Deck Slab

[SubseaDeep]

Hi All,

Can someone please advise on some article which tells us how to calculate a deck's load capacity with stiffeners underneath it? For example, I have a half inch thick, A36 steel deck, and is 50 ft by 20 ft long. Along the length I have W8 I-beams spaced at 10 ft distance all along the length of the deck. Between any two I-beams, there are 3" x 3" L-angles welded to them, to stiffen the deck. Can someone advise where can I find a suitable literature to calculate the lbs/in^2 deck capacity please?

Regards,

SubseaDeep

 

[ishvaaag]

I think you can model well it with FEM programs as of now; best of course with ones abe to portrait the nonlinear behaviour of the materials. This way you can quite accurately follow the deformation of your deck as loads grow. Even with a mere linear linear behaviour of the materials you can get insight of the zones attaining plastification by looking the Von Mises stress; and if you have some plastified areas you know your displacements are underrepresented in such elastic model.

You must include also geometrical nonlinearity; both material and geometrical nonlinearities must be represented in the model for a modern evaluation of the strength and serviceability of your deck.

More classical approaches are in orthotropic plates theory.
The

Structural Steel Designer's Handbook
Brockenbrough
Merrit
McGraw Hill ed.
I have second edition
has a section and many things about orthotropic plates (see index)

On the particular aspect of buckling of orthotropic plates (when there's compression in the orthotropic plate's plane) Galambos'
Guide to Stability design criteria for metal structures 5th edition
have a nice section on it.

Really by now with the use of FEM models orthotropic plates have been subsumed in ordinary design procedures, and you should find cozier to use it if only because it is what one is doing for everything else. Before there were doubts as to how much plate could be considering collaborating as effective width etc but all these things are automatically encompassed now in a sound FEM design.

 

[Ron]

You haven't given much info, but essentially any structural engineering text would give you background sufficient to do this. I doubt that you'll find an article that will do this for you or give you specific guidance on your parameters.

[highlight]You might consider getting a structural engineer involved.[/highlight] You have a few considerations to make such as plate bending, restraint conditions for the beams, column types and locations, serviceability, end use, etc.

How much capacity to you need? Incidentally, loading on decks or platforms such as this is usually given in psf not psi.

 

[oneintheeye]

are you a structural engineer looking for advice or a mechanical guy looking to save a buck? If the later you should consider employing someone who knows how to do the analysis, from a legal aspect if anyhting goes wrong at least. i.e. you in the dock.

 

[JAE]

I can positively state you have at least 2 psf capacity.

 

[BAretired]

Your description of the geometry is not totally clear. Provide a drawing and we may be able to advise how best to proceed.

BA

 

[SubseaDeep]

Hi All,

Thanks for your comments. BA, I will provide a sketch which will explain more. Herewego, I am not trying to save any buck, but just trying to get a finer idea on structural decks theoretically. Ish and Ron thanks for your comments. The main problem is that I am not being able to find a good written engineering article which would explain properly. But will see Structural Steel Designer's Handbook as mentioned by Ishvaag.

Regards,

SubseaDeep