Why is it sometimes impossible to shut the trailer doors on sloped ground?

The correct response of unsatisfactory is the correct response as the questioner cannot fathom the simplicity of the angular conundrum being the result bearing a quasi-irrational expletive deleted response.
The elliptical angle of sloping structure shall consistently afford a non structural impairment relative only to ones' semi-conscious state regarding vast quantities of unknown as well unseen forces bearing a grudge upon less than solid forms (your brain matter) rendering comprehension null and void in complete breakdown of such mental capacity for formal education and awareness to natural conflagrations of Nature.
Any further description shall be deemed irrelevant......yet We're sure shall continue to be questioned.

Please reference "The Bible of Angles", available wherever finely tuned Tomes rest.

 

I was.
It's actually not the weight of the roof that's critical. As the center of the trailer sags, the walls also need to sag, effectively the top of the wall sheet needs to be shorter in length than the bottom if the wall sheet is to remain a plane sheet. (A plane has only two dimensions.) But there's an easier way for that to happen than deforming the wall sheet within the plane, which requires deforming metal: The wall will bow in a curved sheet. And this is where the roof carries some of the load on the trailer, it constrains the side wall, keeping it close to a plane. Surely you've seen the wrinkles in the skin of a heavily loaded trailer? The roof looks very similar.

The floor of a box trailer isn't strong enough to hold the weight of the load itself, it wants to bow down. But the side wall prevents that bowing down because it wants to remain a plane. And since it doesn't have the structural integrity to resist bowing on it's own, the roof carries some of load by holding the sidewall in a plane. Every part of the box provides needed strength to maintain the shape of the box which allows all the parts to carry some of the load. Think about how much stronger a cardboard box is when taped shut versus the top just folded together.

As the box structure sags (It's not much, but it's there.) the top of each end moves slightly closer to the center of the trailer. But that's fore and aft, and that doesn't deform the square rear frame like torsion would.

You're making this entirely too complex. Stand behind the trailer, are the truck and the trailer on the parallel slopes? If so, there is no torsion being introduced into the trailer structure, and as such, no deformation of the rear door frame.


And for y'all wondering why I'm bothering? There's no such thing as too much knowledge, and so I'll share what I can provided it's not a complete ####show of a thread. Someone might find it useful. Sort the same thing as my winter threads; most drivers could care less to understand the whys behind it, but if it helps the few who do care, it was worth it.

 

So can anyone confirm if the OP ever got his doors closed? I feel like we all deserve some closure here.

 

I don't think trolls have thumbs. It makes opening and closing doors very complicated whether they're on flat ground or not.

And no I didn't read this entire thread to see if that answer has already been given...I tried to, but I just couldn't get past page one. I honestly can't believe I made it that far.

 

You are one of the lucky ones. Once you make it to page 2 or 3 you get expedite_it'ed into the matrix and you don't make it out.

 

How do you think *I* feel? I've had to study his entire technique to mimic it. Lol

 

I applaud you for your sacrifice.

 

Don't know if deserve praise or to be slapped for that

 

Slap me then praise me. I pay a couple hundred a pop for that kind of treatment.

Then we say "my what a lovely tea party" and I drive home.