Hi

There is simple piping system that was modelled in CII 2016, later it had to be re-modelled in CII 2013 as the end user did not have the latest version.

CII comes up with a different set of results from both versions.

For example, we have W+P1, WNC and W load cases. In the Restraint Summary, numbers from WNC and W exactly match between both versions, however for the W+P1 numbers from CII 2016 do not match CII 2013.

We have checked the input to ensure P1, Bourdon activation in both the versions are identical, also did normal checks a user would do.

Please advise if there is something that has been missed out that causes the discrepancy.

Felix

Are you saying the restraint loads are different in your W+P1 cases? How different are they?
What happens when you run P1 alone in both programs?
If it's only a difference in calculated pressure stress, the difference may be caused by the equation used to calculate the longitudinal pressure stress - one may be using PD/4t and the other may be using P(A-in)/(A-xs). This is a configuration file setting.
Is this a B31.3 analysis?
As you can see, more details are required.

Dave
Thanks for looking into my query.

The system is being analysed to B31.3. Yes, the restraint loads are different in W+P1 cases. Please see below an extract from the restraint summary.

When a P1 (SUS) alone is run, at the node cited below, the restraint loads are zero in both programs.

I had PD/4t set as “False” in both programs.

I am attaching zip files of both calc’s. That will provide you with the details required.

Felix

ps: AdditionalIy, we checked by opening the CII 2013 model using CII 2016 (reverse of my initial exercise), in that instance the results matched.

CII 2016 (V8)
LOAD CASE DEFINITION KEY

CASE 1 (OPE) W+D1+T1+P1
CASE 2 (OPE) W+D1+T2+P1
CASE 3 (OPE) W+D1+T3+P1
CASE 4 (SUS) W+P1
CASE 5 (SUS) WNC
CASE 6 (SUS) W

Node Load Case FX N. FY N. FZ N. MX N.m. MY N.m. MZ N.m.
70 Rigid +Y
1(OPE) -215 -2535 118 0 0 0
2(OPE) -220 -2556 113 0 0 0
3(OPE) 27 -2068 205 0 0 0
4(SUS) 0 -2641 0 0 0 0
5(SUS) 4 -1853 185 0 0 0
6(SUS) -22 -2056 204 0 0 0

CII 2013 (V6)
LOAD CASE DEFINITION KEY

CASE 1 (OPE) W+D1+T1+P1
CASE 2 (OPE) W+D1+T2+P1
CASE 3 (OPE) W+D1+T3+P1
CASE 4 (SUS) W+P1
CASE 5 (SUS) WNC
CASE 6 (SUS) W


Node Load Case FX N. FY N. FZ N. MX N.m. MY N.m. MZ N.m.
70 Rigid +Y
1(OPE) -232 -2590 106 0 0 0
2(OPE) -237 -2613 101 0 0 0
3(OPE) 29 -2068 205 0 0 0
4(SUS) -21 -2051 204 0 0 0
5(SUS) 4 -1853 185 0 0 0
6(SUS) -22 -2056 204 0 0 0

because in the V8 file, you set friction multiplier as 0 in case 4. but in V6 file, friction is set to 1 for the similar load case.

and your OPE loads differences may be explained by the fact that the data for thermal expansion in B31.3 2014 (used by CII 2016) has changed slightly compared to code version 2012 and earlier.

Thanks Faizal, you are spot on.