How thick should a steel plate be to support a load of 1300 N in a 3 point bend?

[Grant_]

I'm using the basic deflection equation to determine how thick a plate of steel would have to be to support a load of approximately 1300 N in a 3 point bend, with surface dimensions of of 420 x 630 mm.

I = bh³/12; δ = FL³/(C₁EI); E_steel = 200 GPa = 200 N/mm; δ = 50 mm (arbitrary);

h³ = 1300*(420³)*12/(48*50*630*200)

I'm getting a result of 15 mm... to me that seems a bit thick, especially when the weight would be close to 33 kg. Am I missing anything?

Thanks

 

[nvn]

Grant_: Nice work. You currently used the wrong units for E. Try again.

 

[Vadar2012]

Your value of E should be in MPa in the equation (i.e. N and mm = MPa). So E = 200000e6. So answer is 3.8 mm?

 

[lvwarren]

I usually cross check structural calculations like this with BeamCALC or some other tool.
The bookkeeping along with units variations can cause errors to creep in.