The MAWP calculation of reinforcement

[Greenbee]

My question is NOT about governing issue. My question is how the MAWP of reinforcement is calculated. The commercial software only gives the results of MAWP at the reinforced area. None of them gives the calculation procedure. Any book and manual have the detail steps and procedure to derive the MAWP of opening/reinforcement area per available area and required area. I figured out the following steps.

The thickest value can be removed or used to calculate the MAWP per reinforcement as
trm = 1.0 / 2.0 / d / F * (d * E * ts - 2.0 * tn * E1 * ts * (1.0 - fr1) + A2 + A3 + A41 + A42 + A43 + A5).................(1)

For opening on cylinder case, we have the Reinforcement MAWP = S * E * trm / (R + 0.6 * trm)..................(2)

But, the problem is that A2 in equation (1) is related to internal pressure or reinforcement MAWP.

Anyone has the clue to derive the equation for the Reinforcement MAWP directly.

 

[SnTMan]

Greenbee, both tn and trn are functions of pressure. All the quantities A, Ax, will vary with pressure. I am not aware of a means to calculate MAWP directly. The usual procedure is to increment the pressure, holding all dimension constant, until the reinforcement calculations fail. The previous pressure, for which the reinforcement was just adequate, is the MAWP.

I don't know what you mean by "trm".

EDIT: not tn, tr

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[Greenbee]

Mike,

Thanks for your response. The "trm" is the maximum shell thickness removed. It times the opening size equal to the available area.

 

[r6155]

Exactly as SnTMan says.
With my spreadsheet I increase the design pressure in steps until it fails.

Regards

 

[SnTMan]

Yes. I might have said, easy to do with a computer, hard to do by hand

The problem with sloppy work is that the supply FAR EXCEEDS the demand