Calculation lengths for external pressure of the two cylinder sections
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It is a vertical double-layer container, with the inner container consisting of two cylinders of different wall thicknesses joined together; for example, the diameter is 2400, and the upper and lower ends are elliptical heads. The length of the lower cylinder is 3000, while that of the upper cylinder is 9000. How should external pressure calculations be carried out? How should the external pressure calculation length be selected?
We calculate based on the assumption that all 12m sections are thin cylinders, which is a conservative approach
At the joints of different cylinder wall thicknesses, which serve as segmentation lines, the thicknesses of the two sections of the cylinder are calculated separately; however, these junction lines need to be considered as support lines.
This post was last edited by SDHZZXM on 2019-3-10 at 14:51. Should the connection wire be considered as a support wire? That can’t be right. It seems it doesn’t meet the conditions to be a support line.
The external pressure calculation length for both sections is considered based on the total length, which is 12480 mm. Since the diameters of the cylinders with different thicknesses are the same, it is assumed that the material is identical and thus thin-walled calculations are applied; if the materials differ, separate calculations are carried out.
If the connecting wire cannot be used as a support wire (no reinforcing ring can be added), use a thin wall, calculated based on the total length of the cylinder.
Reinforcement rings are provided at the joints, to be considered separately； Overall, go with the thin one.