Support bracket gusset plate thickness

[pvengineer]

Does anyone have the AISC formula used to calculate the gusset plate thickness for a support bracket with two gusset plates and a top plate and base plate. In particular the one used in PVElite2004 program.

 

[Shmulik]

You may see at Bednar's "Pressure Vessel Design Handbook": 5.2. Support Lugs.

 

[nuche1973]

I agree with Shmulik. Bednar has a great example of what you are looking for.

 

[pvengineer]

Thanks Shmulik and nuche1973 for quick response. I have looked and applied Bednar formula and it comes out with a thickness of 13mm compared to the PVElite2004 program thickness based on AISC of 18mm. I am not familiar with AISC. In the PVElite2004 manual, it makes mention of AISC 5.2, which I am trying to find to see the formula the program uses.

 

[JStephen]

Are you sure the 5.2 reference is correct?

I believe the latest AISC code is a free download from AISC (not the whole reference book that it is normally found in, but the code itself.) But the sections and equations are generally preceded by a letter in the body of the code.

 

[pvengineer]

I made a mistake quoting AISC 5.2. The PVElite2004 manual does not mention AISC 5.2.

 

[JStephen]

It's possible the program is applying a standard compressive stress/column design, or setting the width to match compact-section criteria or something like that, as opposed to a design specifically for your geometry.

 

[pvengineer]

Can anyone explain the Bednar example 5.2 calculation of the gusset plate radius of gyration r = 0.289 x 0.625 I am not clear where these numbers are coming from in the example and what radius of gyration equation is being used here for the gusset plate.

I thought the radius of gyration was sqrt(I/A).

The example also states the buckling length of 22in when the overall height of the the support bracket is only 20in. I assume the gusset plate buckling length is taken as the overall length plus the weld throat thicknesses at the top of the top plate and bottom of the bottom bolting plate.