Perforated steel plate deflection calculation 1

[damo74]

Hi all,

I'm trying to design a perforated steel plate subject to two load cases, one of which is a ud area load, the other a point load. The steel plate is to be used as infill in a balustrade at a train station.

I have found Pounder's equation which appears fine but it applies to the deflection for a solid steel plate. Has anybody ever looked into checking the deflection of a perforated steel plate or has anybody any suggestions as to how I could modify Pounder's formula to give me a satisfactory answer? (Or can anybody recommend using another formula?)

The formula only takes into account the overall thickness of the plate, as opposed to it's moment of inertia. There are a number of other variables but none relate to it's cross sectional area. Please see attachment from "Steelwork design guide to BS5950-1:2000 - Volume 1" for formula.

Any help would be greatly appreciated.

 

[hokie66]

If you calculate the moment of inertia of a unit width of the perforated plate, then find a solid plate thickness which gives you the same I, that thickness could then be inputted into the formulas you have.

 

[damo74]

Thanks hokie66,

In this case, do you think the ud area loading could be reduced to take into account the perforations in the plate or would you apply the whole area loading over the reduced area of plate?

 

[hokie66]

That depends on the type of load. If it is wind load on the balustrade, you could perhaps reduce it, but that is tricky, and the amount of reduction depends on a lot of factors including the size and shape of openings. I wouldn't bother to try reducing the load. Any other type of load other than wind would definitely load the entire area.

 

[damo74]

Agreed.

Thanks for the help.