How would I figure the load/weight capacity of a homemade cart used to move around heavy alloy bars?

[MrMetals]

We have some utility carts that our warehouse uses to move around heavy alloy bars and pipes. These carts were homemade many years ago and now need to be rated by capacity. Any idea of where I would start in figuring this out? I can get the material properties no prob, but I don't know where to start from the mechanical side of things. Any ideas? I know I need to take the welds into consideration and the design( which is a x on both sides connected by a cross member, all riding on four heavy duty caster wheels).Any help would be appreciated.

 

[PEinc]

Hire an engineer who actually does design work.

http://www.PeirceEngineering.com

 

[msquared48]

This is not a mechanical engineering problem. It is a structural engineering problem.

Hire a structural engineer.

Mike McCann, PE, SE (WA)

 

[MrMetals]

thanks for the tip.....I was actually looking do some preliminary calculations prior to hiring someone to actually rate it. Is this small of a job something a struc. would take on?

 

[oldestguy]

Maybe a structural engineer can answer the question. However, there may be cast iron wheels and cast iron "housing" for them that may be difficult to assess.

I'd consider what we do for testing slings, etc. OSHA has accepted my testing of apparently weakened slings this way, so why not other gear? You know the weight of the stuff you carry. What is to stop you from overloading a representative cart with known weights? If it does not fail and can operate with say a 25 or 50 percent overlad from typical loads, you should have pretty solid proof of their capabilities.

 

[Ron]

Do a proof load test. Beats calculations every time!

 

[RHTPE]

Ron is absolutely correct. It's the simplest way to establish a safe working load.

To validate for OSHA, it may require a report or statement from a qualified, licensed engineer be in your records. Chances are he/she will likely want to observe the test.


Ralph
Structures Consulting
Northeast USA

 

[msquared48]

When it fails, you can build a new one and test that one too, then another, and another......

Mike McCann, PE, SE (WA)

 

[desertfox]

Hi

Have you any pictures or drawings of these carts?

 

[oldestguy]

If you want to get fancy, arrange with a large testing facility to do it in a compression testing machine,as one might test pre-cast concrete beams.