Feedback on Welded Aluminum Trailers

[MMcCawley]

Hi all,

I know there are many differing opinions on Aluminum vs. Steel trailers but I was hoping for some opinions from those that have welded aluminum trailers (versus bolted). As an Engineer who has worked with a fair bit of aluminum I know how soft it becomes in it's annealed state (at the weld joints post welding). I'm assuming these trailers are made out of 6061-T6 which is overall a great choice but how do they retain there strength at the weld joints after welding? I'm assuming the majority of the trailer manufactures aren't retreating the trailers (would need a fairly large oven). Are there any issues with cracking/breaking at the weld joint?

Thanks,
Matt

 

[Blitzn]

I am wondering similar about steel or aluminum trailers. Do you have any advice as to which way to go?
I've heard from some all negative about aluminum (adjustable bunks, oxidation), and from others (custom bunks steel stronger) all positive.
As a Structural Engineer - I wonder the same - regardless of the material if properly sized it should load within the elastic region and then regardless of material perform the same.
recommendations?
Thanks.
-Dennis

 

[Henry Boyd]

Dennis,

You are right. Many people believe (wrongly in my opinion) that aluminum is better than steel. In fact both with proper sized materials perform equally from a structural standpoint. On commercial frame trailers (not monocoque van designs), aluminum may be 'lighter', but the first cost premium paid for aluminum can never be recouped no matter how crazy diesel prices get.

On boat trailers, a good hot dipped galvanized trailer will last as long as you want it (from a corrosion standpoint). I have a number of friends who are going into their second decade with galvanized trailers that are used regularly in the ocean. This in my mind makes the premium paid for aluminum senseless. I agree the aluminum trailer will be pretty for a longer period of time. But if you aren't trying to overstep the ability of your towing vehicle, and can stay within safe & legal gross weight limits with a steel trailer, that's the better choice.

As a bit of warning/advice; if you have only worked with static structures be careful when applying your 'rules of thumb' to dynamic structures like trailers. The dynamic conditions will significantly affect these assumptions.

Henry

 

[Blitzn]

Dennis,
As a bit of warning/advice; if you have only worked with static structures be careful when applying your 'rules of thumb' to dynamic structures like trailers. The dynamic conditions will significantly affect these assumptions.
Henry

For lateral reinforcing, the same "rule of thumb" applies for flexural and axial forces - in fact they become more critical under dynamic loading as "beam rolling" comes into affect. I won't begin to delve into designed for failure mode analysis and "dog-bone" plastic deformation zones. :lol: