existing work area.
The channel (red) spans between the WF beams (green) and is welded to a built-up L-Frame (blue).
The L-Frame...
Unfortunately, the geometry makes it difficult to find another support for the platform.
The workers have to come from up and then down onto the platform.
I added some markups to the sketch.
I am analyzing the supports for a small access platform (4x4). Maybe two workers on it at the same time with some equipment so max load is say ~ 2 kips.
The platform is supported by a welded L-frame and a wall. There are two of those frames per each platform.
The channel is welded to the frame...
