Angle Iron Stress

[komet99]

I have a project at home in which I am building ramps from angle iron. The current idea is steel 2"x2"x1/8" 5' long. How much weight will 1 length of this angle iron support?

Dale

[RWOLFEJR]

Hi Dale and Welcome to the forum.

Without any calculations I'll tell you one piece standing alone won't handle much before it'll start twisting. Pair it up with another angle and now you have effected a channel or a T beam which will handle a good bit more. You don't really need to know what one piece will handle. You need to know what the entire structure will handle. The amount that two angles tied together will handle is a lot more than twice the load a single angle can carry. The geometry has a big effect.

Was at a big aution and watched a guy with some home-made ramps back off a good sized lawn mower out of his high 4x4 pick-up. As soon as a decent part of the weight got on the ramps they collapsed and the tractor and he flipped over backwards and to the side. Lucky he wasn't killed.

There are more things to consider in designing ramps than the load they'll carry, and most on this site will be reluctant to tell you what to make them out of for fear of the unknowns. Weight... application of that weight... angle of the dangle... potential for shock load or bouncing... welding or bolting and how good or how many... etc.

With more information could possibly help you out. Also there are calculators on this site that make doing the calculations quick and slick.

And sometimes it's best to just go out and buy things designed for the purpose?

Good luck and be careful,
Bob

[Kelly_Bramble]

I'm with Bob - be careful..

Here are some helpful links so that you can estimate deflections, etc..

https://www.engineersedge.com/beam_calc_menu.shtml

https://www.engineersedge.com/analys...ety-review.htm

https://www.engineersedge.com/mechan...ial_menu.shtml

https://www.engineersedge.com/sectio...ies_menu.shtml

[PinkertonD]

Hi Dale, welcome to the forum, and I hate to also rain on your parade, but Bob is correct and I am with him 100%. With things like ramps, there may be a little cost savings over buying a set, the risk factor is totally out of sight.

Please also be cautious of other forums staffed by home-shop builders. This is one of a very few forums on the Internet where there are a significant number of qualified and experienced Engineers, and I mean Engineers with many, many years experience. I have about 40, Kelly probably the same, Bob is playing catch up but not far back.

IF you are still hell-bent on doing it yourself, then make sure you consider "crowning." That is the point where the ramp meets the trailer and creates an angle. The peak of that angle needs to clear the belly of the thing being driven/pushed/dragged onto the trailer.

Finally, IF this is for a wheelchair ramp, then just DON'T. It is bad enough for someone to be in a wheel chair without one side of a ramp failing and they get tossed into the rocks for some serious head injuries or worse.

See Harbor Frieght
Ignore the idiot who left a review about them being heavy. They carry 500-lbs EACH and that is exactly what Bob and I are talking about. They need to be strong and that makes them heavy. Also note that they have two humps that will help overcome the crowing problem I mentioned. As a plus they have safety chains to prevent slip back. For under 100-bucks it is a no-brainer to me and I have an extensive machine shop at my disposal. I would be buying.

[jboggs]

For what its worth, here's another silver-haired old fart with a fair share of both successes and failures over 35 years (you learn from both!) in professional engineering design - Ditto above. Buy, don't build.
Get the benefit of someone else's "trial and error", rather than suffering through your own.

[Kelly_Bramble]

These are nice -->

Also, they have twenty plus versions to choose from..

[PinkertonD]

Ooops, sorry JB, When I wrote that I knew there were four I wanted to mention but this old fart was not through enough morning coffee to be sure enough that you too were on the OF gathering. Did not want to insult a young man.

[jboggs]

Your memory is better than mine! I can't remember what I had for lunch.
My daughter gave me a plaque as a "Founding Farting Father of the Old Farts of America", or the F.F.F.O.F.A. as its known in our house, so I guess I qualify.

[greg_davis]

For what its worth, here's another silver-haired old fart with a fair share of both successes and failures over 35 years (you learn from both!) in professional engineering design - Ditto above. Buy, don't build.
Get the benefit of someone else's "trial and error", rather than suffering through your own.

But what if no one has built it before? I want to hang as much of the weight as possible (of about 800 pounds total weight) of a solar panel system on the parapet instead of on the flat roof with a clamp design on to the parapet (no drilling holes through the stucco or roof). 20 panels would be about 13' long and 27' feet wide. There would only be about 3 vertical feet of usable parapet. The top and vertical wall of the parapet (including both sides of the parapet as it will c-clamp over the top) can support some of the weight but how much until it crunches through the stucco and wall board of the parapet (I am assuming there are 16" centered 2x4's inside the parapet with plywood, tar paper, chickenwire and stucco over it)? The rest of the weight would be on the feet at the other end of the wide side (13' out) on the roof which I figure the weight alone would keep that side down (no need to anchor into the roof). The clamp onto the parapet would keep it from moving in high winds. No drilling, no holes, no leaks possible. And since the buildings I have in mind for this have an elevated flat roof on one part over the main room the parapet clamp will not be seen from the outside as this parapet is in the middle of main roof and too far away from the side of the building to be seen. I am not an engineer, so I have no idea if this can work or not.

[administrator]

The original thread has not been active since 2012... Not sure you will an answer given that there are so many unknowns is your design, application and the age of this thread..