If you are not familiar with expansion bellows please read EJMA code. It has some general information. Some bigger suppliers have freely available literature also.

Until you know how bellows works do not use any. CAESAR II cannot solve the basic engineering for you. CAESAR II has good modelling for bellows but you have to understand how it works. Some CAESAR II literature has had mistakes. COADE has updated the documentation but be carefull. Read also the earlier postings on this forum.