validity of CII restraint results

[M1Can]

I was doing some test cases with other structural programs, basically ran a pipe arrangement with 3 programs ( one of which is CII). The results of the two of the programs were very close 2-3% but the ceasar results were off by as much as 100% . Any ideas what may cause this , I have always just assumed CII was correct but now I have doubts

M1 Engineering

http://www.m1engineering.ca

 

[C2it]

Check your Caesar model and execution options.

 

[DSB123]

M1Can,
What are the other Programs. Remember that Caesar calculates "Code" stresses not actual stresses. These "Code" stresses are 50% of the actual stress!!!! Is that the problem??

 

[M1Can]

DSB123

Was checking forces and moments(not stress) on terminal points , sometimes on small piping that is not critical I do quick checks using another program. This time I did a check and found Ceasar was off, so I checked with a third simple finite element model now I have the structural and finite package agree but not CII. I am going to double check CII input but was just wondering if I was missing something

M1 Engineering

http://www.m1engineering.ca

 

[C2it]

Do figures for displacements agree ?

Check setting input variables such as inclusion of pressure elongation, bend opening (Bourdon effect) and ambient temperature.

Caesar does not consider any 'anchor' or restraint to be truly rigid .... a max of 1E12 of the user stiffness units. That may have an effect if your gepometry is sensitive.

I have benchmarked Caesar against most other piping packages using both static and dynamic processors, and found a good match.

 

[M1Can]

Thanks C2it , I think it may be the anchor and treating as fully rigid , I will play wit it a little more

M1 Engineering

http://www.m1engineering.ca

 

[DSB123]

Well there you go. If your models are not consistant across the different packages I guess you will get different results!!! The devil is in the detail. Your OP did not say whether you were looking at Stress results or just loads. Clarity in the questions gets clarity in the responses.