Problem:

The following message appears:

LOCAL LOADS (Cylindrical SHELL Tb1): PD 5500 Figure G.2.2-18 deflections of cyl. shells due to radial loads, values beyond curve boundaries (r/t=30,5 , L/r=1,573771)", i would like to know, what does it mean "PD 5500 Figure G.2.2-18

Why is the message appearing and how to avoid it?

Solution:

All of the design codes have some dimensional parameters based on vessel geometry which needs to be within boundaries to use the aforementioned methods. 

As the error message above indicates: 

Local loads - type of calculation being performed.

(Cylindrical SHELL Tb1): - the issue is related to Cylindrical shell with item number TB1

Designation = Cylindrical SHELL

tag = TB1:

PD5500 Figure G.2.2-18 see figure from respected code

Note: This graph was located on page G/25 of BS PD 5500 - 2012+A3 2014

(r/t=30,5 , L/r=1,573771) - AutoPIPE Vessel calculated dimensionless ratios:

- r/t=30,5  however graph range = 15 to 40

- L/r=1,573771 however graph range = 3 to 20 (Value is outside of range, Error)

Therefore you have the following options:

Option #1: Modify the parameters of the model in order for the dimesionless ratios to be within graph ranges

Option #2: Change the designing method to a different local method in AutoPIPE Vessel

Option #3: Use a Finite Element Analysis. AutoPIPE Vessel has interface with NozzlePro.

See Also

AutoPIPE Vessel

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