Calculations for Stiffened alloy plate

[peteobyrne]

Hi,

I am a recent graduate and am designing a cover for a wood chip hopper which is inset into the ground. The cover is to be made from 8mm Alloy treadplate with 100x10 Alloy flat stiffeners welded in underneath it. The cover will be supported on all four sides and the worst case scenario will be if a truck parks a wheel on the centre of the cover (approx 2000kg). I am wanting to do some calcs to make sure that it will hold up but have left the relevant txt book at one of my previous flats.

Could someone point me in the right direction as to where to figure this one out.

Cheers,

Pete.

 

[Bagman2524]

Roark's formulas for stress and strain is a good source for evaluated stresses and deflections in flat plates. Alternately, you could assume the stiffeners and plate act as a T-beam section with the top being a width of 16t. If the load is entirely on one of the stiffeners, then a single "T section" would have to carry the load.

 

[peteobyrne]

Thanks Bagman, I don't really know why I didn't think of that myself. How did you come up with a value of 16T though? Is this a standard assumption?

Thanks once again for the help.

Pete

 

[miecz]

Sixteen times the plate thickness is a quick and dirty effective width unless you want to get more precise. If you need something more precise, get your hands on a cold formed steel design book. In the US, the Manual is published by AISI. Also, I think Bloggett's welded steel construction book (forget the exact name) has a good section on stiffened plates.

 

[peteobyrne]

Thanks miecz, I figured it would be something like that. Quick and dirty is fine for this application.

Cheers for the help.

Pete