Calculating load rating of a pulley stand

[MechEng87]

Hi Guys,

I'm a mechanical engineer looking for help with a structural problem, I work on-site at an iron ore mine in Western Australia. Typically once we design stands we get them fabricated then sent for certification. Certification involves a company putting the load which we wish to get the stand rated for on the stand itself, if it doesn't fail it gets a certification plaque.

I was required to design a stand for a conveyor pulley (drawing attached), I want this stand rated for at least 10T. I know the sections I have used will take in excess of 10T but what calculations should I perform as a check? The castors are off the shelf items each with a load rating of 5T so I won't check their structural integrity. My question is what calculations would you perform as a quick check and how do I do them? So far I was thinking I should check the flat bar and UB in compression, what forumlas should I use? Do I need to check the bottom channel for compression along the web?

Is there any other website I should post this query to?

Thanks,
Conor

 

[Studiot]

Whilst I'm suprised RTZ can't pay for its own structural analysis I would comment that the weak point in the design will be items 6, the pulley mounting flanges and their connection to member 3.

If member 3 were a bit wider then items 6 could be stiffened against torsional effects, that may eventually cause the rather small weld line connection to fail.
Alternatively members 6 could remain flat but be continued down the sides of member 3.

go well