Trailer Design Information û I need some! 1

[Dynamike]

I was wonder if any one can help me. We are looking into designing and manufacturing our own tandem and tridem truck trailer for carrying up to 20-60k lbs of pressure vessels and piping. We are currently buying a flatbed-goose neck but would like to design a better trailer of our application and loading conditions. I have searched hi and low on the net only to find no books or papers to help us. Basically we are concerned with the strength of the frame base on our loads and how bouncing down the rad with affect it. Also any other information on axle sizing, brake requirements and anything on the topic would be very great full.

Any suggestion where to start would be most helpful.

 

[patprimmer]

What's wrong with studying existing products designed to carry similar loads.

I believe axle/brake systems are load rated when sold.

Local traffic authorities will also have some rules, regulations and guidelines.

If your load application points can be controlled, look at shipping container trailer designs and timber jinker which are designed to carry logs.

If your load will be evenly distributed or randomly applied, look at general flatbed designs.

Regards

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[zeusfaber]

From what I've seen of the heavy trailers business, there's always a lot of "blacksmithing" involved - the sort of stuff where experience is as important as analysis.

I've certainly seen all manner of fancy structural analysis utterly fail to predict the ways in which a heavy stepframe design consistently falls to bits when subjected to the rigours of real life - and this is the kind of product where something going wrong is likely to hurt.

There are lots of really good bespoke trailer makers out there who will almost certainly do a better job, closer to first time, for less money and with better after-sales support than you could hope to achieve with an in-house one-off.

My temptation here would be to outsource unless there was a compelling reason not to.

A.

 

[Greenlight]

We put accelerometers inside 53 ft. trailers and found that the cargo inside the trailer experiences 2.5 to 2.8 vertical g's when traveling over US highways.

Make sure and account for these additional loads in your calculations.

 

[jbthiel]

I dito Greenlight. I think your biggest problem is going to be long term fatigue but you don't know what your load conditions are. Since the number of fatigue cycles will be very high, you will need to keep the stresses very low.

Another thing to consider, depending on how you restrain your load, is fatique due to frame twist. I have seen many dirt hauling trailers/ dump trucks with diagonal patches added.