An analytical model of a ring with six yield hinges and two deformable arc segments is presented for. the prediction of the buckle propagation pressure and initiation pressure in offshore pipelines. The configuration of a fully collapsed ring is considered as a real dumbbell shape with a line touch between two "bells", instead of the dumbbell shape with a point touch of two diametrically opposite points. Calculations are performed assuming that the dominant effect on the plastic energy dissipation has the circumferential bending mode. For the linear strain-hardening materials it is found that theoretical predictions based on the above model for both propagation pressure and initiation nressure are in good agreement with experimental results of Kyriakides et al.
展开▼
