Dynamic Load Analysis on Truck Mounted Structures

[mrsteam]

I am currently working on truck mounted equipment which includes three tanks, and an Operator's Cabin, all mounted on Hollow Structural Steel... Other equipment includes piping, and some pumps. I am particularly concerned about the dynamic loading the structural supports for the tanks and Operator's Cabin might see when travelling down the highway, and between job sites. I would assume that a rough analysis could be done using FEA, but the geometry of the model might be tough to mesh out. So, could anyone comment about:

1. The need to perform a Dynamic Load Analysis on this design (or are there rules of thumb used in the industry)

2. Who would be able to perform a QUICK analysis on our existing design (not built yet) using FEA.

Thank you very much in advance for your input.

 

[GregLocock]

1 Don't know as you haven't really identified which industry you are in. Bear in mind that the structure of the body sees about the same g levels as are acceptable to human beings, so they aren't ridiculous.

2 Bear in mind that quick usually means wrong. Do you know the vibration spectra on the chassis?

Do you have a suspension on the truck, or is it an unsprung frame at the rear?







Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[mrsteam]

Thank you Greg for your input... Here are answers as best as I can:

1. Truck is for oil and gas industry, it is a Cementing / Acidizing Unit, so it carries, besides the tanks, some heavy pumps, both centrifugal and triplex type.

2. Yes, we know "quick" tends to be wrong, but we could say I'm looking at the need for more meticulous analysis depending on rough analysis results... As far as vibration, I can't really give a number... Vibration would be the standard found on regular highways, and some more pronounced movement at much slower speeds when travelling on uneven, unpaved roads towards or in between job sites.

3. Suspension on truck: Front is spring taperleaf, Rear is tridem drive with Neway AD378 Barpin, 108" wheel base.

I hope this helps. Thanks once again.

 

[GregLocock]

1 OK

2 I'd figure on 2g dynamic loading. Would you be happy with a quasi static analysis?


3 Thanks

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[GregLocock]

Digging around it is more like 5g at the cab mountings, but it does depend on whether the cab is isolated or not.

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[RvL04]

Mrsteam;

Contract test labs like Axel Products can perform the basic analysis. (e.g.:

http://www.axelproducts.com/downloads/DynamicTest.pdf

)

FEA support groups like that of ABAQUS Great Lakes can perform the FEA for you. Try contacting todATabaqusDOTcom (a guy named Tod Dalrymple, very capable with this type of FEA!)

Ron