Trailer Vessel 1

[PVGuy]

I am designing a horizontal vessel that will sit on two longitudinal beams that will be attached to the vessel for the complete length. I am attempting to find a stress/strain formula for a cylinder with two radial line loads with a angle between them that go down the entire length of the vessel. I am doing this to determine the stresses in the cylindrical shell due to the beam reactions. Any suggestions.

 

[jte]

PVGuy-

First, beware of thermal expansion if your're attaching the shell (exposed to sun) to the trailer rails (in the shade). Just a thought.

My approach would be to run a 1/2 symmetry model in FEA and back that analysis up with a hand calc. Take a look at Young's Roark's Formulas for Stress and Strain, 6th edition, Table 17 case 15 page 275. That's for a single rail. Playing with case 4 on page 265 will help you evaluate your double rail. Better yet, get Roark's Formulas for Stress and Strain, 4th edition and look up the same Formulas for Circular Rings table and look up case 19 which provides you with the direct formula for a self loaded ring on rails. For any case, you'll have to adjust for how the weight of the contents is transferred into the rails.

jt

 

[TomBarsh]

I am positive that "Formula's for Stress and Strain" by Roark and Young will have this case...at least as far as treating the two dimensional case.

By the way, I think that DOT (USA) has rules beyond those of ASME for pressure vessels on wheels.

 

[Engineer6512]

Vibration and shock loads would also come into play in a design such as this. It is not simply a static stress/strain relationship you are dealing with here.

Steamguy2

http://www.SteamPlantEngineering.com

- Discussion & resources for professionals in the Power Generation Industry

 

[PVGuy]

Jte and Tom Barsh,

Thank you very much for your advice. It will work here. Steamguy2, you are right; I am using some DOT requirements in addition to ASME. The DOT gives me the guidance on the items you mentioned. I use that in combination with the ring analysis to determine the reactions on the vessel in the static condition and in the dynamic conditions specifed by DOT. Thanks for pointing that out.

 

[rmw]

Are you re-inventing a wheel, or is this something that a trailer manufacturer who builds this type of vessel/trailer every day (think LPG trailers for example) could answer for you or quote you on?

rmw