Design of Structural Steel Plate
Design of Structural Steel Plate
(OP)
Hi everyone,
I am struck at the Design of Structural Steel Plate at the base of Dumpster where it is supported by 09 nos. S Beams.
I am confused with the design of Steel plate whether it has to be designed using Roark's Equation of Stresses and Strains or simply using the Bending Criteria. My both Calculations sheets are attached.
Please guide me if I am wrong anywhere in my design approach or missing any design steps in my calculations.
Thanks in Advance.
I am struck at the Design of Structural Steel Plate at the base of Dumpster where it is supported by 09 nos. S Beams.
I am confused with the design of Steel plate whether it has to be designed using Roark's Equation of Stresses and Strains or simply using the Bending Criteria. My both Calculations sheets are attached.
Please guide me if I am wrong anywhere in my design approach or missing any design steps in my calculations.
Thanks in Advance.






RE: Design of Structural Steel Plate
RE: Design of Structural Steel Plate
Nearly all men can stand adversity, but if you want to test a man's character, give him power. Abraham Lincoln
RE: Design of Structural Steel Plate
I see that you are comparing your load against an allowable of .9Fy. I presume that this means your uniform load is already factored?
RE: Design of Structural Steel Plate
In your calculation of moment, you use a span of 0.4m.
In your calculation of Section Modulus, you use a width of 0.4m instead of 2.4m.
In your acceptance criteria, you compare fb to Fy or, more correctly φFy. This would suggest that the load is factored.
If the load is factored, your deflection calculation is wrong.
BA
RE: Design of Structural Steel Plate
BA
RE: Design of Structural Steel Plate
1) I agree with JLNJ about the continuous plate having slightly less maximum moment than what you've calculated (probably closer to wL^2/10 instead of wL^2/8, though you can double-check that).
2) I agree with BAretired about using 2.4m width for section modulus, because that is the full width of the section. Note that per AISC it is most accurate to use Z instead of S, which is a 1.5 increase for a rectangular section.
3) On the last page, though you stated phi as 0.9, it appears you accidently switched to 0.75 on the line where you multiply it by 250 MPA.
4) Deflection is primarily a concern for perceptibility (i.e. people standing on a floor would feel awkward with excessive deflection) or when the deflection would prove detrimental to any object attached to the structural member, like a brittle brick veneer on a wall. It's possible you have no such constraints here, which would render the deflection check not critical.
RE: Design of Structural Steel Plate
Thanks for your comments. Yes, we are designing the structure for such a high load (unrealistically high).
I was confused in my calculations whether to use the span of 2.4m or the clear distance between the supports i.e. 0.4 m to which I chose to use the distance between supports.
Yes, you are correct I should have check deflection under service loads not the factored loads.
Thanks JNLJ,Nor Cal SE for your comments as well. I will double check the moment in continuous span as well.
However, the prime concern is to design the structure such that it withstand the high amount of load that it will be subjected to.
Please guide on the design of plates so as to make sure that it has sufficient thickness to withstand the high loads.
The prediction of stress using Roark's equation of stress and strain is different from this calculations.
RE: Design of Structural Steel Plate
For example, it may be reasonable to treat the plate as a catenary between spans, which allows much larger spans.
Or it may be customary to arbitrarily thicken the plate over what uniform loading would suggest due to point loads.
For example, a dump truck bed would last forever if all you ever hauled it in was sand. But start hauling riprap, rubble, scrap metal, etc., and it starts getting dings in it here and there and looks bad after a while.
How is dynamic/impact loading handled (loading, unloading, hauling, dropping stuff in it)?
RE: Design of Structural Steel Plate
Service load W = 300kN
Service load w = 300/0.96 = 312.5 kPa
Span L = 0.4m
Consider end span strip one meter in width
M = wL2/10 (positive and negative) = 312.5(0.4)2/10 = 5kN-m
Factored Moment Mf = 7.5kN-m
Mr = φFy.Z = 0.9*250bt2/4 = 225bt2/4
t = (7.5*4/225b)0.5 = 11.54mm
Could use 1/2" plate.
BA
RE: Design of Structural Steel Plate
That's the approach that I'd use... to try to minimise the weight of the container.
Dik