Steel Angle Bending/Splitting 1

[ryaneng]

Hi all,

I'm reviewing some drawings from a steel manufacturer for some steel framing around a roof opening in a metal deck roof. The metal frame will rest on OWSJ's, and support the roof deck around the opening. What they've submitted doesn't match our details, but I do think it's a much easier construction, and could work in some situations. Our detail:

https://files.engineering.com/getfi...890-48f7-af01-88d809d9d08d&file=Capture_1.PNG

Their drawing:

https://files.engineering.com/getfi...154-407f-9d34-3661daee18ce&file=Capture_2.PNG

My main concern is the point where the flat steel angle portion meets the vertical web of the angle. The flat plate has enough bending capacity without the vertical, but what resistance does the member have to splitting where they join together. I think an easy fix is to simply add in a gusset plate where the vertical starts (or revert completely to our detail), but I think their detail is nice for constructability and I would like to use it in certain low load applications if I can prove it works.

What are your thoughts? Am I missing something, or is there a straightforward check I can complete? Typically when members like this are coped the shear resisting vertical web is what remains...

 

[human909]

Ok I'm modelling it now. I am not quite clear on the right hand support condition and where you want the loading. Also I'll need you address to send my invoice.

(oh and I charge double when somebody gives me non metric units!, but for time I've got I'll do inches)

 

[KootK]

I am not quite clear on the right hand support condition and where you want the loading.

It doesn't really matter. All of the action will be at the left support and and the first few beam depth worth of length into the beam proper. Whatever's easiest for you really. If you'd prefer to do an 8' beam with the right end sitting on a column and a point load in the middle, then so be it. As I mentioned previously, I'm just trying to pare it down to the bare minium to make it easier to separate the wheat from the chaff.

 

[KootK]

Ok I'm modelling it now.

Truly, there's no rush. Take days, weeks, months... I still have to sketch my my "proof".

 

[human909]

I'm not feeling rushed. But if I don't get it done now, I will lose my enthusiasm and it won't get done. I'll do it now. I'll keep you updated as a quick back and forth is much more efficient.

As I mentioned previously, I'm just trying to pare it down to the bare minium to make it easier to separate the wheat from the chaff.

Got it.

And it is good practice for me to help get my head around some of the finer aspects of the FEA modelling and interpreting the results.

 

[human909]

Principle bending stress:

 

[human909]

I can't figure out the suitable shear stress. It could be my use of the software, but more likely it is my poor conceptual understanding of stress planes/tensors/mohrs circles. It makes my head hurt. I figured I need ZY shear stress but I don't have that choice.