Plate Thickness Design

[packie81]

I have a problem, I think I solved it myself, BUT I would like a second opinion:

I have a plate 24.375"x23" with an 18,000lbs load in the centre. It's not a point load, it is load from a forklift tire, so I considered the load to be on a 4" radius circle in the centre. I want to know how thick the plate should be, given it is going to be made from A36 steel plate, with a safety factor of 2 therefore a maximum design stress of 18,000psi.

Thanks,
Steve Mackie, Product/Applications Engineer
Apical Conveyor Systems, Inc.
Tavistock, Ontario

 

[Lcubed]

Edge conditions are critical. How are the edges fixed or supported?

 

[packie81]

Oops, forgot to include that. Consider the plate to be rigidly supported around the perimeter. Steve Mackie, Product/Applications Engineer
Apical Conveyor Systems, Inc.
Tavistock, Ontario

 

[PEStructural]

Hi Steve,

For a plate to be "rigidly fixed", it means that the edges of the plates can transmit moment into the structure that is supporting the plate. What type of connection is it? ... Bolted, welded, embedded? The actual edge condition will govern what type of edge condition to use.

Hope this helps,

Mike

 

[packie81]

Consider it to be welded continuous around the perimeter. The welding doesn't really concern be, the weakest point of this structure is going to be the centre of this plate.

Steve Steve Mackie, Product/Applications Engineer
Apical Conveyor Systems, Inc.
Tavistock, Ontario

 

[DRex]

ABS Shipbuilding rules deal with this problem, go to

http://www.eagle.org/rules/downloads/SVR2002/Part 3.pdf

and then to page 80.

Alternatively Roarkes Formulas Art. 10.11 give formulas to calculate stress for various edge conditions.