How much force until I screw this up?

[jdh239]

Don't know if there is a good site for this on the web somewhere. I know some have some CAD software that can specify this, but I don't have it.

If I have a 2x2x1/4" square tube, say 12-14' long (it will be in that range), and the ends are attached to a surface, how much pressure can it take in the middle with a hydraulic ram before I screw up the tubing?

Essentially, I have a 16' span (pergola) that had a lot of snow on it this last winter (almost 2 feet one night while I was sleeping). There is a piece of 6x1" c-channel in the vinyl span that was bent out of shape due to the weight (a few inches). It is pretty thin stuff... not sure what gauge, but I would guess around 16 gauge and galvanized.

Anyway, I want to bend it back to remove the bend in the pergola...... and I was thinking about doing it with a hydraulic ram in the center while having the ends anchored to the beam I wish to bend back toward the ends (where the supports are and where there was the smallest amount of deflection).

Thanks in advance.

[roadkillbobb]

just take a 20 ton bottle jack and a 4x4 and jack till you straighten it, go past level due to spring back and repeat as needed.. no engineering needed

[gwiley]

Bear in mind that after straightening you will have significantly weakened the member. If it was my structure I would add a brace on one side of the channel - otherwise you will see it fail (maybe completely) next time it is subjected to a good snow load or strong wind.

Thin gage tubes and channels love to kink and fracture unless they are bent with a die.

Licking my finger and sticking it into the wind….

The web is doing the all the work here - the legs prevent twisting, so you can probably add a 16ga plate over the web with a reasonable margin on either side of the bend.

[jdh239]

thx. Maybe I can find a long piece of galvanized I can throw in it to help reinforce it.