DESIGN STANDARDS FOR TRAILER STRUCTURES

[rlewistx]

I'm doing some preliminary research on what is required to design parts of a structure that will be used on public roads. Specifically, I'm considering parts of a trailer used for oil field equipment transportation. I'm assuming there must be some designed standards that are geared specifically for highway vehicular movement. Are there such, and if so, what documents should I look at to get an idea of the requirements?

Thanks for your insight.

Rich

 

[Lugo331]

You can start with the Department of Transportation federal regulations. They have all the regulations on length, width, height, and weight. Going from memory but basically:65 ft combined truck and trailer, 102" wide max, 13'-6" max height, 80,000 LBS max combined weight, 34,000 max on each of the drive and trailer tandems, 40 ft max bridge from king pin to center of the rear most trailer axle. I build semi trailers for car haulers which fall under some different exemptions so you should double check everything. Paul

 

[rlewistx]

Thanks for this information.

I think what I'm most interested in is design standards, such as what allowable stresses are permitted, how much impact force must be included in the design for running over bumps or holes, wind influence, load combinations, etc. I'm okay with static design. Once objects start moving there is a whole new set of loads.

I'm mostly looking for information so I can convince others that this is a specialty field and a typical structural engineer should not be working in this area unless they are familiar with these required standards.

Thanks.

 

[Lugo331]

In the oil field industry we used a rule of thumb of twice the calculated static stress to allow for dynamic loading. Paul

 

[rlewistx]

Thank you for your feedback. This seems to me to say the same as cutting the allowable stresses in half. Am I missing something?

 

[Lugo331]

If we were mounting a component like a diesel motor we would design all the supports, fasteners, weld joints, etc. for twice the actual weight. This would account for bumps, pot holes, and emergency stopping. Paul