Loading Calculations-NLC

Clarkie · Post by **Clarkie** » Mon Sep 17, 2007 3:58 pm

I'm looking for an individual or a business than can verify loading calculations for a customer. They are loading 2.7 Te paper reels and they want to calculate the force/weight that requires to be secured. The reels are placed on special mats that increase the coefficient of friction to 0.6. The reels are 2.0m high and are subject to 1.0g forward, 0.5g to the sides and backwards.

It's a paid job within reason

any recommendations?

Clark

Post by **Shug** » Mon Sep 17, 2007 4:06 pm

Calling Robin.....

Rag_It · Post by **Rag_It** » Mon Sep 17, 2007 4:08 pm

Scottynic · Post by **Scottynic** » Mon Sep 17, 2007 4:35 pm

there an engineer in my work who could probably work that ourt in 10secs but dont think he would appreciate me askin him

Michael · Post by **Michael** » Mon Sep 17, 2007 7:58 pm

Give Clarkie his number and he can ask him himself!

You can sit back and watch!

/prankster faction

robin · Post by **robin** » Mon Sep 17, 2007 8:13 pm

The simple fisics answer may not really be what's called for here ... suggest a real engineer gets involved

However, for amusement value only, are they being stacked flat ends down and moved singly?

If they're being moved together then you need to consider the effect the neighbours have on one another too I think.

Assuming they are flat side down and being moved singly, e.g. on a pallet lifted by a fork lift truck what is the diameter of the reel base?

Ignoring toppling for a moment, you would need a force of 45kN down the way to hold a 2.7T object still on a 0.6 CoF surface in the face of a 1g horizontal acceleration, assuming reasonable surface contact patch (if the contact patch is small, then you need to consider the material simply shearing - I assume that isn't an issue here).

You already have 27kN courtesy of the reel itself, so you would need another 18kN on top ~= 1.8T.

However to work out what sideways strapping you need to prevent them from toppling you need to know the diameter of the base. If you want to make it risky, you could allow some toppling provided you knew it would never fall, but I think that's a mistake, so better work out what's required to keep it nailed to the mat ...

If you're going to get that sideways strapping from something like one of those pallet web strap things (you know, the sort of thing boxes from MFI/IKEA are always done up with) then you also need to consider the angle they'll run at, so you'll need to know where they are anchored, and how they are connected to the reel (if they run up the sides at an angle and then down the core, that's one thing; if they run up the sides at an angle, across the flat top and then back down again at an angle, that is something completely different!).

Intuitively, there is every chance that the 47kN downwards force will also be enough to prevent it from toppling, but it does depend on the diameter of the base (imagine a 1mm base to see why this is true ...).

Cheers,
Robin

mattg · Post by **mattg** » Mon Sep 17, 2007 11:25 pm

duct tape

EliseR · Post by **EliseR** » Tue Sep 18, 2007 12:03 am

robin wrote:The simple fisics answer may not really be what's called for here ... suggest a real engineer gets involved

However, for amusement value only, are they being stacked flat ends down and moved singly?

If they're being moved together then you need to consider the effect the neighbours have on one another too I think.

Assuming they are flat side down and being moved singly, e.g. on a pallet lifted by a fork lift truck what is the diameter of the reel base?

Ignoring toppling for a moment, you would need a force of 45kN down the way to hold a 2.7T object still on a 0.6 CoF surface in the face of a 1g horizontal acceleration, assuming reasonable surface contact patch (if the contact patch is small, then you need to consider the material simply shearing - I assume that isn't an issue here).

You already have 27kN courtesy of the reel itself, so you would need another 18kN on top ~= 1.8T.

However to work out what sideways strapping you need to prevent them from toppling you need to know the diameter of the base. If you want to make it risky, you could allow some toppling provided you knew it would never fall, but I think that's a mistake, so better work out what's required to keep it nailed to the mat ...

If you're going to get that sideways strapping from something like one of those pallet web strap things (you know, the sort of thing boxes from MFI/IKEA are always done up with) then you also need to consider the angle they'll run at, so you'll need to know where they are anchored, and how they are connected to the reel (if they run up the sides at an angle and then down the core, that's one thing; if they run up the sides at an angle, across the flat top and then back down again at an angle, that is something completely different!).

Intuitively, there is every chance that the 47kN downwards force will also be enough to prevent it from toppling, but it does depend on the diameter of the base (imagine a 1mm base to see why this is true ...).

Cheers,
Robin

What he said.