Steel Fabrication - Bending 1/2" Plate no big deal?

[JoelTXCive]

I have a metal fabrication shop question.

I would like to put some ~45-degree bends on 1/2" thick 36ksi plates. The plates will be ~6" wide and maybe 12" long.

Is the 1/2" material getting too thick for the bending brakes a normal fab shop has onsite?

Or, is bending the 1/2" no big deal. (I don't want the contractor telling me I'm making crazy requests (...again)).

Thank you.

 

[DrZoidberWoop]

1/2" plate is not a problem at all for most shops. Your minimum inside bend radius is going to be around 3/4" (AISC Table 10-13). It may be tricky if they are being bent parallel with the 12" side, because 3" on each side of the bend doesn't leave much room for slippage on the break press and will have a relatively small straight-length outside of the radius.

Edit to add: Funny enough, the book-ends on my shelf at work are 1/2" bent plate scrap.

 

[JoelTXCive]

Thanks DrZoid -

That was great input; and I'm sure those are some great looking book ends!

Below is what I have come up with so far. I have not done all the math on the welds yet, but I think this will work. I want to transfer my load to the sides of the HSS section versus the bottom; and I think the bent plates will get that done.

A secondary safety line for a winch that holds up a flood control gate will attach to the eyehole.

 

[dik]

Why not use BAR 1/2" x 6" stock?

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[JedClampett]

You're asking for the ID if the plate bend to match the OD of the HSS.
Maybe, but it seems that most bent plate I get is pretty rounded.

 

[JoelTXCive]

Dik - I'm not following. Are you talking about welding an extended plate directly on the bottom of the HSS section? I thought is was better to deliver the load to the sides. I can get a many more inches of weld.

Jed - The bend radius of the plate (bar) does not have to match the HSS exactly. I think it just visually appears that way in CAD. On the plate bending, I just want to get to the center point of the HSS as quick as possibly. I have a little out of plane loading on the eye, so the longer the plate; the longer my moment arm will be on the weak axis of the plates.

 

[GC_Hopi]

Can you just put a plate and weld directly to the HSS? You can lengthen the plate to get the weld length you need.

 

[dik]

Something like...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[Aesur]

I like GC_Hopi's solution however I would use a WT section instead of 2 flat plate welded together.

 

[CANPRO]

Joel, nothing crazy about what you're showing there for a bent plate. Could be done no problem at the shop where I work. I agree with squaring off the sides like dik suggested...if there are lots of these it would just make it easier to bend a longer piece of plate and cut the tabs to length from that with minimal waste.

To add to the other suggestions - if the orientation of the hole relative to the HSS isn't critical I'd suggest turning it 90deg like shown below. The other suggestions for the plate on the underside of the HSS or a WT could be made to work, but personally for situations like this I prefer to the keep the loads in the plane of the plate(s) and as direct as possible to the side walls of the HSS. The suggestion below would be much easier (cheaper) to fabricate than the bent plate option.

 

[structSU10]

I second the WT concept and have done similar before - its a simple cut to length, add a hole, and flare bevel weld.

I think the inward force from the angle plates putting a transverse compression into the bottom of the tube would need to be considered and any prying that adds to the welds.

 

[JoelTXCive]

I just saw these most recent posts. Thank you very much for the input.

Ya'll have come up with some really good ideas.

Dik's idea is good on changing the bent plate to just a straight 6" wide.

Canpro - I like your's too. I had not thought about flipping the orientation. I should have thought of that because it gets rid of my out of plane bending.

GCHopi & StructSU10 - I like the WT idea also.

I've gotten comfortable with my design, but I don't think the project is going to bid for several months; and it definitely won't be built until 2022; so I have time to tinker with it.

 

[dik]

I'm partial to using the T section approach myself... I think that's the best one.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[desertfox]

Hi JoelTXcive

Yes I think the plate can be bent fairly easily however what is the wall thickness of the box section you are welding to?


“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein