Hello Friends,

Getting through (in-depth) various technical papers, references, experimental lab tests, etc. will lead you to an endless chain with no conclusion or judgement.
I believe, as far as analysis stisfies piping design code requirements, there's no need to go further, except those cases which are instructed to you by clients or other authorities.
You should trust codes and standards and follow the rules. That's why codes are changed frequently to incorporate new findings.
On the other hand, engineer must also trust software he/she uses by knowing all capabilities and getting trained properly.
For above mentioned problem, you may use FEPIPE for shell/brick finite element analysis. You can export CAESAR II models right away to FEPIPE.
Thanks to all friends that send valuable posts on this topic.