Issue of the value of wave number N for tank wall instability theory in external pressure calculations per GB50341-2014
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This post was last edited by wx_Catherine_Mi on 2021-7-16 09:08. Question: 1. In Appendix B of GB50341-2014, the formula for the theoretical wavenumber N related to tank wall instability is given in B.4.1, and it is required that N be between 2 and 10. What should I do if the N value I calculate is greater than 10? Should other values be adjusted so that N is between 2 and 10, or should a value within that range be chosen; if it’s less than 2, then 2 should be used, and if it’s greater than 10, then 10 should be used? (Referring to API 650, it should be >10; in that case, take 10.) ) 2. The minimum inertial moment required for the top and bottom reinforcement rings is a positive value, while the minimum cross-sectional area required is a negative value; how should these values be chosen? A negative value should indicate that no reinforcement ring is needed. I would appreciate your guidance; thank you!
Although I have no evidence, I strongly suspect that you’re here to take advantage of that wealth
That can’t be the case; the standards are written right there. I checked API650 today; there’s an example in it where N>10, so 10 should be used. That’s what it seems, so let’s go with that for now.
The new standard imposes limits on the wind resistance ring; if those limits are exceeded, it is calculated as an external pressure vessel. I don’t understand it either, but we have to follow the standards anyway