Abstract: Circumferential buckling or called in-plane squirm of bellows may take place whether it is subjected to external pressure or internal pressure. The problem is too complex to have been properly solved yet. In this paper, firstly the shortcomings of the usual "plastic hinges" model are revealed. Then the finite element method of Part 1 (treated as a linearized eigenvalue problem but the finite prebuckling rotations and the follower force effect of the pressure are considered) is used to calculate the circumferential buckling of bellows and the results obtained are compared with the vailable experimental ones. After that so me new explanations about the in-plane squirm are proposed.
Keywords: stability of bellows, finite element analysis, mechanism of in-plane squirm, critical loads, buckling modes.