外压设备的抗失稳能力(稳定性)主要取决于壳体的几何尺寸，即直径、长度和壁厚，其中长度和直径起着决定性作用。
The stability of external pressure vessel mainly depends on crust's geometrical cross-section including diameter, length and wall thickness. Among them, the length and diameter are crucial.
可见到囊壁和外囊壁的环形钙化。
并应用有限元方法分析了冷弯弯头的应力状况，得出其最大应力发生点随着外拱处壁厚减薄量的增大而向外拱处转移。
The results of FEA method for cold-bending elbow predicted that the point of maximum stress is transferred from intrados to extrados with the increase of the wall thinning.
应用推荐