How to calculate platform grating load

[XPEHOC2]

Guys,
Please help or point me to the right direction,
We have a platform see attached, that mounted on to the fuel tank with gussets. Platform planks made out of 12 ga Galv material 105" Long.
Any help appreciated. Formulas , links anything.

Thanks in advance.

 

[TonyDeRamo]

What load are you trying to find? The allowable PSF on the platform? The load on the knee braces? Grating specs typically outline the allowable PSF. After figuring out what type of grating it is and the allowable load, the rest seems like simple steel design.

"Research is what I'm doing when I don't know what I'm doing."

 

[XPEHOC2]

Yes, the allowable PSF on the platform. We manufacture the planks at our facility.
Thanks,

 

[BAretired]

The live load would come from the governing building code for the appropriate use and occupancy.

The dead load requires you to estimate the volume of steel per square foot of deck and multiply by the unit weight of steel (approximately 489 pcf).

BA

 

[BAretired]

If you manufacture planks at your facility, you should have load tables for the planks for various spans.

BA

 

[XPEHOC2]

That`s the problem. We don`t fabricate them very often, just few a year, and there is no information on the loads.
No one asked us to do load calcs before....
Is there any way I can figure it out ? Is there any formulas? We have planks at our facility we have all dim`s and material specs for 12Ga galv.

Thanks

 

[structSU10]

Attached is a portion of a text that has formulation for a general grillage.

 

[msquared48]

There sould be amanufacturer out there with tables that you want.

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[BAretired]

It is not a bar grating. The sketch suggests that it is a perforated grating bent in the shape of a channel approximately 2" high and 9" wide. Look for other manufacturers who make a similar product and check their load tables.

BA

 

[kingnero]

cannot you load test it, measure deflection, get EI from that and work from there?

 

[BAretired]

Load testing is one way, but there is an easier way, namely to calculate the properties and determine the allowable load from that. You need to know the grade of steel, specifically the value of E and F_y.

In Canada, you would check against CSA S-136 the code for Cold Formed Structural Members. The effective width may be smaller than the total width for light gauge material. A different code may apply in your area.

BA

 

[MiketheEngineer]

Test them!!

 

[XPEHOC2]

I can do ANsys analysis - that is not a problem - it`ll take time to set the model up, to determine stresses and deformations, Safety factor etc... I thought that there is a formula or set of formulas that can help me to figure out that faster.
Thanks,

 

[BAretired]

The grating in this thread appears to be similar to Grip-Strut, but it may not be exactly the same. You might get a rough idea from the Grip-Strut catalog. See attached.



BA